[Linphone-users] BUGS: H.264 stream probably invalid + crash

[Petr Macháček - 2N]

Hello Linphone developers,

I'm testing some piece of my software with Linphone. When I make a call from Linphone to my software, the video from Linphone has bad quality, it contains artifacts that are typical for H.264. Using WireShark, I saved the stream from Linphone to pcap format and extracted the H264 stream from that. I then analyzed this stream with the H.264 Stream Analysis program (https://sourceforge.net/projects/h264streamanalysis/).

This program shows that the H264 stream from Linphone is very strange. It contains several I-frames at the beginning followed by a long series of P-frames. Normally it is typical for I-frames to be many times larger than P-frames, but from Linphone both I-frames and P-frames are similarly large (~1kB).

 

I note that Linphone is the only software that my program has a problem with. I've tested it with a number of other devices (e.g. GrandStream GXV3275, various IP cameras...) and I haven't had a problem with H.264 video anywhere.

 

I am attaching a screenshot of the H.264 Stream Analysis program with the stream from the Linphone (linphone.png) and another screenshot with the stream from the IP camera where the stream is not corrupted (good_h264.png).

I am also sending a link to a zip file that contains both a pcap dump from Wireshark that contains the Linphone stream and the extracted h264 stream from Linphone:

 

https://drive.google.com/file/d/12Mw95AtQonDwy-6-cq0Q05HN4YwmxJR3/view?usp=sharing

 

Another problem a Linphone crash:

When I call from Linphone to GrandStream GXV3275, Linphone asks whether I want to turn on video. I click Confirm and the Linphone crashes.

 

Linphone: Desktop 4.3.0, Core 5.0.39.

OS: Windows 10 Pro (21H1, build 19043.1288)

PC: Notebook Dell Latitude 5491

 

Best regards

Petr Machacek

 

 

 

good_h264.png
Description: good_h264.png

linphone.png
Description: linphone.png