new file mode 100644
--- /dev/null
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -0,0 +1,2691 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+
+
+#define NGX_HTTP_MP4_TRAK_ATOM     0
+#define NGX_HTTP_MP4_TKHD_ATOM     1
+#define NGX_HTTP_MP4_MDIA_ATOM     2
+#define NGX_HTTP_MP4_MDHD_ATOM     3
+#define NGX_HTTP_MP4_HDLR_ATOM     4
+#define NGX_HTTP_MP4_MINF_ATOM     5
+#define NGX_HTTP_MP4_VMHD_ATOM     6
+#define NGX_HTTP_MP4_SMHD_ATOM     7
+#define NGX_HTTP_MP4_DINF_ATOM     8
+#define NGX_HTTP_MP4_STBL_ATOM     9
+#define NGX_HTTP_MP4_STSD_ATOM    10
+#define NGX_HTTP_MP4_STTS_ATOM    11
+#define NGX_HTTP_MP4_STTS_DATA    12
+#define NGX_HTTP_MP4_STSS_ATOM    13
+#define NGX_HTTP_MP4_STSS_DATA    14
+#define NGX_HTTP_MP4_CTTS_ATOM    15
+#define NGX_HTTP_MP4_CTTS_DATA    16
+#define NGX_HTTP_MP4_STSC_ATOM    17
+#define NGX_HTTP_MP4_STSC_CHUNK   18
+#define NGX_HTTP_MP4_STSC_DATA    19
+#define NGX_HTTP_MP4_STSZ_ATOM    20
+#define NGX_HTTP_MP4_STSZ_DATA    21
+#define NGX_HTTP_MP4_STCO_ATOM    22
+#define NGX_HTTP_MP4_STCO_DATA    23
+
+#define NGX_HTTP_MP4_LAST_ATOM    NGX_HTTP_MP4_STCO_DATA
+
+
+typedef struct {
+    size_t                buffer_size;
+    size_t                max_buffer_size;
+} ngx_http_mp4_conf_t;
+
+
+typedef struct {
+    u_char                chunk[4];
+    u_char                samples[4];
+    u_char                id[4];
+} ngx_mp4_stsc_entry_t;
+
+
+typedef struct {
+    uint32_t              timescale;
+    uint32_t              time_to_sample_entries;
+    uint32_t              sample_to_chunk_entries;
+    uint32_t              sync_samples_entries;
+    uint32_t              composition_offset_entries;
+    uint32_t              sample_sizes_entries;
+    uint32_t              chunks;
+
+    ngx_uint_t            start_sample;
+    ngx_uint_t            start_chunk;
+    ngx_uint_t            chunk_samples;
+    ngx_uint_t            chunk_samples_size;
+    off_t                 start_offset;
+
+    size_t                tkhd_size;
+    size_t                mdhd_size;
+    size_t                hdlr_size;
+    size_t                vmhd_size;
+    size_t                smhd_size;
+    size_t                dinf_size;
+    size_t                size;
+
+    ngx_chain_t           out[NGX_HTTP_MP4_LAST_ATOM + 1];
+
+    ngx_buf_t             trak_atom_buf;
+    ngx_buf_t             tkhd_atom_buf;
+    ngx_buf_t             mdia_atom_buf;
+    ngx_buf_t             mdhd_atom_buf;
+    ngx_buf_t             hdlr_atom_buf;
+    ngx_buf_t             minf_atom_buf;
+    ngx_buf_t             vmhd_atom_buf;
+    ngx_buf_t             smhd_atom_buf;
+    ngx_buf_t             dinf_atom_buf;
+    ngx_buf_t             stbl_atom_buf;
+    ngx_buf_t             stsd_atom_buf;
+    ngx_buf_t             stts_atom_buf;
+    ngx_buf_t             stts_data_buf;
+    ngx_buf_t             stss_atom_buf;
+    ngx_buf_t             stss_data_buf;
+    ngx_buf_t             ctts_atom_buf;
+    ngx_buf_t             ctts_data_buf;
+    ngx_buf_t             stsc_atom_buf;
+    ngx_buf_t             stsc_chunk_buf;
+    ngx_buf_t             stsc_data_buf;
+    ngx_buf_t             stsz_atom_buf;
+    ngx_buf_t             stsz_data_buf;
+    ngx_buf_t             tsco_atom_buf;
+    ngx_buf_t             tsco_data_buf;
+
+    ngx_mp4_stsc_entry_t  stsc_chunk_entry;
+} ngx_http_mp4_trak_t;
+
+
+typedef struct {
+    ngx_file_t            file;
+
+    u_char               *buffer;
+    u_char               *buffer_start;
+    u_char               *buffer_pos;
+    u_char               *buffer_end;
+    size_t                buffer_size;
+
+    off_t                 offset;
+    off_t                 end;
+    off_t                 content_length;
+    ngx_uint_t            start;
+    uint32_t              timescale;
+    ngx_http_request_t   *request;
+    ngx_array_t           trak;
+    ngx_http_mp4_trak_t   traks[2];
+
+    size_t                ftyp_size;
+    size_t                moov_size;
+
+    ngx_chain_t          *out;
+    ngx_chain_t           ftyp_atom;
+    ngx_chain_t           moov_atom;
+    ngx_chain_t           mvhd_atom;
+    ngx_chain_t           mdat_atom;
+    ngx_chain_t           mdat_data;
+
+    ngx_buf_t             ftyp_atom_buf;
+    ngx_buf_t             moov_atom_buf;
+    ngx_buf_t             mvhd_atom_buf;
+    ngx_buf_t             mdat_atom_buf;
+    ngx_buf_t             mdat_data_buf;
+
+    u_char                moov_atom_header[8];
+    u_char                mdat_atom_header[16];
+} ngx_http_mp4_file_t;
+
+
+typedef struct {
+    char                 *name;
+    ngx_int_t           (*handler)(ngx_http_mp4_file_t *mp4,
+                                   uint64_t atom_data_size);
+} ngx_http_mp4_atom_handler_t;
+
+
+#define ngx_mp4_atom_header(mp4)   (mp4->buffer_pos - 8)
+#define ngx_mp4_atom_data(mp4)     mp4->buffer_pos
+#define ngx_mp4_atom_next(mp4, n)  mp4->buffer_pos += n; mp4->offset += n
+
+
+#define ngx_mp4_set_atom_name(p, n1, n2, n3, n4)                              \
+    ((u_char *) (p))[4] = n1;                                                 \
+    ((u_char *) (p))[5] = n2;                                                 \
+    ((u_char *) (p))[6] = n3;                                                 \
+    ((u_char *) (p))[7] = n4
+
+#define ngx_mp4_get_32value(p)                                                \
+    ( (((u_char *) (p))[0] << 24)                                             \
+    + (((u_char *) (p))[1] << 16)                                             \
+    + (((u_char *) (p))[2] << 8)                                              \
+    + (((u_char *) (p))[3]) )
+
+#define ngx_mp4_set_32value(p, n)                                             \
+    ((u_char *) (p))[0] = (u_char) ((n) >> 24);                               \
+    ((u_char *) (p))[1] = (u_char) ((n) >> 16);                               \
+    ((u_char *) (p))[2] = (u_char) ((n) >> 8);                                \
+    ((u_char *) (p))[3] = (u_char)  (n)
+
+#define ngx_mp4_get_64value(p)                                                \
+    ( ((uint64_t) ((u_char *) (p))[0] << 56)                                  \
+    + ((uint64_t) ((u_char *) (p))[1] << 48)                                  \
+    + ((uint64_t) ((u_char *) (p))[2] << 40)                                  \
+    + ((uint64_t) ((u_char *) (p))[3] << 32)                                  \
+    + ((uint64_t) ((u_char *) (p))[4] << 24)                                  \
+    + (           ((u_char *) (p))[5] << 16)                                  \
+    + (           ((u_char *) (p))[6] << 8)                                   \
+    + (           ((u_char *) (p))[7]) )
+
+#define ngx_mp4_set_64value(p, n)                                             \
+    ((u_char *) (p))[0] = (u_char) ((n) >> 56);                               \
+    ((u_char *) (p))[1] = (u_char) ((n) >> 48);                               \
+    ((u_char *) (p))[2] = (u_char) ((n) >> 40);                               \
+    ((u_char *) (p))[3] = (u_char) ((n) >> 32);                               \
+    ((u_char *) (p))[4] = (u_char) ((n) >> 24);                               \
+    ((u_char *) (p))[5] = (u_char) ((n) >> 16);                               \
+    ((u_char *) (p))[6] = (u_char) ((n) >> 8);                                \
+    ((u_char *) (p))[7] = (u_char) (n)
+
+#define ngx_mp4_last_trak(mp4)                                                \
+    &((ngx_http_mp4_trak_t *) mp4->trak.elts)[mp4->trak.nelts - 1]
+
+
+static ngx_int_t ngx_http_mp4_process(ngx_http_mp4_file_t *mp4);
+static ngx_int_t ngx_http_mp4_read_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_atom_handler_t *atom, uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read(ngx_http_mp4_file_t *mp4);
+static ngx_int_t ngx_http_mp4_read_ftyp_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_moov_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_mdat_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static size_t ngx_http_mp4_update_mdat_atom(ngx_http_mp4_file_t *mp4,
+    off_t start_offset);
+static ngx_int_t ngx_http_mp4_read_mvhd_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_trak_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static void ngx_http_mp4_update_trak_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_cmov_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_tkhd_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_mdia_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static void ngx_http_mp4_update_mdia_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_mdhd_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_hdlr_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_minf_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static void ngx_http_mp4_update_minf_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_dinf_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_vmhd_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_smhd_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_stbl_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static void ngx_http_mp4_update_stbl_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_stsd_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_read_stts_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_update_stts_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_stss_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_update_stss_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_ctts_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static void ngx_http_mp4_update_ctts_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_stsc_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_update_stsc_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_stsz_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static void ngx_http_mp4_update_stsz_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static ngx_int_t ngx_http_mp4_read_stco_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_update_stco_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static void ngx_http_mp4_adjust_stco_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak, int32_t adjustment);
