Question

Here is our procedure:

We create live MP4 videos using ffmpeg (H264/AAC), both as API and as command line tool.*
qt-faststart is used to move the metadata to the beginning of the file to enable fast playback in our Flash client.
Video is renamed to *.m4v.
User uses our Flash client to download the video and starts playing immediatly due to the metadata being at the beginning.

Edit: *First, a MPG video is created with the ffmpeg API, this is then copied together with an intro and an outro video (you can simply chain MPG videos). The resulting MPG is then converted to MP4 using the following command:

ffmpeg -i inputvideo.mpg -sameq -b 3000000 -vcodec libx264 -acodec libvo_aacenc -ac 2 -g 60 -y outputvideo.mp4

基本上,这确实是行之有效的。

问题:

我们注意到,在最初的游击中(用户已经点击了任何东西,录像仍然下载或没有改变),录音是按时间顺序进行的,如果你看得见的话,就值得注意。

But as soon as you click around in the video (one time is enough, no matter where you click), the audio becomes more synchronous (still not perfect!) for the rest of the video.

这种行为也是一样的,无论你通过我们的闪电器或视窗媒体运动员来看待这种行为。难道我们能够从我们一方(从头开始或开始)做些什么来使它变得nch笑吗?

Answer 1

Ha!

Turns out the problem was in the audio not being the same length as the video. As soon as that got fixed, everything was synchronous again. Should have checked that one first... So, not really a coding bug or problem, more the fault of our content department. ;)

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