VAAPI AV1 does not send video track to WHIP output

[Bleuzen]

Operating System Info

Other

Other OS

Debian 13

OBS Studio Version

Other

OBS Studio Version (Other)

32.0.4

OBS Studio Log URL

https://pastebin.com/raw/Z6FWRSka

OBS Studio Crash Log URL

No response

Expected Behavior

OBS should upload an audio and video track

Current Behavior

OBS only uploads the audio track, video track is never sent to the streaming server

Steps to Reproduce

1. Set video encoder to VAAPI AV1
2. Stream using WHIP

Anything else we should know?

The streaming server logs show that it only receives the opus audio track but no video track.
I confirmed the video track is missing by looking at the network statistic of my system, it only shows a low upload rate, so the video is not sent.

It works when using H264 or HEVC. Only AV1 does not send the video track to the WHIP output.

Using AV1 CPU encoders also works, it is only broken with the VAAPI encoded AV1.

The VAAPI AV1 encoding itself works, I see the encoder usage going up when starting a stream and recording with it outputs a playable video file.

Streaming to a RTMPS output using VAAPI AV1 works.

The problem only occurs when streaming the VAAPI AV1 encoded video to a WHIP output.
Maybe the video track is not correctly packaged for WHIP?

[ghadi-rahme]

I can confirm that I have been experiencing the same issue for a while now.

I can reproduce the issue by using broadcast-box as a streaming server and OBS (obs-studio 32.0.2-2.1) running on CachyOS.

I have also noticed by looking at the wireshark data that packets are a very small when using VAAPI AV1 compared to SVT-AV1 and debugging with delve on broadcast-box also confirmed that only the audio is being received.

When debugging OBS, it seems like the video data is being sent as this code path is running and triggering breakpoints in GDB:

plugins/obs-webrtc/whip-output.cpp:

void WHIPOutput::Data(struct encoder_packet *packet)
{
...
...
	} else if (video_track && packet->type == OBS_ENCODER_VIDEO) {
		int64_t duration = packet->dts_usec - last_video_timestamp;
		Send(packet->data, packet->size, duration, video_track, video_sr_reporter);
		last_video_timestamp = packet->dts_usec;
	}
}

packet->size also seems to be fine and comparable to what I get when using SVT-AV1.

[ghadi-rahme]

Seems that it will be fixed in paullouisageneau/libdatachannel#1495

[Sean-Der]

PR against obs-deps fixes this obsproject/obs-deps#305