+static char *ngx_http_mp4(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
+static void *ngx_http_mp4_create_conf(ngx_conf_t *cf);
+static char *ngx_http_mp4_merge_conf(ngx_conf_t *cf, void *parent, void *child);
+
+static ngx_command_t  ngx_http_mp4_commands[] = {
+
+    { ngx_string("mp4"),
+      NGX_HTTP_LOC_CONF|NGX_CONF_NOARGS,
+      ngx_http_mp4,
+      0,
+      0,
+      NULL },
+
+    { ngx_string("mp4_buffer_size"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_size_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_mp4_conf_t, buffer_size),
+      NULL },
+
+    { ngx_string("mp4_max_buffer_size"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_size_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_mp4_conf_t, max_buffer_size),
+      NULL },
+
+      ngx_null_command
+};
+
+
+static ngx_http_module_t  ngx_http_mp4_module_ctx = {
+    NULL,                          /* preconfiguration */
+    NULL,                          /* postconfiguration */
+
+    NULL,                          /* create main configuration */
+    NULL,                          /* init main configuration */
+
+    NULL,                          /* create server configuration */
+    NULL,                          /* merge server configuration */
+
+    ngx_http_mp4_create_conf,      /* create location configuration */
+    ngx_http_mp4_merge_conf        /* merge location configuration */
+};
+
+
+ngx_module_t  ngx_http_mp4_module = {
+    NGX_MODULE_V1,
+    &ngx_http_mp4_module_ctx,      /* module context */
+    ngx_http_mp4_commands,         /* module directives */
+    NGX_HTTP_MODULE,               /* module type */
+    NULL,                          /* init master */
+    NULL,                          /* init module */
+    NULL,                          /* init process */
+    NULL,                          /* init thread */
+    NULL,                          /* exit thread */
+    NULL,                          /* exit process */
+    NULL,                          /* exit master */
+    NGX_MODULE_V1_PADDING
+};
+
+
+static ngx_http_mp4_atom_handler_t  ngx_http_mp4_atoms[] = {
+    { "ftyp", ngx_http_mp4_read_ftyp_atom },
+    { "moov", ngx_http_mp4_read_moov_atom },
+    { "mdat", ngx_http_mp4_read_mdat_atom },
+    { NULL, NULL }
+};
+
+static ngx_http_mp4_atom_handler_t  ngx_http_mp4_moov_atoms[] = {
+    { "mvhd", ngx_http_mp4_read_mvhd_atom },
+    { "trak", ngx_http_mp4_read_trak_atom },
+    { "cmov", ngx_http_mp4_read_cmov_atom },
+    { NULL, NULL }
+};
+
+static ngx_http_mp4_atom_handler_t  ngx_http_mp4_trak_atoms[] = {
+    { "tkhd", ngx_http_mp4_read_tkhd_atom },
+    { "mdia", ngx_http_mp4_read_mdia_atom },
+    { NULL, NULL }
+};
+
+static ngx_http_mp4_atom_handler_t  ngx_http_mp4_mdia_atoms[] = {
+    { "mdhd", ngx_http_mp4_read_mdhd_atom },
+    { "hdlr", ngx_http_mp4_read_hdlr_atom },
+    { "minf", ngx_http_mp4_read_minf_atom },
+    { NULL, NULL }
+};
+
+static ngx_http_mp4_atom_handler_t  ngx_http_mp4_minf_atoms[] = {
+    { "vmhd", ngx_http_mp4_read_vmhd_atom },
+    { "smhd", ngx_http_mp4_read_smhd_atom },
+    { "dinf", ngx_http_mp4_read_dinf_atom },
+    { "stbl", ngx_http_mp4_read_stbl_atom },
+    { NULL, NULL }
+};
+
+static ngx_http_mp4_atom_handler_t  ngx_http_mp4_stbl_atoms[] = {
+    { "stsd", ngx_http_mp4_read_stsd_atom },
+    { "stts", ngx_http_mp4_read_stts_atom },
+    { "stss", ngx_http_mp4_read_stss_atom },
+    { "ctts", ngx_http_mp4_read_ctts_atom },
+    { "stsc", ngx_http_mp4_read_stsc_atom },
+    { "stsz", ngx_http_mp4_read_stsz_atom },
+    { "stco", ngx_http_mp4_read_stco_atom },
+    { NULL, NULL }
+};
+
+
+static ngx_int_t
+ngx_http_mp4_handler(ngx_http_request_t *r)
+{
+    u_char                    *last;
+    size_t                     root;
+    ngx_int_t                  rc, start;
+    ngx_uint_t                 level;
+    ngx_str_t                  path, value;
+    ngx_log_t                 *log;
+    ngx_buf_t                 *b;
+    ngx_chain_t                out;
+    ngx_http_mp4_file_t       *mp4;
+    ngx_open_file_info_t       of;
+    ngx_http_core_loc_conf_t  *clcf;
+
+    if (!(r->method & (NGX_HTTP_GET|NGX_HTTP_HEAD))) {
+        return NGX_HTTP_NOT_ALLOWED;
+    }
+
+    if (r->uri.data[r->uri.len - 1] == '/') {
+        return NGX_DECLINED;
+    }
+
+    rc = ngx_http_discard_request_body(r);
+
+    if (rc != NGX_OK) {
+        return rc;
+    }
+
+    last = ngx_http_map_uri_to_path(r, &path, &root, 0);
+    if (last == NULL) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    log = r->connection->log;
+
+    path.len = last - path.data;
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, log, 0,
+                   "http mp4 filename: \"%V\"", &path);
+
+    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
+
+    ngx_memzero(&of, sizeof(ngx_open_file_info_t));
+
+    of.read_ahead = clcf->read_ahead;
+    of.directio = NGX_MAX_OFF_T_VALUE;
+    of.valid = clcf->open_file_cache_valid;
+    of.min_uses = clcf->open_file_cache_min_uses;
+    of.errors = clcf->open_file_cache_errors;
+    of.events = clcf->open_file_cache_events;
+
+    if (ngx_open_cached_file(clcf->open_file_cache, &path, &of, r->pool)
+        != NGX_OK)
+    {
+        switch (of.err) {
+
+        case 0:
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+
+        case NGX_ENOENT:
+        case NGX_ENOTDIR:
+        case NGX_ENAMETOOLONG:
+
+            level = NGX_LOG_ERR;
+            rc = NGX_HTTP_NOT_FOUND;
+            break;
+
+        case NGX_EACCES:
+
+            level = NGX_LOG_ERR;
+            rc = NGX_HTTP_FORBIDDEN;
+            break;
+
+        default:
+
+            level = NGX_LOG_CRIT;
+            rc = NGX_HTTP_INTERNAL_SERVER_ERROR;
+            break;
+        }
+
+        if (rc != NGX_HTTP_NOT_FOUND || clcf->log_not_found) {
+            ngx_log_error(level, log, of.err,
+                          "%s \"%s\" failed", of.failed, path.data);
+        }
+
+        return rc;
+    }
+
+    if (!of.is_file) {
+
+        if (ngx_close_file(of.fd) == NGX_FILE_ERROR) {
+            ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
+                          ngx_close_file_n " \"%s\" failed", path.data);
+        }
+
+        return NGX_DECLINED;
+    }
+
+    r->root_tested = !r->error_page;
+    r->allow_ranges = 1;
+
+    start = -1;
+    r->headers_out.content_length_n = of.size;
+    mp4 = NULL;
+    b = NULL;
+
+    if (r->args.len) {
+
+        if (ngx_http_arg(r, (u_char *) "start", 5, &value) == NGX_OK) {
+
+            start = ngx_atofp(value.data, value.len, 3);
+
+            if (start != NGX_ERROR) {
+                r->allow_ranges = 0;
+
+                mp4 = ngx_pcalloc(r->pool, sizeof(ngx_http_mp4_file_t));
+                if (mp4 == NULL) {
+                    return NGX_HTTP_INTERNAL_SERVER_ERROR;
+                }
+
+                mp4->file.fd = of.fd;
+                mp4->file.name = path;
+                mp4->file.log = r->connection->log;;
+                mp4->end = of.size;
+                mp4->start = (ngx_uint_t) start;
+                mp4->request = r;
+
+                switch (ngx_http_mp4_process(mp4)) {
+
+                case NGX_DECLINED:
+                    if (mp4->buffer) {
+                        ngx_pfree(r->pool, mp4->buffer);
+                    }
+
+                    ngx_pfree(r->pool, mp4);
+                    mp4 = NULL;
+
+                    break;
+
+                case NGX_OK:
+                    r->headers_out.content_length_n = mp4->content_length;
+                    break;
+
+                default: /* NGX_ERROR */
+                    if (mp4->buffer) {
+                        ngx_pfree(r->pool, mp4->buffer);
+                    }
+
+                    ngx_pfree(r->pool, mp4);
+
+                    return NGX_HTTP_INTERNAL_SERVER_ERROR;
+                }
+            }
+        }
+    }
+
+    log->action = "sending mp4 to client";
+
+    if (clcf->directio <= of.size) {
+
+        /*
+         * DIRECTIO is set on transfer only
+         * to allow kernel to cache "moov" atom
+         */
+
+        if (ngx_directio_on(of.fd) == NGX_FILE_ERROR) {
+            ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
+                          ngx_directio_on_n " \"%s\" failed", path.data);
+        }
+
+        of.is_directio = 1;
+
+        if (mp4) {
+            mp4->file.directio = 1;
+        }
+    }
+
+    r->headers_out.status = NGX_HTTP_OK;
+    r->headers_out.last_modified_time = of.mtime;
+
+    if (ngx_http_set_content_type(r) != NGX_OK) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    if (mp4 == NULL) {
+        b = ngx_pcalloc(r->pool, sizeof(ngx_buf_t));
