1255408 - h264 packetization-mode=0 not working

Status: NEW

(Core :: WebRTC: Networking, defect, P3)

Description

[andysem]

Attachment: party_3fd823fb-b382-c0d2-d0fd-9fb04d55ee4a@webrtc:test_conf_91f4.mkv

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:45.0) Gecko/20100101 Firefox/45.0
Build ID: 20160304114936

Steps to reproduce:

We're developing an MCU software that has support for WebRTC clients. We're having a problem with Firefox 45, when h264 codec is used for video and packetization-mode=0 (single NALU mode, https://tools.ietf.org/html/rfc6184#section-5.6) is negotiated.

The problem is two-fold. First, the video send by the browser looks heavily overcompressed (see the attached sample).

Second, and most importantly, the video that is sent by our software is not rendered by Firefox. Instead, the video window is black. I can verify that the packetization code in our software is correct because the very same code works when packetization-mode=1 is negotiated but video is packetized in single NALU mode on our end (which is allowed by the RFC) - the video is rendered in Firefox in this case. Note that in single NALU mode we send multiple packets per frame (i.e. a single frame can be encoded into multiple NALUs, each is sent in a separate RTP packet). All such packets have the same RTP timestamp.

As part of my experiments I also tried to negotiate packetization-mode=1 but send RTP payload that corresponds to packetization-mode=0 from our software. The result is as follows: Firefox sends RTP payload for packetization-mode=1, which is not overcompressed, but it doesn't render video from our software.

I also attached the SDPs. The SDP offer that was generated by the browser and set as the local description is attached as sdp_client.txt. The SDP answer that was generated by our software and set as the remote description is attached as sdp_server.txt. Note that the payload with packetization-mode=1 is removed from the answer.

I can see there was a similar bug #1050461 which is supposed to be fixed, but either the bug is not fixed or a different bug manifests itself similarly now. Hence the separate bug report.

I'm using Firefox 45 on Kubuntu 15.10 x86_64. I've also had the same problem with video not being rendered in Firefox 44.0.2, although I didn't check the video that was being sent by the browser.


Actual results:

1. The video sent by Firefox is overcompressed.
2. Firefox does not render the received video.


Expected results:

1. I would expect video quality to be comparable between packetization-mode=0 and packetization-mode=1.
2. The received video should be rendered. Both in case when packetization-mode=0 is negotiated as the preferred (or the only) mode and when packetization-mode=1 is preferred, but the payload for packetization-mode=0 is actually received.

Comment 1

[andysem]

Attachment: sdp_client.txt

Comment 2

[andysem]

Attachment: sdp_server.txt

Comment 3

[Randell Jesup [:jesup] (needinfo me)]

See also bug 1167544

Comment 4

[Bulk Bug Changes for mreavy's org]

Mass change P2->P3 to align with new Mozilla triage process.