WebRTC frozen frame when publishing in H264

[Hai_Pham]

I’ve setup Wowza 4.6.0 and use the latest WebRTC sample code to publish/play from the Chrome browser. I enable save incoming stream on Wowza, as well as transcoding to H264/AAC output.

When I use Chrome browser on laptop and publish to WebRTC, the publish stream works fine and I can playback the stream from another browser instance. The SDP and Wowza logs indicate that the codecs used are VPX(VP8) for Video and Opus for Audio. The log shows decode-video-start & decode-audio-start when publishing start.

However, when I use Chrome browser on my Android phone (Samsung Galaxy S7), the publish video stream freezes after a few seconds. When checking SDP and Wowza logs it look like H264 is picked up for Video instead of VPX (Audio is still Opus though). The log only shows decode-audio-start (no decode-video-start) when publishing start.

If I take out H264 support for WebRTC in Application.xml and only leave VP8 as the supported video codec, then my Android phone publishing works fine.

Is this a known issue? Can you reproduce this on your side? Thanks.

[Jason_Tuchler]

Hello,

I’m not seeing this issue with Android with Chrome version 54.0.2840.85. I would recommend going with this order in your webrtc Application.xml in this Property container:

webrtcPreferredCodecsVideo

vp8,h264

String

Please save and restart the application when making changes.

If that does not work, I would recommend opening a support case along with the below info.

[install-dir]/conf

[install-dir]/logs

[install-dir]/transcoder

[install-dir]/htdocs

Browser console log from Developer tools

If you are not sure how to get this information please see the following tutorial.

https://www.wowza.com/docs/how-to-create-a-compressed-zip-file-in-windows-os-x-and-linux

If files are too big for email transport, please send a link to the files.

Regards,

JasonT

[Benjamin_Le_Bozec]

Hi,

I’m having quite the same issue. When encoding using h264 (bitrate around 1500kbits/s), the playback starts to freeze after few seconds. When monitoring the stream in “incoming streams”, i see :

Bytes In: 61586824 @ 1.370 Mbits/s

Bytes Out: 94700 @ 159.590 Kbits/s

That confirms the freeze…

However, when using vp8 i don’t face any trouble.

Is that an issue ?

Regards,

Ben

[Jason_Tuchler]

Hello @Benjamin Le Bozec

I would recommend that you use the latest WebRTC HTML/JS files and try UDP vs TCP to see if you get different results. If you need a link to the files, please open a support ticket here.

Regards,

JasonT