+        if (b == NULL) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+
+        b->file = ngx_pcalloc(r->pool, sizeof(ngx_file_t));
+        if (b->file == NULL) {
+            return NGX_HTTP_INTERNAL_SERVER_ERROR;
+        }
+    }
+
+    rc = ngx_http_send_header(r);
+
+    if (rc == NGX_ERROR || rc > NGX_OK || r->header_only) {
+        return rc;
+    }
+
+    if (mp4) {
+        return ngx_http_output_filter(r, mp4->out);
+    }
+
+    b->file_pos = 0;
+    b->file_last = of.size;
+
+    b->in_file = b->file_last ? 1 : 0;
+    b->last_buf = 1;
+    b->last_in_chain = 1;
+
+    b->file->fd = of.fd;
+    b->file->name = path;
+    b->file->log = log;
+    b->file->directio = of.is_directio;
+
+    out.buf = b;
+    out.next = NULL;
+
+    return ngx_http_output_filter(r, &out);
+}
+
+
+static ngx_int_t
+ngx_http_mp4_process(ngx_http_mp4_file_t *mp4)
+{
+    off_t                  start_offset, adjustment;
+    ngx_int_t              rc;
+    ngx_uint_t             i, j;
+    ngx_chain_t          **prev;
+    ngx_http_mp4_trak_t   *trak;
+    ngx_http_mp4_conf_t   *conf;
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 start:%ui", mp4->start);
+
+    conf = ngx_http_get_module_loc_conf(mp4->request, ngx_http_mp4_module);
+
+    mp4->buffer_size = conf->buffer_size;
+
+    rc = ngx_http_mp4_read_atom(mp4, ngx_http_mp4_atoms, mp4->end);
+    if (rc != NGX_OK) {
+        return rc;
+    }
+
+    if (mp4->trak.nelts == 0) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "no mp4 trak atoms were found in \"%s\"",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    if (mp4->mdat_atom.buf == NULL) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "no mp4 mdat atom was found in \"%s\"",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    prev = &mp4->out;
+
+    if (mp4->ftyp_atom.buf) {
+        *prev = &mp4->ftyp_atom;
+        prev = &mp4->ftyp_atom.next;
+    }
+
+    *prev = &mp4->moov_atom;
+    prev = &mp4->moov_atom.next;
+
+    if (mp4->mvhd_atom.buf) {
+        mp4->moov_size += mp4->mvhd_atom_buf.last - mp4->mvhd_atom_buf.pos;
+        *prev = &mp4->mvhd_atom;
+        prev = &mp4->mvhd_atom.next;
+    }
+
+    start_offset = mp4->end;
+    trak = mp4->trak.elts;
+
+    for (i = 0; i < mp4->trak.nelts; i++) {
+
+        if (ngx_http_mp4_update_stts_atom(mp4, &trak[i]) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        if (ngx_http_mp4_update_stss_atom(mp4, &trak[i]) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        ngx_http_mp4_update_ctts_atom(mp4, &trak[i]);
+
+        if (ngx_http_mp4_update_stsc_atom(mp4, &trak[i]) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        ngx_http_mp4_update_stsz_atom(mp4, &trak[i]);
+
+        if (ngx_http_mp4_update_stco_atom(mp4, &trak[i]) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        ngx_http_mp4_update_stbl_atom(mp4, &trak[i]);
+        ngx_http_mp4_update_minf_atom(mp4, &trak[i]);
+        trak[i].size += trak[i].mdhd_size;
+        trak[i].size += trak[i].hdlr_size;
+        ngx_http_mp4_update_mdia_atom(mp4, &trak[i]);
+        trak[i].size += trak[i].tkhd_size;
+        ngx_http_mp4_update_trak_atom(mp4, &trak[i]);
+
+        mp4->moov_size += trak[i].size;
+
+        if (start_offset > trak[i].start_offset) {
+            start_offset = trak[i].start_offset;
+        }
+
+        *prev = &trak[i].out[NGX_HTTP_MP4_TRAK_ATOM];
+        prev = &trak[i].out[NGX_HTTP_MP4_TRAK_ATOM].next;
+
+        for (j = 0; j < NGX_HTTP_MP4_LAST_ATOM + 1; j++) {
+            if (trak[i].out[j].buf) {
+                *prev = &trak[i].out[j];
+                prev = &trak[i].out[j].next;
+            }
+        }
+    }
+
+    mp4->moov_size += 8;
+
+    ngx_mp4_set_32value(mp4->moov_atom_header, mp4->moov_size);
+    ngx_mp4_set_atom_name(mp4->moov_atom_header, 'm', 'o', 'o', 'v');
+    mp4->content_length += mp4->moov_size;
+
+    *prev = &mp4->mdat_atom;
+
+    adjustment = mp4->ftyp_size + mp4->moov_size
+                 + ngx_http_mp4_update_mdat_atom(mp4, start_offset)
+                 - start_offset;
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 adjustment:%D", adjustment);
+
+    for (i = 0; i < mp4->trak.nelts; i++) {
+        ngx_http_mp4_adjust_stco_atom(mp4, &trak[i], (int32_t) adjustment);
+    }
+
+    return NGX_OK;
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+} ngx_mp4_atom_header_t;
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    size64[8];
+} ngx_mp4_atom_header64_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_atom_handler_t *atom, uint64_t atom_data_size)
+{
+    off_t        end;
+    size_t       atom_header_size;
+    u_char      *atom_header, *atom_name;
+    uint64_t     atom_size;
+    ngx_int_t    rc;
+    ngx_uint_t   n;
+
+    end = mp4->offset + atom_data_size;
+
+    while (mp4->offset < end) {
+
+        if (mp4->buffer_pos + sizeof(uint32_t) > mp4->buffer_end) {
+            if (ngx_http_mp4_read(mp4) != NGX_OK) {
+                return NGX_ERROR;
+            }
+        }
+
+        atom_header = mp4->buffer_pos;
+        atom_size = ngx_mp4_get_32value(atom_header);
+        atom_header_size = sizeof(ngx_mp4_atom_header_t);
+
+        if (atom_size == 0) {
+            ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                           "mp4 atom end");
+            return NGX_OK;
+        }
+
+        if (atom_size < sizeof(ngx_mp4_atom_header_t)) {
+
+            if (atom_size == 1) {
+
+                if (mp4->buffer_pos + sizeof(ngx_mp4_atom_header64_t)
+                    > mp4->buffer_end)
+                {
+                    if (ngx_http_mp4_read(mp4) != NGX_OK) {
+                        return NGX_ERROR;
+                    }
+
+                    atom_header = mp4->buffer_pos;
+                }
+
+                /* 64-bit atom size */
+                atom_size = ngx_mp4_get_64value(atom_header + 8);
+                atom_header_size = sizeof(ngx_mp4_atom_header64_t);
+
+            } else {
+                ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                              "\"%s\" mp4 atom is too small:%uL",
+                              mp4->file.name.data, atom_size);
+                return NGX_ERROR;
+            }
+        }
+
+        if (mp4->buffer_pos + sizeof(ngx_mp4_atom_header_t) > mp4->buffer_end) {
+            if (ngx_http_mp4_read(mp4) != NGX_OK) {
+                return NGX_ERROR;
+            }
+
+            atom_header = mp4->buffer_pos;
+        }
+
+        atom_name = atom_header + sizeof(uint32_t);
+
+        ngx_log_debug4(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                       "mp4 atom: %*s @%O:%uL",
+                       4, atom_name, mp4->offset, atom_size);
+
+        for (n = 0; atom[n].name; n++) {
+
+            if (ngx_strncmp(atom_name, atom[n].name, 4) == 0) {
+
+                ngx_mp4_atom_next(mp4, atom_header_size);
+
+                rc = atom[n].handler(mp4, atom_size - atom_header_size);
+                if (rc != NGX_OK) {
+                    return rc;
+                }
+
+                goto next;
+            }
+        }
+
+        ngx_mp4_atom_next(mp4, atom_size);
+
+    next:
+        continue;
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read(ngx_http_mp4_file_t *mp4)
+{
+    ngx_int_t  n;
+
+    if (mp4->offset + (off_t) mp4->buffer_size > mp4->end) {
+        mp4->buffer_size = (size_t) (mp4->end - mp4->offset);
+    }
+
+    if (mp4->buffer == NULL) {
+        mp4->buffer = ngx_palloc(mp4->request->pool, mp4->buffer_size);
+        if (mp4->buffer == NULL) {
+            return NGX_ERROR;
+        }
+
+        mp4->buffer_start = mp4->buffer;
+        mp4->buffer_end = mp4->buffer + mp4->buffer_size;
+    }
+
+    n = ngx_read_file(&mp4->file, mp4->buffer_start, mp4->buffer_size,
+                      mp4->offset);
+
+    if (n == NGX_ERROR) {
+        return NGX_ERROR;
+    }
+
+    if (n == 0) {
+        return NGX_OK;
+    }
+
+    mp4->buffer_pos = mp4->buffer_start;
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_ftyp_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char     *ftyp_atom;
+    size_t      atom_size;
+    ngx_buf_t  *atom;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 ftyp atom");
+
+    if (atom_data_size > 1024) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "\"%s\" mp4 ftyp atom is too large:%uL",
+                      mp4->file.name.data, atom_data_size);
+        return NGX_ERROR;
+    }
+
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+
+    ftyp_atom = ngx_palloc(mp4->request->pool, atom_size);
+    if (ftyp_atom == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_mp4_set_32value(ftyp_atom, atom_size);
+    ngx_mp4_set_atom_name(ftyp_atom, 'f', 't', 'y', 'p');
+
+    /*
+     * only moov atom content is guaranteed to be in mp4->buffer
+     * during sending response, so ftyp atom content should be copied
+     */
+    ngx_memcpy(ftyp_atom + sizeof(ngx_mp4_atom_header_t),
+               ngx_mp4_atom_data(mp4), (size_t) atom_data_size);
+
+    atom = &mp4->ftyp_atom_buf;
+    atom->temporary = 1;
+    atom->pos = ftyp_atom;
+    atom->last = ftyp_atom + atom_size;
+
+    mp4->ftyp_atom.buf = atom;
+    mp4->ftyp_size = atom_size;
+    mp4->content_length = atom_size;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+/*
+ * Small excess buffer to process atoms after moov atom, mp4->buffer_start
+ * will be set to this buffer part after moov atom processing.
