Mercurial > hg > nginx-site
annotate xml/en/docs/http/ngx_http_mp4_module.xml @ 583:90a5a62031ad
Added a forgotten link to ngx_http_index_module.
| author | Ruslan Ermilov <ru@nginx.com> |
|---|---|
| date | Wed, 11 Jul 2012 05:21:53 +0000 |
| parents | be54c443235a |
| children | 764fbac1b8b4 |
| rev | line source |
|---|---|
| 22 | 1 <?xml version="1.0"?> |
| 2 | |
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Added copyright markers to documentation sources.
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3 <!-- |
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4 Copyright (C) Nginx, Inc. |
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5 --> |
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6 |
| 22 | 7 <!DOCTYPE module SYSTEM "../../../../dtd/module.dtd"> |
| 8 | |
| 89 | 9 <module name="Module ngx_http_mp4_module" |
| 22 | 10 link="/en/docs/http/ngx_http_mp4_module.html" |
| 11 lang="en"> | |
| 12 | |
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Added proper support for anonymous sections, notably for the summary.
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13 <section id="summary"> |
| 22 | 14 |
| 15 <para> | |
| 271 | 16 The module <literal>ngx_http_mp4_module</literal> provides pseudo-streaming |
| 22 | 17 server-side support for H.264/AAC files typically having filename extensions |
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682163f2b298
Unified article/path and module/pathname into a single "path".
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18 <path>.mp4</path>, <path>.m4v</path>, and <path>.m4a</path>. |
| 22 | 19 </para> |
| 20 | |
| 21 <para> | |
| 88 | 22 Pseudo-streaming works in alliance with conforming Flash players. |
| 22 | 23 A player sends an HTTP request to the server with a start time |
| 24 argument in the request URI’s query string (named simply | |
| 271 | 25 <literal>start</literal> |
| 22 | 26 and specified in seconds), and the server responds with a stream |
| 27 so that its start position corresponds to the requested time, | |
| 28 for example: | |
| 29 <example> | |
| 30 http://example.com/elephants_dream.mp4?start=238.88 | |
| 31 </example> | |
| 32 This allows for a random seeking at any time, or starting playback | |
| 33 in the middle of a timeline. | |
| 34 </para> | |
| 35 | |
| 36 <para> | |
| 37 To support seeking, H.264-based formats store the metadata | |
| 38 in the so-called “moov atom.” | |
| 39 It is a part of the file that holds the index information for the | |
| 40 whole file. | |
| 41 </para> | |
| 42 | |
| 43 <para> | |
| 44 To start playback, a player first needs to read metadata. | |
| 45 This is done by sending a special request with the | |
| 271 | 46 <literal>start=0</literal> |
| 22 | 47 argument. Many encoding software will insert the metadata at |
| 48 the end of the file. This is bad for pseudo-streaming: | |
| 49 the metadata needs to be located at the beginning of the file, | |
| 50 or else the entire file will have to be downloaded before it | |
| 51 starts playing. If a file is well-formed (with metadata at the | |
| 52 beginning of a file), nginx just sends back the contents of a file. | |
| 53 Otherwise, it has to read the file and prepare a new stream so that | |
| 54 metadata comes before media data. | |
| 55 This involves some CPU, memory, and disk I/O overhead, | |
| 56 so it is a good idea to | |
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52
666e85596e3c
Added support for <link url="..."> which should eventually replace
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57 <link |
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666e85596e3c
Added support for <link url="..."> which should eventually replace
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58 url="http://flowplayer.org/plugins/streaming/pseudostreaming.html#prepare"> |
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666e85596e3c
Added support for <link url="..."> which should eventually replace
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59 prepare an original file for pseudo-streaming</link>, |
| 22 | 60 rather than having nginx do this on every such request. |
| 61 </para> | |
| 62 | |
| 63 <para> | |
| 64 For a matching request with a non-zero | |
| 271 | 65 <literal>start</literal> |
| 22 | 66 argument, nginx will read metadata from the file, prepare the |
| 67 stream starting from the requested offset, and send it to a client. | |
