我正在尝试从 mp4 文件创建自适应流。我在做流媒体方面有相当多的经验，并且已经通过 Silverlight 成功地实现了流畅的流媒体。我们想要一个适用于 HTML5 的所有东西的解决方案。我正在追求 DASH。所以这是我采取的步骤......
- 使用 ffmpeg 将 mp4 重新采样为不同的大小。
- 使用 Bento4s mp4Fragment 实用程序确保文件正确分段。
- 使用 Bento4s mp4dash 实用程序创建 DASH mpd 文件和相关段。
我做了很多工作来学习这些实用程序中的每一个，并创建一个可以输出我认为可行的流程。创建可靠的 DASH 工件。但似乎我做错了什么。以下是我运行的命令行示例。
对于第一步，我创建了三个不同的文件......用于三种不同的速率和大小......（这些可能不是确切的命令行，它们来自旧笔记......但参数值是我确定使用的值)
ffmpeg -y -i C:\_SIMULATED_SHARE_C\ff\big_buck_bunny.mp4 -c:v libx264 -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 1500k -maxrate 1500k -bufsize 1000k -vf "scale=-1:720" C:\_SIMULATED_SHARE_C\ff\output\outputfile720.mp4
ffmpeg -y -i C:\_SIMULATED_SHARE_C\ff\big_buck_bunny.mp4 -c:v libx264 -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 800k -maxrate 800k -bufsize 500k -vf "scale=-1:540" C:\_SIMULATED_SHARE_C\ff\output\outputfile540.mp4
ffmpeg -y -i C:\_SIMULATED_SHARE_C\ff\big_buck_bunny.mp4 -c:v libx264 -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 400k -maxrate 400k -bufsize 400k -vf "scale=-1:360" C:\_SIMULATED_SHARE_C\ff\output\outputfile360.mp4
这样就为您提供了需要分段的三个文件。所以我使用 Bento4 的 mp4fragment 实用程序对它们进行分段。该命令行很简单，因此我不会提供示例。
我使用 Bento4s mp4dash 创建破折号。像这样的东西...
"E:\\_INSTALL\\Bento4\\Bento4-SDK-1-4-3-607.x86-microsoft-win32-vs2010\\Bento4-SDK-1-4-3-607.x86-microsoft-win32-vs2010\\bin\\mp4dash.exe --mpd-name=\"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\dash\\something.mpd\" -f -o \"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\dash\" \"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\bunny360f.mp4\" \"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\bunny540f.mp4\" \"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\bunny720f.mp4\" "
这运行正常。并创建 mpd 文件，一个带有片段文件的音频文件夹，一个带有 3 个文件夹的视频文件夹，每个文件夹带有片段文件。
我能够配置 IIS 来播放 mpd ok。以及分段文件。视频播放正常……然后就停止了。它会冻结 50 到 60 秒。就在它冻结之前，我可以确认 HTML5 视频标签的 onratechange 事件已引发。这是随着播放速率的变化而引发的事件。我没有做任何改变它只是发生。
有问题的实际视频长约 1 小时。我也使用 dash.js 库作为播放器。
如果您能确定我应该更改的任何组件或细节，请告诉我！
2016 年 3 月 7 日更新
这里要求的是 MPD 内容...
<?xml version="1.0" ?>
<MPD mediaPresentationDuration="PT51M51.909S" minBufferTime="PT0.80S" profiles="urn:mpeg:dash:profile:isoff-live:2011" type="static" xmlns="urn:mpeg:dash:schema:mpd:2011">
<!-- Created with Bento4 mp4-dash.py, VERSION=1.6.0-607 -->
<Period>
<!-- Audio -->
<AdaptationSet lang="en" mimeType="audio/mp4" segmentAlignment="true" startWithSAP="1">
<SegmentTemplate duration="801" initialization="$RepresentationID$/init.mp4" media="$RepresentationID$/seg-$Number$.m4f" startNumber="1" timescale="1000"/>
<Representation audioSamplingRate="48000" bandwidth="132491" codecs="mp4a.40.2" id="audio/en">
<AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"/>
</Representation>
</AdaptationSet>
<!-- Video -->
<AdaptationSet maxHeight="720" maxWidth="1280" mimeType="video/mp4" minHeight="540" minWidth="640" segmentAlignment="true" startWithSAP="1">
<SegmentTemplate duration="801" initialization="$RepresentationID$/init.mp4" media="$RepresentationID$/seg-$Number$.m4f" startNumber="1" timescale="1000"/>
<Representation bandwidth="785536" codecs="avc1.64001F" frameRate="30000/1001" height="540" id="video/1" scanType="progressive" width="960"/>
<Representation bandwidth="403537" codecs="avc1.64001E" frameRate="30000/1001" height="360" id="video/2" scanType="progressive" width="640"/>
<Representation bandwidth="1496514" codecs="avc1.64001F" frameRate="30000/1001" height="720" id="video/3" scanType="progressive" width="1280"/>
</AdaptationSet>
</Period>
</MPD>
2016 年 3 月 7 日更新
这是两个不同视频的控制台输出，它们在 50 到 60 秒之间因未知原因停止
///ABS VIDEO
58393][rulesController] [RULES]: playbackTimeRule [Fragment:download,82,MediaSegment,0video] Default
dash.all.js:11 [58395][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,82,MediaSegment,0,video] Default
dash.all.js:11 [58401][indexHandler][audio] Getting the request for time: 82.082
dash.all.js:11 [58403][indexHandler][audio] Index for time 82.082 is 81
dash.all.js:11 [58405][indexHandler][audio] SegmentTemplate: 81.08099999999999 / 1361.235
dash.all.js:11 [58406][indexHandler][audio] SegmentTemplate: 82.082 / 1361.235