+ */
+#define NGX_HTTP_MP4_MOOV_BUFFER_EXCESS  (4 * 1024)
+
+static ngx_int_t
+ngx_http_mp4_read_moov_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    ngx_int_t             rc;
+    ngx_uint_t            no_mdat;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_conf_t  *conf;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 moov atom");
+
+    no_mdat = (mp4->mdat_atom.buf == NULL);
+
+    if (no_mdat && mp4->start == 0) {
+        /*
+         * send original file if moov atom resides before
+         * mdat atom and client requests integral file
+         */
+        return NGX_DECLINED;
+    }
+
+    conf = ngx_http_get_module_loc_conf(mp4->request, ngx_http_mp4_module);
+
+    if (atom_data_size > mp4->buffer_size) {
+
+        if (atom_data_size > conf->max_buffer_size) {
+            ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                          "\"%s\" mp4 moov atom is too large:%uL, "
+                          "you may want to increase mp4_max_buffer_size",
+                          mp4->file.name.data, atom_data_size);
+            return NGX_ERROR;
+        }
+
+        ngx_pfree(mp4->request->pool, mp4->buffer);
+        mp4->buffer = NULL;
+        mp4->buffer_pos = NULL;
+        mp4->buffer_end = NULL;
+
+        mp4->buffer_size = (size_t) atom_data_size
+                         + NGX_HTTP_MP4_MOOV_BUFFER_EXCESS * no_mdat;
+    }
+
+    mp4->trak.elts = &mp4->traks;
+    mp4->trak.size = sizeof(ngx_http_mp4_trak_t);
+    mp4->trak.nalloc = 2;
+    mp4->trak.pool = mp4->request->pool;
+
+    atom = &mp4->moov_atom_buf;
+    atom->temporary = 1;
+    atom->pos = mp4->moov_atom_header;
+    atom->last = mp4->moov_atom_header + 8;
+
+    mp4->moov_atom.buf = &mp4->moov_atom_buf;
+
+    rc = ngx_http_mp4_read_atom(mp4, ngx_http_mp4_moov_atoms, atom_data_size);
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 moov atom done");
+
+    if (no_mdat) {
+        mp4->buffer_start = mp4->buffer_pos;
+        mp4->buffer_size = NGX_HTTP_MP4_MOOV_BUFFER_EXCESS;
+
+    } else {
+        /* skip atoms after moov atom */
+        mp4->offset = mp4->end;
+    }
+
+    return rc;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_mdat_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    ngx_buf_t  *data;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 mdat atom");
+
+    data = &mp4->mdat_data_buf;
+    data->file = &mp4->file;
+    data->in_file = 1;
+    data->last_buf = 1;
+    data->last_in_chain = 1;
+    data->file_last = mp4->offset + atom_data_size;
+
+    mp4->mdat_atom.buf = &mp4->mdat_atom_buf;
+    mp4->mdat_atom.next = &mp4->mdat_data;
+    mp4->mdat_data.buf = data;
+
+    if (mp4->trak.nelts) {
+        /* skip atoms after mdat atom */
+        mp4->offset = mp4->end;
+
+    } else {
+        ngx_mp4_atom_next(mp4, atom_data_size);
+    }
+
+    return NGX_OK;
+}
+
+
+static size_t
+ngx_http_mp4_update_mdat_atom(ngx_http_mp4_file_t *mp4, off_t start_offset)
+{
+    off_t       atom_data_size;
+    u_char     *atom_header;
+    uint32_t    atom_header_size;
+    uint64_t    atom_size;
+    ngx_buf_t  *atom;
+
+    atom_data_size = mp4->mdat_data.buf->file_last - start_offset;
+    mp4->mdat_data.buf->file_pos = start_offset;
+    mp4->content_length += atom_data_size;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mdat new offset @%O:%O", start_offset, atom_data_size);
+
+    atom_header = mp4->mdat_atom_header;
+
+    if (atom_data_size > 0xffffffff) {
+        atom_size = 1;
+        atom_header_size = sizeof(ngx_mp4_atom_header64_t);
+        ngx_mp4_set_64value(atom_header + sizeof(ngx_mp4_atom_header_t),
+                            sizeof(ngx_mp4_atom_header64_t) + atom_data_size);
+    } else {
+        atom_size = sizeof(ngx_mp4_atom_header_t) + atom_data_size;
+        atom_header_size = sizeof(ngx_mp4_atom_header_t);
+    }
+
+    ngx_mp4_set_32value(atom_header, atom_size);
+    ngx_mp4_set_atom_name(atom_header, 'm', 'd', 'a', 't');
+
+    atom = &mp4->mdat_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + atom_header_size;
+
+    return atom_header_size;
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    creation_time[4];
+    u_char    modification_time[4];
+    u_char    timescale[4];
+    u_char    duration[4];
+    u_char    rate[4];
+    u_char    volume[2];
+    u_char    reserved[10];
+    u_char    matrix[36];
+    u_char    preview_time[4];
+    u_char    preview_duration[4];
+    u_char    poster_time[4];
+    u_char    selection_time[4];
+    u_char    selection_duration[4];
+    u_char    current_time[4];
+    u_char    next_track_id[4];
+} ngx_mp4_mvhd_atom_t;
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    creation_time[8];
+    u_char    modification_time[8];
+    u_char    timescale[4];
+    u_char    duration[8];
+    u_char    rate[4];
+    u_char    volume[2];
+    u_char    reserved[10];
+    u_char    matrix[36];
+    u_char    preview_time[4];
+    u_char    preview_duration[4];
+    u_char    poster_time[4];
+    u_char    selection_time[4];
+    u_char    selection_duration[4];
+    u_char    current_time[4];
+    u_char    next_track_id[4];
+} ngx_mp4_mvhd64_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_mvhd_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char                 *atom_header;
+    size_t                  atom_size;
+    uint32_t                timescale;
+    uint64_t                duration;
+    ngx_buf_t              *atom;
+    ngx_mp4_mvhd_atom_t    *mvhd_atom;
+    ngx_mp4_mvhd64_atom_t  *mvhd64_atom;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 mvhd atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    mvhd_atom = (ngx_mp4_mvhd_atom_t *) atom_header;
+    mvhd64_atom = (ngx_mp4_mvhd64_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(atom_header, 'm', 'v', 'h', 'd');
+
+    if (mvhd_atom->version[0] == 0) {
+        /* version 0: 32-bit duration */
+        timescale = ngx_mp4_get_32value(mvhd_atom->timescale);
+        duration = ngx_mp4_get_32value(mvhd_atom->duration);
+
+    } else {
+        /* version 1: 64-bit duration */
+        timescale = ngx_mp4_get_32value(mvhd64_atom->timescale);
+        duration = ngx_mp4_get_64value(mvhd64_atom->duration);
+    }
+
+    mp4->timescale = timescale;
+
+    ngx_log_debug3(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mvhd timescale:%uD, duration:%uL, time:%.3fs",
+                   timescale, duration, (double) duration / timescale);
+
+    duration -= (uint64_t) mp4->start * timescale / 1000;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mvhd new duration:%uL, time:%.3fs",
+                   duration, (double) duration / timescale);
+
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+    ngx_mp4_set_32value(mvhd_atom->size, atom_size);
+
+    if (mvhd_atom->version[0] == 0) {
+        ngx_mp4_set_32value(mvhd_atom->duration, duration);
+
+    } else {
+        ngx_mp4_set_64value(mvhd64_atom->duration, duration);
+    }
+
+    atom = &mp4->mvhd_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + atom_size;
+
+    mp4->mvhd_atom.buf = atom;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_trak_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header, *atom_end;
+    off_t                 atom_file_end;
+    ngx_int_t             rc;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 trak atom");
+
+    trak = ngx_array_push(&mp4->trak);
+    if (trak == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_memzero(trak, sizeof(ngx_http_mp4_trak_t));
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    ngx_mp4_set_atom_name(atom_header, 't', 'r', 'a', 'k');
+
+    atom = &trak->trak_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + sizeof(ngx_mp4_atom_header_t);
+
+    trak->out[NGX_HTTP_MP4_TRAK_ATOM].buf = atom;
+
+    atom_end = mp4->buffer_pos + atom_data_size;
+    atom_file_end = mp4->offset + atom_data_size;
+
+    rc = ngx_http_mp4_read_atom(mp4, ngx_http_mp4_trak_atoms, atom_data_size);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 trak atom: %i", rc);
+
+    if (rc == NGX_DECLINED) {
+        /* skip this trak */
+        ngx_memzero(trak, sizeof(ngx_http_mp4_trak_t));
+        mp4->trak.nelts--;
+        mp4->buffer_pos = atom_end;
+        mp4->offset = atom_file_end;
+        return NGX_OK;
+    }
+
+    return rc;
+}
+
+
+static void
+ngx_http_mp4_update_trak_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    ngx_buf_t  *atom;
+
+    trak->size += sizeof(ngx_mp4_atom_header_t);
+    atom = &trak->trak_atom_buf;
+    ngx_mp4_set_32value(atom->pos, trak->size);
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_cmov_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                  "\"%s\" mp4 compressed moov atom (cmov) is not supported",
+                  mp4->file.name.data);
+
+    return NGX_ERROR;
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    creation_time[4];
+    u_char    modification_time[4];
+    u_char    track_id[4];
+    u_char    reserved1[4];
+    u_char    duration[4];
+    u_char    reserved2[8];
+    u_char    layer[2];
+    u_char    group[2];
+    u_char    volume[2];
+    u_char    reverved3[2];