| 68 This has the same overhead as described above. | |
| 69 </para> | |
| 70 | |
| 71 <para> | |
| 72 If a matching request does not include the | |
| 271 | 73 <literal>start</literal> |
| 22 | 74 argument, there is no overhead, and the file is just sent as a static resource. |
| 75 Some players also support byte-range requests, and thus do not require | |
| 76 this module at all. | |
| 77 </para> | |
| 78 | |
| 79 <para> | |
| 80 This module is not built by default, it should be enabled with the | |
| 271 | 81 <literal>--with-http_mp4_module</literal> |
| 22 | 82 configuration parameter. |
| 83 <note> | |
| 84 If you were using the third-party mp4 module, be sure to disable it. | |
| 85 </note> | |
| 86 </para> | |
| 87 | |
| 88 <para> | |
| 89 A similar pseudo-streaming support for FLV files is provided by the module | |
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Added support for <link url="..."> which should eventually replace
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90 <link doc="ngx_http_flv_module.xml">ngx_http_flv_module</link>. |
| 22 | 91 </para> |
| 92 | |
| 93 </section> | |
| 94 | |
| 95 | |
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53
60796d056dde
Renamed section name "Usage example" to "Example Configuration"
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96 <section id="example" name="Example Configuration"> |
| 22 | 97 |
| 98 <para> | |
| 99 <example> | |
| 100 location /video/ { | |
| 101 mp4; | |
| 102 mp4_buffer_size 1m; | |
| 103 mp4_max_buffer_size 5m; | |
| 104 } | |
| 105 </example> | |
| 106 </para> | |
| 107 | |
| 108 </section> | |
| 109 | |
| 110 | |
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ae5aca1efe2c
Using new <module> and <section> format in ngx_http_mp4_module.xml.
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111 <section id="directives" name="Directives"> |
| 22 | 112 |
| 113 <directive name="mp4"> | |
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102
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The directive name is now automatically printed in <default> and <syntax>.
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114 <syntax/> |
| 22 | 115 <default/> |
| 116 <context>location</context> | |
| 117 | |
| 118 <para> | |
| 119 Turns on module processing in a surrounding location. | |
| 120 </para> | |
| 121 | |
| 122 </directive> | |
| 123 | |
| 124 | |
| 125 <directive name="mp4_buffer_size"> | |
| 271 | 126 <syntax><value>size</value></syntax> |
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The directive name is now automatically printed in <default> and <syntax>.
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127 <default>512K</default> |
| 22 | 128 <context>http</context> |
| 129 <context>server</context> | |
| 130 <context>location</context> | |
| 131 | |
| 132 <para> | |
| 133 Sets the initial size of a memory buffer used to process MP4 files. | |
| 134 </para> | |
| 135 | |
| 136 </directive> | |
| 137 | |
| 138 | |
| 139 <directive name="mp4_max_buffer_size"> | |
| 271 | 140 <syntax><value>size</value></syntax> |
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The directive name is now automatically printed in <default> and <syntax>.
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141 <default>10M</default> |
| 22 | 142 <context>http</context> |
| 143 <context>server</context> | |
| 144 <context>location</context> | |
| 145 | |
| 146 <para> | |
| 147 During metadata processing, a larger buffer may become necessary. | |
| 271 | 148 Its size cannot exceed the specified <value>size</value>, |
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Added support for <link url="..."> which should eventually replace
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149 or else nginx will return the server error |
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666e85596e3c
Added support for <link url="..."> which should eventually replace
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150 <http-status code="500" text="Internal Server Error"/>, |
| 22 | 151 and log the following: |
| 152 <example> | |
| 153 "/some/movie/file.mp4" mp4 moov atom is too large: | |
| 154 12583268, you may want to increase mp4_max_buffer_size | |
| 155 </example> | |
| 156 </para> | |
| 157 | |
| 158 </directive> | |
| 159 | |
| 160 </section> | |
| 161 | |
| 162 </module> |