mp4 vod lip sync issue on iOS after 2 hours of playing.
I encounter an issue with Wowza when doing mp4 vod. I have a 4 hours mp4 movies, I put it on Wowza and play it with iPad(do vod), at the beginning, everything is ok, but 2 hours later, I encounter the lip sync issue on iPad, audio is lagged behand 2~3seconds, the longer it plays, the more serious the issue. Then I play the mp4 with VLC on Windows, everything is OK no matter how long it play. My Wowza is 4.1, can you pls help to address this?
Can you please provide more detail about the source:
What are the audio and video codecs?
What is the bitrate and profile?
Frames per second and GOP(keyframe frequency)?
For iOS it is recommended that you use a profile of baseline 3, or main at the highest, as well as AAC audio. H264 video is required.
Try different FPS and keyframe frequency settings. Key frame frequency should be a multiple of 10, the default for chunkDurationTarget, or a multiple of whatever you have set that to if you changed it.
This article describes the properties that you can use to control how the Cupertino (iOS device) segmenter segments an incoming stream:
Chunks must start on a key frame, so it's best to use a key frame interval that is factor of the cupertinoChunkDurationTarget setting. For example, if cupertinoChunkDurationTarget is set to 10 seconds then use a key frame interval of either 2, 2.5, 5, or 10 seconds.
By default, cupertinoChunkDurationTarget is set to 10 seconds.