+    u_char    matrix[36];
+    u_char    width[4];
+    u_char    heigth[4];
+} ngx_mp4_tkhd_atom_t;
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    creation_time[8];
+    u_char    modification_time[8];
+    u_char    track_id[4];
+    u_char    reserved1[4];
+    u_char    duration[8];
+    u_char    reserved2[8];
+    u_char    layer[2];
+    u_char    group[2];
+    u_char    volume[2];
+    u_char    reverved3[2];
+    u_char    matrix[36];
+    u_char    width[4];
+    u_char    heigth[4];
+} ngx_mp4_tkhd64_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_tkhd_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char                 *atom_header;
+    size_t                  atom_size;
+    uint64_t                duration;
+    ngx_buf_t              *atom;
+    ngx_http_mp4_trak_t    *trak;
+    ngx_mp4_tkhd_atom_t    *tkhd_atom;
+    ngx_mp4_tkhd64_atom_t  *tkhd64_atom;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 tkhd atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    tkhd_atom = (ngx_mp4_tkhd_atom_t *) atom_header;
+    tkhd64_atom = (ngx_mp4_tkhd64_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(tkhd_atom, 't', 'k', 'h', 'd');
+
+    if (tkhd_atom->version[0] == 0) {
+        /* version 0: 32-bit duration */
+        duration = ngx_mp4_get_32value(tkhd_atom->duration);
+
+    } else {
+        /* version 1: 64-bit duration */
+        duration = ngx_mp4_get_64value(tkhd64_atom->duration);
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "tkhd duration:%uL, time:%.3fs",
+                   duration, (double) duration / mp4->timescale);
+
+    duration -= (uint64_t) mp4->start * mp4->timescale / 1000;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "tkhd new duration:%uL, time:%.3fs",
+                   duration, (double) duration / mp4->timescale);
+
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->tkhd_size = atom_size;
+
+    ngx_mp4_set_32value(tkhd_atom->size, atom_size);
+
+    if (tkhd_atom->version[0] == 0) {
+        ngx_mp4_set_32value(tkhd_atom->duration, duration);
+
+    } else {
+        ngx_mp4_set_64value(tkhd64_atom->duration, duration);
+    }
+
+    atom = &trak->tkhd_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + atom_size;
+
+    trak->out[NGX_HTTP_MP4_TKHD_ATOM].buf = atom;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_mdia_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "process mdia atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    ngx_mp4_set_atom_name(atom_header, 'm', 'd', 'i', 'a');
+
+    trak = ngx_mp4_last_trak(mp4);
+
+    atom = &trak->mdia_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + sizeof(ngx_mp4_atom_header_t);
+
+    trak->out[NGX_HTTP_MP4_MDIA_ATOM].buf = atom;
+
+    return ngx_http_mp4_read_atom(mp4, ngx_http_mp4_mdia_atoms, atom_data_size);
+}
+
+
+static void
+ngx_http_mp4_update_mdia_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    ngx_buf_t  *atom;
+
+    trak->size += sizeof(ngx_mp4_atom_header_t);
+    atom = &trak->mdia_atom_buf;
+    ngx_mp4_set_32value(atom->pos, trak->size);
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    creation_time[4];
+    u_char    modification_time[4];
+    u_char    timescale[4];
+    u_char    duration[4];
+    u_char    language[2];
+    u_char    quality[2];
+} ngx_mp4_mdhd_atom_t;
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    creation_time[8];
+    u_char    modification_time[8];
+    u_char    timescale[4];
+    u_char    duration[8];
+    u_char    language[2];
+    u_char    quality[2];
+} ngx_mp4_mdhd64_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_mdhd_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char                 *atom_header;
+    size_t                  atom_size;
+    uint32_t                timescale;
+    uint64_t                duration;
+    ngx_buf_t              *atom;
+    ngx_http_mp4_trak_t    *trak;
+    ngx_mp4_mdhd_atom_t    *mdhd_atom;
+    ngx_mp4_mdhd64_atom_t  *mdhd64_atom;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 mdhd atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    mdhd_atom = (ngx_mp4_mdhd_atom_t *) atom_header;
+    mdhd64_atom = (ngx_mp4_mdhd64_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(mdhd_atom, 'm', 'd', 'h', 'd');
+
+    if (mdhd_atom->version[0] == 0) {
+        /* version 0: everything is 32-bit */
+        timescale = ngx_mp4_get_32value(mdhd_atom->timescale);
+        duration = ngx_mp4_get_32value(mdhd_atom->duration);
+
+    } else {
+        /* version 1: 64-bit duration and 32-bit timescale */
+        timescale = ngx_mp4_get_32value(mdhd64_atom->timescale);
+        duration = ngx_mp4_get_64value(mdhd64_atom->duration);
+    }
+
+    ngx_log_debug3(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mdhd timescale:%uD, duration:%uL, time:%.3fs",
+                   timescale, duration, (double) duration / timescale);
+
+    duration -= (uint64_t) mp4->start * timescale / 1000;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mdhd new duration:%uL, time:%.3fs",
+                   duration, (double) duration / timescale);
+
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->mdhd_size = atom_size;
+    trak->timescale = timescale;
+
+    ngx_mp4_set_32value(mdhd_atom->size, atom_size);
+
+    if (mdhd_atom->version[0] == 0) {
+        ngx_mp4_set_32value(mdhd_atom->duration, duration);
+
+    } else {
+        ngx_mp4_set_64value(mdhd64_atom->duration, duration);
+    }
+
+    atom = &trak->mdhd_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + atom_size;
+
+    trak->out[NGX_HTTP_MP4_MDHD_ATOM].buf = atom;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_hdlr_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char              *atom_header;
+    size_t               atom_size;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 hdlr atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+    ngx_mp4_set_32value(atom_header, atom_size);
+    ngx_mp4_set_atom_name(atom_header, 'h', 'd', 'l', 'r');
+
+    trak = ngx_mp4_last_trak(mp4);
+
+    atom = &trak->hdlr_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + atom_size;
+
+    trak->hdlr_size = atom_size;
+    trak->out[NGX_HTTP_MP4_HDLR_ATOM].buf = atom;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_minf_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "process minf atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    ngx_mp4_set_atom_name(atom_header, 'm', 'i', 'n', 'f');
+
+    trak = ngx_mp4_last_trak(mp4);
+
+    atom = &trak->minf_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + sizeof(ngx_mp4_atom_header_t);
+
+    trak->out[NGX_HTTP_MP4_MINF_ATOM].buf = atom;
+
+    return ngx_http_mp4_read_atom(mp4, ngx_http_mp4_minf_atoms, atom_data_size);
+}
+
+
+static void
+ngx_http_mp4_update_minf_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    ngx_buf_t  *atom;
+
+    trak->size += sizeof(ngx_mp4_atom_header_t)
+               + trak->vmhd_size
+               + trak->smhd_size
+               + trak->dinf_size;
+    atom = &trak->minf_atom_buf;
+    ngx_mp4_set_32value(atom->pos, trak->size);
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_vmhd_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char              *atom_header;
+    size_t               atom_size;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 vmhd atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+    ngx_mp4_set_32value(atom_header, atom_size);
+    ngx_mp4_set_atom_name(atom_header, 'v', 'm', 'h', 'd');
+
+    trak = ngx_mp4_last_trak(mp4);
+
+    atom = &trak->vmhd_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + atom_size;
+
+    trak->vmhd_size += atom_size;
+    trak->out[NGX_HTTP_MP4_VMHD_ATOM].buf = atom;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_smhd_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char              *atom_header;
+    size_t               atom_size;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 smhd atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+    ngx_mp4_set_32value(atom_header, atom_size);
+    ngx_mp4_set_atom_name(atom_header, 's', 'm', 'h', 'd');
+
+    trak = ngx_mp4_last_trak(mp4);
+
+    atom = &trak->smhd_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + atom_size;
+
+    trak->vmhd_size += atom_size;
+    trak->out[NGX_HTTP_MP4_SMHD_ATOM].buf = atom;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_dinf_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char              *atom_header;
+    size_t               atom_size;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 dinf atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+    ngx_mp4_set_32value(atom_header, atom_size);
+    ngx_mp4_set_atom_name(atom_header, 'd', 'i', 'n', 'f');
+
+    trak = ngx_mp4_last_trak(mp4);
+
+    atom = &trak->dinf_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + atom_size;
+
+    trak->dinf_size += atom_size;
+    trak->out[NGX_HTTP_MP4_DINF_ATOM].buf = atom;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_read_stbl_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header;
