RTP reordering buffer

[fdurrey]

Hello everyone,
I looked over in the forums but could not find the answer to my question.
I am using VLC to send and receive video streams using RTP. I am using RTP because the network through which I am sending the packets tends to reorder the packets slighly.

The reordering is as such:
- Most packets arrive in the right order
- A few packets arrive with 1 packet delay
(ex: the receivers gets packets: 1,2,3,5,4,6,7,8,...)
- A very small number of packets arrive with about 20 packets of delay
(ex: the receiver gets packets: 1,2,3,5,6,...,22,23,4,25,16,27,...)

My problem is the following: the VLC client (which reveices the video and displays it) is capable of reordering the packets that arrive with 1 packet delay without any error on the video).
But packets which arrive with a longer delay (about 20 packets) are not reordered and that creates an error on the video.

I am sending MPEG1 video at roughly 166 packets/seconds so 20 packets is smaller than 150 ms and changing the --udp-caching value to several seconds does not make any change to the problem.

I must mention I am using VLC 0.8.5 (This was not working at all with 0.8.2).

Has anyone any idea on what the problem is? Is there a maximum size (maybe 16?) of the RTP buffer used to reorder the packets in VLC? Is there a way to change that (configuration or even change in the code) ? Where is it located in the code if I want to make a change?

Thanks for our support!

Best regards

Florent Durrey

[md]

You need to change the RTP reordering timeout (default is 100 msec).

Code: Select all

UDP/RTP input --udp-caching <integer> Caching value in ms --rtp-late <integer> RTP reordering timeout in ms

Preferences->Input/Codecs->Access modules->UDP/RTP (advanced options)