Recording a rotating video stream

mediasoup libraries
1

Hello!

Trying to record video that comes from an iPad. It works, but when i am rotating iPad along the horizontal axis, video rotates in the recording while it fixes itself in the received stream. So basically if i put iPad upside down, my face will be upright on the stream my viewers receive real time over webrtc, but upside down in the recording.

Is there a way to fix this?

I am using RtpStreamer to record, and ffmpeg with a simplistic SDP to receive

v=0
o=- 0 0 IN IP4 127.0.0.1
c=IN IP4 127.0.0.1
t=0 0
a=tool:libavformat 56.15.102
m=audio ${Recorder.rtpPort(producer.kind,rtpIndex)} RTP/AVP 100
a=rtpmap:100 OPUS/48000/2
m=video ${Recorder.rtpPort(producer.kind,rtpIndex)} RTP/AVP 101
a=rtpmap:101 VP8/90000`;

, as you see no tricks (probably i need some SDP trick to support rotation, that’s what my guess is).

Thanks!

Alexander

PS: Weirdly enough, it works on Android tablet just fine. Problem is only on iPad. And iPhone too.

2

Could you try removing the below header extension from the video producer on the client/server side:

urn:3gpp:video-orientation
3

you mean remove it by hacking SDP on a client which sends the video? what will be the expected result of it?

4

It helped. Thanks! I wonder why?

5

It seems to be an iOS only problem.
When viewing/recording an iOS stream if both endpoints don’t support the video-orientation extension, the orientation of the iOS stream is not shown correctly. :thinking:

Removing the video-orientation header solves the problem, however the video may freeze if the device is rotated 270 degrees…