+    ngx_buf_t            *atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "process stbl atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    ngx_mp4_set_atom_name(atom_header, 's', 't', 'b', 'l');
+
+    trak = ngx_mp4_last_trak(mp4);
+
+    atom = &trak->stbl_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_header + sizeof(ngx_mp4_atom_header_t);
+
+    trak->out[NGX_HTTP_MP4_STBL_ATOM].buf = atom;
+
+    return ngx_http_mp4_read_atom(mp4, ngx_http_mp4_stbl_atoms, atom_data_size);
+}
+
+
+static void
+ngx_http_mp4_update_stbl_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    ngx_buf_t  *atom;
+
+    trak->size += sizeof(ngx_mp4_atom_header_t);
+    atom = &trak->stbl_atom_buf;
+    ngx_mp4_set_32value(atom->pos, trak->size);
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    entries[4];
+
+    u_char    media_size[4];
+    u_char    media_name[4];
+} ngx_mp4_stsd_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_stsd_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header, *atom_table;
+    size_t                atom_size;
+    uint32_t              entries;
+    ngx_buf_t            *atom;
+    ngx_mp4_stsd_atom_t  *stsd_atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    /* sample description atom */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 stsd atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    stsd_atom = (ngx_mp4_stsd_atom_t *) atom_header;
+    atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+    atom_table = atom_header + atom_size;
+    ngx_mp4_set_32value(stsd_atom->size, atom_size);
+    ngx_mp4_set_atom_name(stsd_atom, 's', 't', 's', 'd');
+
+    entries = ngx_mp4_get_32value(stsd_atom->entries);
+
+    if ((uint64_t) (sizeof(ngx_mp4_stsd_atom_t) - sizeof(ngx_mp4_atom_header_t))
+         > atom_data_size) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "\"%s\" mp4 stsd atom too large",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    ngx_log_debug3(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "stsd entries:%uD, media:%*s",
+                   ngx_mp4_get_32value(stsd_atom->entries),
+                   4, stsd_atom->media_name);
+
+    /* supported media format: "avc1" (H.264) and "mp4a" (MPEG-4/AAC) */
+
+    if (ngx_strncmp(stsd_atom->media_name, "avc1", 4) != 0
+        && ngx_strncmp(stsd_atom->media_name, "mp4a", 4) != 0)
+    {
+        return NGX_DECLINED;
+    }
+
+    trak = ngx_mp4_last_trak(mp4);
+
+    atom = &trak->stsd_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_table;
+
+    trak->out[NGX_HTTP_MP4_STSD_ATOM].buf = atom;
+    trak->size += atom_size;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    entries[4];
+} ngx_mp4_stts_atom_t;
+
+typedef struct {
+    u_char    count[4];
+    u_char    duration[4];
+} ngx_mp4_stts_entry_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_stts_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header, *atom_table, *atom_end;
+    uint32_t              entries;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_stts_atom_t  *stts_atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    /* time-to-sample atom */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 stts atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    stts_atom = (ngx_mp4_stts_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(stts_atom, 's', 't', 't', 's');
+
+    entries = ngx_mp4_get_32value(stts_atom->entries);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 time-to-sample entries:%uD", entries);
+
+    atom_table = atom_header + sizeof(ngx_mp4_stts_atom_t);
+    atom_end = atom_table + entries * sizeof(ngx_mp4_stts_entry_t);
+
+    if ((uint64_t) (atom_end - stts_atom->version) > atom_data_size) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "\"%s\" mp4 stts atom too large",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->time_to_sample_entries = entries;
+
+    atom = &trak->stts_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_table;
+
+    data = &trak->stts_data_buf;
+    data->temporary = 1;
+    data->pos = atom_table;
+    data->last = atom_end;
+
+    trak->out[NGX_HTTP_MP4_STTS_ATOM].buf = atom;
+    trak->out[NGX_HTTP_MP4_STTS_DATA].buf = data;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_update_stts_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    size_t                 atom_size;
+    uint32_t               entries, count, duration;
+    uint64_t               start_time;
+    ngx_buf_t             *atom, *data;
+    ngx_uint_t             start_sample;
+    ngx_mp4_stts_atom_t   *stts_atom;
+    ngx_mp4_stts_entry_t  *entry, *end;
+
+    /*
+     * mdia.minf.stbl.stts updating requires trak->timescale
+     * from mdia.mdhd atom which may reside after mdia.minf
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 stts atom update");
+
+    data = trak->out[NGX_HTTP_MP4_STTS_DATA].buf;
+
+    if (data == NULL) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "no mp4 stts atoms were found in \"%s\"",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    entries = trak->time_to_sample_entries;
+    start_time = mp4->start * trak->timescale / 1000;
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "time-to-sample start_time:%uL", start_time);
+
+    start_sample = 0;
+    entry = (ngx_mp4_stts_entry_t *) data->pos;
+    end = (ngx_mp4_stts_entry_t *) data->last;
+
+    while (entry < end) {
+        count = ngx_mp4_get_32value(entry->count);
+        duration = ngx_mp4_get_32value(entry->duration);
+
+        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                       "count:%uD, duration:%uD", count, duration);
+
+        if (start_time < count * duration) {
+            start_sample += (ngx_uint_t) (start_time / duration);
+            count -= start_sample;
+            ngx_mp4_set_32value(entry->count, count);
+            goto found;
+        }
+
+        start_sample += count;
+        start_time -= count * duration;
+        entries--;
+        entry++;
+    }
+
+    ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                  "start time is out mp4 stts samples in \"%s\"",
+                  mp4->file.name.data);
+
+    return NGX_ERROR;
+
+found:
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "start_sample:%ui, new count:%uD", start_sample, count);
+
+    trak->start_sample = start_sample;
+
+    data->pos = (u_char *) entry;
+    atom_size = sizeof(ngx_mp4_stts_atom_t) + (data->last - data->pos);
+    trak->size += atom_size;
+
+    atom = trak->out[NGX_HTTP_MP4_STTS_ATOM].buf;
+    stts_atom = (ngx_mp4_stts_atom_t *) atom->pos;
+    ngx_mp4_set_32value(stts_atom->size, atom_size);
+    ngx_mp4_set_32value(stts_atom->entries, entries);
+
+    return NGX_OK;
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    entries[4];
+} ngx_http_mp4_stss_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_stss_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char                    *atom_header, *atom_table, *atom_end;
+    uint32_t                   entries;
+    ngx_buf_t                 *atom, *data;
+    ngx_http_mp4_trak_t       *trak;
+    ngx_http_mp4_stss_atom_t  *stss_atom;
+
+    /* sync samples atom */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 stss atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    stss_atom = (ngx_http_mp4_stss_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(stss_atom, 's', 't', 's', 's');
+
+    entries = ngx_mp4_get_32value(stss_atom->entries);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "sync sample entries:%uD", entries);
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->sync_samples_entries = entries;
+
+    atom_table = atom_header + sizeof(ngx_http_mp4_stss_atom_t);
+
+    atom = &trak->stss_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_table;
+
+    atom_end = atom_table + entries * sizeof(uint32_t);
+
+    if ((uint64_t) (atom_end - stss_atom->version) > atom_data_size) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "\"%s\" mp4 stss atom too large", mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    data = &trak->stss_data_buf;
+    data->temporary = 1;
+    data->pos = atom_table;
+    data->last = atom_end;
+
+    trak->out[NGX_HTTP_MP4_STSS_ATOM].buf = atom;
+    trak->out[NGX_HTTP_MP4_STSS_DATA].buf = data;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_update_stss_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    size_t                     atom_size;
+    uint32_t                   entries, sample, start_sample, *entry, *end;
+    ngx_buf_t                 *atom, *data;
+    ngx_http_mp4_stss_atom_t  *stss_atom;
+
+    /*
+     * mdia.minf.stbl.stss updating requires trak->start_sample
+     * from mdia.minf.stbl.stts which depends on value from mdia.mdhd
+     * atom which may reside after mdia.minf
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 stss atom update");
+
+    data = trak->out[NGX_HTTP_MP4_STSS_DATA].buf;
+
+    if (data == NULL) {
+        return NGX_OK;
+    }
+
+    /* sync samples starts from 1 */
+    start_sample = trak->start_sample + 1;
+    entries = trak->sync_samples_entries;
+
+    entry = (uint32_t *) data->pos;
+    end = (uint32_t *) data->last;
+
+    while (entry < end) {
+        sample = ngx_mp4_get_32value(entry);