dash.all.js:11 [58407][rulesController] [RULES]: playbackTimeRule [Fragment:download,82,MediaSegment,0audio] Default
dash.all.js:11 [58417][fragmentLoader] loaded video:MediaSegment:82.082 (200, 18ms, 2ms)
dash.all.js:11 [58419][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,82,MediaSegment,0,audio] Default
dash.all.js:11 [58435][fragmentLoader] loaded audio:MediaSegment:82.082 (200, 14ms, 0ms)
dash.all.js:11 [59390][indexHandler][video] Getting the request for time: 83.083
dash.all.js:11 [59392][indexHandler][video] Index for time 83.083 is 82
dash.all.js:11 [59393][indexHandler][video] SegmentTemplate: 82.082 / 1361.235
dash.all.js:11 [59394][indexHandler][video] SegmentTemplate: 83.08299999999998 / 1361.235
dash.all.js:11 [59395][rulesController] [RULES]: playbackTimeRule [Fragment:download,83,MediaSegment,0video] Default
dash.all.js:11 [59396][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,83,MediaSegment,0,video] Default
dash.all.js:11 [59401][indexHandler][audio] Getting the request for time: 83.083
dash.all.js:11 [59403][indexHandler][audio] Index for time 83.083 is 82
dash.all.js:11 [59404][indexHandler][audio] SegmentTemplate: 82.082 / 1361.235
dash.all.js:11 [59406][indexHandler][audio] SegmentTemplate: 83.08299999999998 / 1361.235
dash.all.js:11 [59408][rulesController] [RULES]: playbackTimeRule [Fragment:download,83,MediaSegment,0audio] Default
dash.all.js:11 [59416][fragmentLoader] loaded video:MediaSegment:83.08299999999998 (200, 17ms, 1ms)
dash.all.js:11 [59418][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,83,MediaSegment,0,audio] Default
dash.all.js:11 [59437][fragmentLoader] loaded audio:MediaSegment:83.08299999999998 (200, 14ms, 1ms)
dash.all.js:11 [59902][scheduleController][video] Stalling Buffer
dash.all.js:11 [59903][bufferController][video] Waiting for more buffer before starting playback.
dash.all.js:11 [59906][scheduleController][audio] Stalling Buffer
dash.all.js:11 [59907][bufferController][audio] Waiting for more buffer before starting playback.
dash.all.js:11 [63684][playbackController] <video> ratechange: 0
///HOG VIDEO
[58250][rulesController] [RULES]: playbackTimeRule [Fragment:download,105,MediaSegment,0audio] Default
dash.all.js:11 [58266][fragmentLoader] loaded video:MediaSegment:84.105 (200, 28ms, 1ms)
dash.all.js:11 [58269][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,105,MediaSegment,0,audio] Default
dash.all.js:11 [58287][fragmentLoader] loaded audio:MediaSegment:84.105 (200, 14ms, 1ms)
dash.all.js:11 [58982][indexHandler][video] Getting the request for time: 84.906
dash.all.js:11 [58983][indexHandler][video] Index for time 84.906 is 105
dash.all.js:11 [58984][indexHandler][video] SegmentTemplate: 84.105 / 3111.909
dash.all.js:11 [58984][indexHandler][video] SegmentTemplate: 84.906 / 3111.909
dash.all.js:11 [58985][rulesController] [RULES]: playbackTimeRule [Fragment:download,106,MediaSegment,0video] Default
dash.all.js:11 [58986][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,106,MediaSegment,0,video] Default
dash.all.js:11 [58989][indexHandler][audio] Getting the request for time: 84.906
dash.all.js:11 [58990][indexHandler][audio] Index for time 84.906 is 105
dash.all.js:11 [58991][indexHandler][audio] SegmentTemplate: 84.105 / 3111.909
dash.all.js:11 [58992][indexHandler][audio] SegmentTemplate: 84.906 / 3111.909
dash.all.js:11 [58993][rulesController] [RULES]: playbackTimeRule [Fragment:download,106,MediaSegment,0audio] Default
dash.all.js:11 [59002][fragmentLoader] loaded video:MediaSegment:84.906 (200, 14ms, 1ms)
dash.all.js:11 [59003][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,106,MediaSegment,0,audio] Default
dash.all.js:11 [59014][fragmentLoader] loaded audio:MediaSegment:84.906 (200, 8ms, 1ms)
dash.all.js:11 [59735][scheduleController][video] Stalling Buffer
dash.all.js:11 [59736][bufferController][video] Waiting for more buffer before starting playback.
dash.all.js:11 [59738][scheduleController][audio] Stalling Buffer
dash.all.js:11 [59739][bufferController][audio] Waiting for more buffer before starting playback.
dash.all.js:11 [61695][playbackController] <video> ratechange: 0