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comparison xml/en/docs/http/ngx_http_mp4_module.xml @ 271:4c6d2c614d2c

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Cleaned up XML tag mess: - all of <parameter> and <code>, and some of <dirname>, <value>, and <command> were replaced by <literal>; - the rest of <dirname> were replaced by links; - <argument> were replaced by <value>; - <value> is now rendered in HTML in italic; - <literal> and <path> can now contain <value>. Cleaned up terminology mess: - directives take "parameters".
author Ruslan Ermilov <ru@nginx.com>
date Fri, 23 Dec 2011 17:29:59 +0000
parents 0188d11c77dd
children be54c443235a
comparison
equal deleted inserted replaced
270:945d7299c26c 271:4c6d2c614d2c
7 lang="en"> 7 lang="en">
8 8
9 <section id="summary"> 9 <section id="summary">
10 10
11 <para> 11 <para>
12 The module <code>ngx_http_mp4_module</code> provides pseudo-streaming 12 The module <literal>ngx_http_mp4_module</literal> provides pseudo-streaming
13 server-side support for H.264/AAC files typically having filename extensions 13 server-side support for H.264/AAC files typically having filename extensions
14 <path>.mp4</path>, <path>.m4v</path>, and <path>.m4a</path>. 14 <path>.mp4</path>, <path>.m4v</path>, and <path>.m4a</path>.
15 </para> 15 </para>
16 16
17 <para> 17 <para>
18 Pseudo-streaming works in alliance with conforming Flash players. 18 Pseudo-streaming works in alliance with conforming Flash players.
19 A player sends an HTTP request to the server with a start time 19 A player sends an HTTP request to the server with a start time
20 argument in the request URI’s query string (named simply 20 argument in the request URI’s query string (named simply
21 <parameter>start</parameter> 21 <literal>start</literal>
22 and specified in seconds), and the server responds with a stream 22 and specified in seconds), and the server responds with a stream
23 so that its start position corresponds to the requested time, 23 so that its start position corresponds to the requested time,
24 for example: 24 for example:
25 <example> 25 <example>
26 http://example.com/elephants_dream.mp4?start=238.88 26 http://example.com/elephants_dream.mp4?start=238.88
37 </para> 37 </para>
38 38
39 <para> 39 <para>
40 To start playback, a player first needs to read metadata. 40 To start playback, a player first needs to read metadata.
41 This is done by sending a special request with the 41 This is done by sending a special request with the
42 <parameter>start=0</parameter> 42 <literal>start=0</literal>
43 argument. Many encoding software will insert the metadata at 43 argument. Many encoding software will insert the metadata at
44 the end of the file. This is bad for pseudo-streaming: 44 the end of the file. This is bad for pseudo-streaming:
45 the metadata needs to be located at the beginning of the file, 45 the metadata needs to be located at the beginning of the file,
46 or else the entire file will have to be downloaded before it 46 or else the entire file will have to be downloaded before it
47 starts playing. If a file is well-formed (with metadata at the 47 starts playing. If a file is well-formed (with metadata at the
56 rather than having nginx do this on every such request. 56 rather than having nginx do this on every such request.
57 </para> 57 </para>
58 58
59 <para> 59 <para>
60 For a matching request with a non-zero 60 For a matching request with a non-zero
61 <parameter>start</parameter> 61 <literal>start</literal>
62 argument, nginx will read metadata from the file, prepare the 62 argument, nginx will read metadata from the file, prepare the
63 stream starting from the requested offset, and send it to a client. 63 stream starting from the requested offset, and send it to a client.
64 This has the same overhead as described above. 64 This has the same overhead as described above.
65 </para> 65 </para>
66 66
67 <para> 67 <para>
68 If a matching request does not include the 68 If a matching request does not include the
69 <parameter>start</parameter> 69 <literal>start</literal>
70 argument, there is no overhead, and the file is just sent as a static resource. 70 argument, there is no overhead, and the file is just sent as a static resource.
71 Some players also support byte-range requests, and thus do not require 71 Some players also support byte-range requests, and thus do not require
72 this module at all. 72 this module at all.
73 </para> 73 </para>
74 74
75 <para> 75 <para>
76 This module is not built by default, it should be enabled with the 76 This module is not built by default, it should be enabled with the
77 <code>--with-http_mp4_module</code> 77 <literal>--with-http_mp4_module</literal>
78 configuration parameter. 78 configuration parameter.
79 <note> 79 <note>
80 If you were using the third-party mp4 module, be sure to disable it. 80 If you were using the third-party mp4 module, be sure to disable it.
81 </note> 81 </note>
82 </para> 82 </para>
117 117
118 </directive> 118 </directive>
119 119
120 120
121 <directive name="mp4_buffer_size"> 121 <directive name="mp4_buffer_size">
122 <syntax><argument>size</argument></syntax> 122 <syntax><value>size</value></syntax>
123 <default>512K</default> 123 <default>512K</default>
124 <context>http</context> 124 <context>http</context>
125 <context>server</context> 125 <context>server</context>
126 <context>location</context> 126 <context>location</context>
127 127
131 131
132 </directive> 132 </directive>
133 133
134 134
135 <directive name="mp4_max_buffer_size"> 135 <directive name="mp4_max_buffer_size">
136 <syntax><argument>size</argument></syntax> 136 <syntax><value>size</value></syntax>
137 <default>10M</default> 137 <default>10M</default>
138 <context>http</context> 138 <context>http</context>
139 <context>server</context> 139 <context>server</context>
140 <context>location</context> 140 <context>location</context>
141 141
142 <para> 142 <para>
143 During metadata processing, a larger buffer may become necessary. 143 During metadata processing, a larger buffer may become necessary.
144 Its size cannot exceed the specified <argument>size</argument>, 144 Its size cannot exceed the specified <value>size</value>,
145 or else nginx will return the server error 145 or else nginx will return the server error
146 <http-status code="500" text="Internal Server Error"/>, 146 <http-status code="500" text="Internal Server Error"/>,
147 and log the following: 147 and log the following:
148 <example> 148 <example>
149 "/some/movie/file.mp4" mp4 moov atom is too large: 149 "/some/movie/file.mp4" mp4 moov atom is too large: