audio video out of sync in mp4 files only on chrome

[Peeyush Tuli]

Hi,

I manage a website where mp4 videos are streamed using wowza server /cloudfront for browsers and mobile devices. For chrome specifically we use cloudfront and pseudo-streaming as we are trying to move away from flash. We are facing a weird issue with some of our videos going out of sync w.r.t audio when played in chrome either as a local file or a url. We have a commercial jw player license but we have also used the cloudfront url directly in the browser with the same results. Due to the proprietary nature of the videos i cant share them on a public forum for review but if someone can has any pointers, it would be really helpful. Here are my observations regarding the same -

1) After analysis of all the videos, the common problem seems be that while those were recorded there wasn't any audio for the first few seconds. So if the video is played in any other browser ( E.g. html5 in firefox / hls in safari/ flash in ie) the audio is not there for those few seconds and then when it is audible its in sync with the video. But when the same video is played on chrome either through the direct cloudfront url or jwplayer it seems chrome ignores the no audio time and simply starts playing the audio from 0:00 along with the video leading to sync issues. The same thing happens when i download the video and play it as a local file.

2) Once the played video crosses the point from where the audio should ideally starts, then seeking back some seconds fixes the sync issue midway. Eg. if the audio starts at 0:05 and you seek to 0:06 after the video has played till 0:10 , the sync issue is fixed. But if you seek at 0:04 the issue still persists.

3) The same video played in firefox latest version works properly.

4) The video is encoded h.264 and the audio files are AAC.

I read few links which mentioned the issue could be there due to moov atom at the end of the file in videos generated by wowza but i did use a program to shift the moov atom at the beginning. Still the behaviour is same in Chrome.

Is there a specific difference between the mechanism of playing mp4 files between chrome and firefox which is the root cause?

[MSI Team]

Do you use any extensions? Which version of Chrome are you using?

[kulwinder rehal]

Hi Peeyush

Did you manage to resolve this problem?

I am facing the same issue with playing mp4 (H.264, AAC) files on chrome (and firefox) where there is some audio missing in the beginning. Mine is usually 4 seconds of delay in audio. 

I am finding a solution to either play them in sync in jplayer (which is not happening on chrome) or resolve the issue of audio delay in the beginning with Wowza.

Unfortunately I have neither found a solution from for audio delay in recording and audio/video sync in jplyaer with chrome.

How did you happen to solve it with either wowza or chrome?

Thanks in Advanve...