+
+        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                       "start:%uD, sync:%uD", start_sample, sample);
+
+        if (sample >= start_sample) {
+            goto found;
+        }
+
+        entries--;
+        entry++;
+    }
+
+    ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                  "start sample is out of mp4 stss atom in \"%s\"",
+                  mp4->file.name.data);
+
+    return NGX_ERROR;
+
+found:
+
+    data->pos = (u_char *) entry;
+
+    start_sample = trak->start_sample;
+
+    while (entry < end) {
+        sample = ngx_mp4_get_32value(entry);
+        sample -= start_sample;
+        ngx_mp4_set_32value(entry, sample);
+        entry++;
+    }
+
+    atom_size = sizeof(ngx_http_mp4_stss_atom_t) + (data->last - data->pos);
+    trak->size += atom_size;
+
+    atom = trak->out[NGX_HTTP_MP4_STSS_ATOM].buf;
+    stss_atom = (ngx_http_mp4_stss_atom_t *) atom->pos;
+
+    ngx_mp4_set_32value(stss_atom->size, atom_size);
+    ngx_mp4_set_32value(stss_atom->entries, entries);
+
+    return NGX_OK;
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    entries[4];
+} ngx_mp4_ctts_atom_t;
+
+typedef struct {
+    u_char    count[4];
+    u_char    offset[4];
+} ngx_mp4_ctts_entry_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_ctts_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header, *atom_table, *atom_end;
+    uint32_t              entries;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_ctts_atom_t  *ctts_atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    /* composition offsets atom */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 ctts atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    ctts_atom = (ngx_mp4_ctts_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(ctts_atom, 'c', 't', 't', 's');
+
+    entries = ngx_mp4_get_32value(ctts_atom->entries);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "composition offset entries:%uD", entries);
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->composition_offset_entries = entries;
+
+    atom_table = atom_header + sizeof(ngx_mp4_ctts_atom_t);
+
+    atom = &trak->ctts_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_table;
+
+    atom_end = atom_table + entries * sizeof(ngx_mp4_ctts_entry_t);
+
+    if ((uint64_t) (atom_end - ctts_atom->version) > atom_data_size) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "\"%s\" mp4 ctts atom too large", mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    data = &trak->ctts_data_buf;
+    data->temporary = 1;
+    data->pos = atom_table;
+    data->last = atom_end;
+
+    trak->out[NGX_HTTP_MP4_CTTS_ATOM].buf = atom;
+    trak->out[NGX_HTTP_MP4_CTTS_DATA].buf = data;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static void
+ngx_http_mp4_update_ctts_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    size_t                 atom_size;
+    uint32_t               entries, count, start_sample;
+    ngx_buf_t             *atom, *data;
+    ngx_mp4_ctts_atom_t   *ctts_atom;
+    ngx_mp4_ctts_entry_t  *entry, *end;
+
+    /*
+     * mdia.minf.stbl.ctts updating requires trak->start_sample
+     * from mdia.minf.stbl.stts which depends on value from mdia.mdhd
+     * atom which may reside after mdia.minf
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 ctts atom update");
+
+    data = trak->out[NGX_HTTP_MP4_CTTS_DATA].buf;
+
+    if (data == NULL) {
+        return;
+    }
+
+    /* sync samples starts from 1 */
+    start_sample = trak->start_sample + 1;
+    entries = trak->composition_offset_entries;
+    entry = (ngx_mp4_ctts_entry_t *) data->pos;
+    end = (ngx_mp4_ctts_entry_t *) data->last;
+
+    while (entry < end) {
+        count = ngx_mp4_get_32value(entry->count);
+
+        ngx_log_debug3(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                       "start:%uD, count:%uD, offset:%uD",
+                       start_sample, count, ngx_mp4_get_32value(entry->offset));
+
+         if (start_sample <= count) {
+             count -= (start_sample - 1);
+             ngx_mp4_set_32value(entry->count, count);
+             goto found;
+         }
+
+         start_sample -= count;
+         entries--;
+         entry++;
+    }
+
+    trak->out[NGX_HTTP_MP4_CTTS_ATOM].buf = NULL;
+    trak->out[NGX_HTTP_MP4_CTTS_DATA].buf = NULL;
+
+    return;
+
+found:
+
+    data->pos = (u_char *) entry;
+    atom_size = sizeof(ngx_mp4_ctts_atom_t) + (data->last - data->pos);
+    trak->size += atom_size;
+
+    atom = trak->out[NGX_HTTP_MP4_CTTS_ATOM].buf;
+    ctts_atom = (ngx_mp4_ctts_atom_t *) atom->pos;
+
+    ngx_mp4_set_32value(ctts_atom->size, atom_size);
+    ngx_mp4_set_32value(ctts_atom->entries, entries);
+
+    return;
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    entries[4];
+} ngx_mp4_stsc_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_stsc_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header, *atom_table, *atom_end;
+    uint32_t              entries;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_stsc_atom_t  *stsc_atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    /* sample-to-chunk atom */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 stsc atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    stsc_atom = (ngx_mp4_stsc_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(stsc_atom, 's', 't', 's', 'c');
+
+    entries = ngx_mp4_get_32value(stsc_atom->entries);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "sample-to-chunk entries:%uD", entries);
+
+    atom_table = atom_header + sizeof(ngx_mp4_stsc_atom_t);
+    atom_end = atom_table + entries * sizeof(ngx_mp4_stsc_entry_t);
+
+    if ((uint64_t) (atom_end - stsc_atom->version) > atom_data_size) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "\"%s\" mp4 stsc atom too large",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->sample_to_chunk_entries = entries;
+
+    atom = &trak->stsc_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_table;
+
+    data = &trak->stsc_data_buf;
+    data->temporary = 1;
+    data->pos = atom_table;
+    data->last = atom_end;
+
+    trak->out[NGX_HTTP_MP4_STSC_ATOM].buf = atom;
+    trak->out[NGX_HTTP_MP4_STSC_DATA].buf = data;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_update_stsc_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    size_t                 atom_size;
+    uint32_t               start_sample, entries, chunk, samples, id,
+                           next_chunk, n;
+    ngx_buf_t             *atom, *data, *buf;
+    ngx_mp4_stsc_atom_t   *stsc_atom;
+    ngx_mp4_stsc_entry_t  *entry, *first, *end;
+
+    /*
+     * mdia.minf.stbl.stsc updating requires trak->start_sample
+     * from mdia.minf.stbl.stts which depends on value from mdia.mdhd
+     * atom which may reside after mdia.minf
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 stsc atom update");
+
+    data = trak->out[NGX_HTTP_MP4_STSC_DATA].buf;
+
+    if (data == NULL) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "no mp4 stsc atoms were found in \"%s\"",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    start_sample = (uint32_t) trak->start_sample;
+    entries = trak->sample_to_chunk_entries - 1;
+
+    entry = (ngx_mp4_stsc_entry_t *) data->pos;
+    end = (ngx_mp4_stsc_entry_t *) data->last;
+
+    chunk = ngx_mp4_get_32value(entry->chunk);
+    samples = ngx_mp4_get_32value(entry->samples);
+    id = ngx_mp4_get_32value(entry->id);
+    entry++;
+
+    while (entry < end) {
+
+        next_chunk = ngx_mp4_get_32value(entry->chunk);
+
+        ngx_log_debug5(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                       "start_sample:%uD, chunk:%uD, chunks:%uD, "
+                       "samples:%uD, id:%uD",
+                       start_sample, chunk, next_chunk - chunk, samples, id);
+
+        n = (next_chunk - chunk) * samples;
+
+        if (start_sample <= n) {
+            goto found;
+        }
+
+        start_sample -= n;
+
+        chunk = next_chunk;
+        samples = ngx_mp4_get_32value(entry->samples);
+        id = ngx_mp4_get_32value(entry->id);
+        entries--;
+        entry++;
+    }
+
+    next_chunk = trak->chunks;
+
+    ngx_log_debug4(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "start_sample:%uD, chunk:%uD, chunks:%uD, samples:%uD",
+                   start_sample, chunk, next_chunk - chunk, samples);
+
+    n = (next_chunk - chunk) * samples;
+
+    if (start_sample > n) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "start time is out mp4 stsc chunks in \"%s\"",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+found:
+
+    entries++;
+    entry--;
+
+    if (samples == 0) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "zero number of samples in \"%s\"",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    trak->start_chunk = chunk - 1;
+
+    trak->start_chunk += start_sample / samples;
+    trak->chunk_samples = start_sample % samples;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "start chunk:%ui, samples:%uD",
+                   trak->start_chunk, trak->chunk_samples);
+
+    data->pos = (u_char *) entry;
