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Video+Audio out of sync in rtsp record-app (rtp-record) h.264+AAC audio

Hello,

There is a problem in my recorded MP4 files on the (rtp-record) app which I’ve created to only record the main stream of other apps.

Video+Audio is out of sync. I have tried to change rtp and stream-caster properties on the “streaming app” but that didn’t help.

On Wowza Streaming Engine 4.3.0 I think everything was okay. But on 4.4.1 the problem happens.

The only solution that worked for me was setting Audio to MP3 instead of AAC. But on smil I have to re-encode to AAC for ios devices.

Also when I manually record a rtmp (liverepeater) stream file the result is okay.

I used the default settings for the applications. I have tried both Main 4.1 & Baseline 4.1 h.264 profiles but it didn’t make a difference. Also, recording it as FLV didn’t solve the issue.

Recording the streams using “Record all incoming streams” on the “streaming app” works fine. But the problem in (rtp-record).

Also, I tried to re-stream a file using ffmpeg & libx264 Main 4.1 profile in order to re-generate the issue. But I think the result was fine.

I stream using vMix (FMLE 3.2 encoder) h.264 Main 4.1 2 seconds. 854x480 25fbps 500 kbps AAC 48000 112k.

The recorded files from ffmpeg using same settings there is no difference except maybe yuv420p from ffmpeg & yuv420p(tv) from FMLE.

There is no difference on Wowza Streaming Engine 4.3.1 recorded files & 4.4.1 except that the audio+video is not in sync on the later.

I have created 2 live applications 1 used for streaming & the 2nd records the rtsp stream (rtp-record) with save all incoming streams option turned on.

Regards,

Hi,

I’ can see changes have been made and they’re listed in the Wowza Streaming Engine 4.4.0 Release Notes.

Improved the live-record recording process to ensure that audio and video are in sync by trimming audio and video from the start of recordings if audio is delayed from video.

You may be able to resolve this by adding a buffer to the recording application to re-align the audio/video but this shouldn’t be required given the above changes.

Please test the application with the sort buffer enabled and if you’re still having this issue, open a ticket with our support team

When creating a ticket, Please provide a ZIP file containing a detailed description of the problem, a copy of the [Wowza-Install]/conf/ directory and latest log files for analysis.

Linking to this thread for reference will also be very useful.

Regards,

Jason

Hi,

From your conf/logs, it looks like you are pushing an RTMP stream to teststream application, and then connecting the output RTSP stream to the test-record application via MediaCaster. Do you only notice the audio/video sync issues in the recordings? The live stream playback has no audio/video sync issues?

Michelle

Hi,

Unfortunately, I have not been able to replicate the a/v sync issue using a similar setup (but without using VMix). When using FMLE or Wirecast directly (without using VMix), do you get the same issue?

Michelle

Hello,

I have tried adding a buffer but it didn’t help with AAC rtp-record sync issue.

I have uploaded a zip file with (config dir, stream files & access logs. there is nothing with value in error logs)

http://www.mediafire.com/download/m6wamw857w6tpt9/conf_4.4.1_AAC_rtp-record_problem.zip

Regards,

Hello,

Yes, streaming RTMP on “teststream” application then RTSP stream from this application is connected to “test-record” application as (rtp-record).

The live playback has no AV sync issue. Also the recorded files using “Record all incoming streams” on the original application “teststream” has no sync issue.

The recorded h.264+MP3 using (rtp-record) with “Record all incoming streams” turned on on second application “test-record” has no sync issue.

The problem happens when I stream AAC+h.264 and try to record it using (rtp-record) on the second application.

I have done another test today by streaming h.264 + MP3 which doesn’t have this issue. Then to record from “teststream_240p” that was transcoded to AAC. And I had same AAC+h.264 A/V out of sync in the recorded MP4 file. So I think that the problem lies on the recording side.

Regards,