+    atom_size = sizeof(ngx_mp4_stsc_atom_t) + (data->last - data->pos);
+
+    if (trak->chunk_samples) {
+
+        first = &trak->stsc_chunk_entry;
+        ngx_mp4_set_32value(first->chunk, 1);
+        ngx_mp4_set_32value(first->samples, samples - trak->chunk_samples);
+        ngx_mp4_set_32value(first->id, id);
+
+        buf = &trak->stsc_chunk_buf;
+        buf->temporary = 1;
+        buf->pos = (u_char *) first;
+        buf->last = (u_char *) first + sizeof(ngx_mp4_stsc_entry_t);
+
+        trak->out[NGX_HTTP_MP4_STSC_CHUNK].buf = buf;
+
+        ngx_mp4_set_32value(entry->chunk, 2);
+
+        atom_size += sizeof(ngx_mp4_stsc_entry_t);
+    }
+
+    while (++entry < end) {
+        chunk = ngx_mp4_get_32value(entry->chunk);
+        chunk -= trak->start_chunk;
+        ngx_mp4_set_32value(entry->chunk, chunk);
+    }
+
+    trak->size += atom_size;
+
+    atom = trak->out[NGX_HTTP_MP4_STSC_ATOM].buf;
+    stsc_atom = (ngx_mp4_stsc_atom_t *) atom->pos;
+
+    ngx_mp4_set_32value(stsc_atom->size, atom_size);
+    ngx_mp4_set_32value(stsc_atom->entries, entries);
+
+    return NGX_OK;
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    uniform_size[4];
+    u_char    entries[4];
+} ngx_mp4_stsz_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_stsz_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header, *atom_table, *atom_end;
+    size_t                atom_size;
+    uint32_t              entries, size;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_stsz_atom_t  *stsz_atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    /* sample sizes atom */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 stsz atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    stsz_atom = (ngx_mp4_stsz_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(stsz_atom, 's', 't', 's', 'z');
+
+    size = ngx_mp4_get_32value(stsz_atom->uniform_size);
+    entries = ngx_mp4_get_32value(stsz_atom->entries);
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "sample uniform size:%uD, entries:%uD", size, entries);
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->sample_sizes_entries = entries;
+
+    atom_table = atom_header + sizeof(ngx_mp4_stsz_atom_t);
+
+    atom = &trak->stsz_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_table;
+
+    trak->out[NGX_HTTP_MP4_STSZ_ATOM].buf = atom;
+
+    if (size == 0) {
+        atom_end = atom_table + entries * sizeof(uint32_t);
+
+        if ((uint64_t) (atom_end - stsz_atom->version) > atom_data_size) {
+            ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                          "\"%s\" mp4 stsz atom too large",
+                          mp4->file.name.data);
+            return NGX_ERROR;
+        }
+
+        data = &trak->stsz_data_buf;
+        data->temporary = 1;
+        data->pos = atom_table;
+        data->last = atom_end;
+
+        trak->out[NGX_HTTP_MP4_STSZ_DATA].buf = data;
+
+    } else {
+        /* if size != 0 then all samples are the same size */
+        /* TODO : chunk samples */
+        atom_size = sizeof(ngx_mp4_atom_header_t) + (size_t) atom_data_size;
+        ngx_mp4_set_32value(atom_header, atom_size);
+        trak->size += atom_size;
+    }
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static void
+ngx_http_mp4_update_stsz_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    size_t                atom_size;
+    uint32_t             *pos, *end;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_stsz_atom_t  *stsz_atom;
+
+    /*
+     * mdia.minf.stbl.stsz updating requires trak->start_sample
+     * from mdia.minf.stbl.stts which depends on value from mdia.mdhd
+     * atom which may reside after mdia.minf
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 stsz atom update");
+
+    data = trak->out[NGX_HTTP_MP4_STSZ_DATA].buf;
+
+    if (data) {
+        data->pos += trak->start_sample * sizeof(uint32_t);
+        end = (uint32_t *) data->pos;
+
+        for (pos = end - trak->chunk_samples; pos < end; pos++) {
+            trak->chunk_samples_size += ngx_mp4_get_32value(pos);
+        }
+
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                       "chunk samples sizes:%uD", trak->chunk_samples_size);
+
+        atom_size = sizeof(ngx_mp4_stsz_atom_t) + (data->last - data->pos);
+        trak->size += atom_size;
+
+        atom = trak->out[NGX_HTTP_MP4_STSZ_ATOM].buf;
+        stsz_atom = (ngx_mp4_stsz_atom_t *) atom->pos;
+
+        ngx_mp4_set_32value(stsz_atom->size, atom_size);
+        ngx_mp4_set_32value(stsz_atom->entries,
+                            trak->sample_sizes_entries - trak->start_sample);
+    }
+}
+
+
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    entries[4];
+} ngx_mp4_stco_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_stco_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header, *atom_table, *atom_end;
+    uint32_t              entries;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_stco_atom_t  *stco_atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    /* chunk offsets atom */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 stco atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    stco_atom = (ngx_mp4_stco_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(stco_atom, 's', 't', 'c', 'o');
+
+    entries = ngx_mp4_get_32value(stco_atom->entries);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "chunks:%uD", entries);
+
+    atom_table = atom_header + sizeof(ngx_mp4_stco_atom_t);
+    atom_end = atom_table + entries * sizeof(uint32_t);
+
+    if ((uint64_t) (atom_end - stco_atom->version) > atom_data_size) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "\"%s\" mp4 stco atom too large", mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->chunks = entries;
+
+    atom = &trak->tsco_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_table;
+
+    data = &trak->tsco_data_buf;
+    data->temporary = 1;
+    data->pos = atom_table;
+    data->last = atom_end;
+
+    trak->out[NGX_HTTP_MP4_STCO_ATOM].buf = atom;
+    trak->out[NGX_HTTP_MP4_STCO_DATA].buf = data;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_update_stco_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    size_t                atom_size;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_stco_atom_t  *stco_atom;
+
+    /*
+     * mdia.minf.stbl.stco updating requires trak->start_chunk
+     * from mdia.minf.stbl.stsc which depends on value from mdia.mdhd
+     * atom which may reside after mdia.minf
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 stco atom update");
+
+    data = trak->out[NGX_HTTP_MP4_STCO_DATA].buf;
+
+    if (data == NULL) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "no mp4 stco atoms were found in \"%s\"",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    data->pos += trak->start_chunk * sizeof(uint32_t);
+    atom_size = sizeof(ngx_mp4_stco_atom_t) + (data->last - data->pos);
+    trak->size += atom_size;
+
+    trak->start_offset = ngx_mp4_get_32value(data->pos);
+    trak->start_offset += trak->chunk_samples_size;
+    ngx_mp4_set_32value(data->pos, trak->start_offset);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "start chunk offset:%uD", trak->start_offset);
+
+    atom = trak->out[NGX_HTTP_MP4_STCO_ATOM].buf;
+    stco_atom = (ngx_mp4_stco_atom_t *) atom->pos;
+
+    ngx_mp4_set_32value(stco_atom->size, atom_size);
+    ngx_mp4_set_32value(stco_atom->entries, trak->chunks - trak->start_chunk);
+
+    return NGX_OK;
+}
+
+
+static void
+ngx_http_mp4_adjust_stco_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak, int32_t adjustment)
+{
+    uint32_t    offset, *entry, *end;
+    ngx_buf_t  *data;
+
+    /*
+     * moov.trak.mdia.minf.stbl.stco adjustment requires
+     * minimal start offset of all traks and new moov atom size
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 stco atom adjustment");
+
+    data = trak->out[NGX_HTTP_MP4_STCO_DATA].buf;
+    entry = (uint32_t *) data->pos;
+    end = (uint32_t *) data->last;
+
+    while (entry < end) {
+        offset = ngx_mp4_get_32value(entry);
+        offset += adjustment;
+        ngx_mp4_set_32value(entry, offset);
+        entry++;
+    }
+}
+
+
+static char *
+ngx_http_mp4(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
+{
+    ngx_http_core_loc_conf_t  *clcf;
+
+    clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
+    clcf->handler = ngx_http_mp4_handler;
+
+    return NGX_CONF_OK;
+}
+
+
+static void *
+ngx_http_mp4_create_conf(ngx_conf_t *cf)
+{
+    ngx_http_mp4_conf_t  *conf;
+
+    conf = ngx_palloc(cf->pool, sizeof(ngx_http_mp4_conf_t));
+    if (conf == NULL) {
+        return NULL;
+    }
+
+    conf->buffer_size = NGX_CONF_UNSET_SIZE;
+    conf->max_buffer_size = NGX_CONF_UNSET_SIZE;
+
+    return conf;
+}
+
+
+static char *
+ngx_http_mp4_merge_conf(ngx_conf_t *cf, void *parent, void *child)
+{
+    ngx_http_mp4_conf_t *prev = parent;
+    ngx_http_mp4_conf_t *conf = child;
+
+    ngx_conf_merge_size_value(conf->buffer_size, prev->buffer_size, 512 * 1024);
+    ngx_conf_merge_size_value(conf->max_buffer_size, prev->max_buffer_size,
+                              10 * 1024 * 1024);
+
+    return NGX_CONF_OK;
+}