Bitrate Ignored for mpv2 codec

In version 2.0.3, the bitrate (vb=) parameter for sout using vcodec=mp2v is effective, from version 2.0.5 to 2.1.0, it seems to be ignored.

I tested this on an Ubuntu 12.04 64 bit system. The problem surfaced recently when I did an apt-get update and vlc updated from 2.0.3 to 2.0.5

I'm running a stream with the following sout string:

sout='#transcode{vcodec=mp2v,vb=1900,vt=100000,acodec=mpga,ab=128}:std{access=udp{ttl=1},mux=ts,dst=229.20.30.1:2300}'

After the update to 2.0.5, my network utilisation moved up to 4-6 mbps, rather than keeping to 2 mpbs, like it had been.

To check if the problem had been fixed I updated to a nightly build 2.1.0 (git20130225+r2486). The problem persisted. I then re-compiled 2.0.3 from source. The problem went away. Just to check, I re-compiled 2.0.5, the problem came back. One last switch back again to 2.0.3 and the problem went away.

I also tested on an Ubuntu 12.10 32 bit system with the same issue.

The VLC transcode plugin is strictly identical in all VLC versions from 2.0.0 through to 2.0.5. This is probably a change in the avcodec encoder. When building from source, it would be a good idea to run git-bisect (commit 88fe9f443f75fee558bd0a9c501985e4afd8bd08 seems like a potential suspect.)

assigned to @ileoo

added Component::Stream output: Encoders + 1 deleted label

491520518e91b2b8334f8d1fa586bc0c41db2168 is the suspect, you could try to set vcodec=avcodec{rc-buffer-size=1000000} instead of that vt-value (vt-setting is avcodec-setting too, and doesn't do anything in that transcode set).

Commit 0d7b2bd8 should fix this (2.2 nightlies builds if you want to test)

added Status::fixed label

changed milestone to %2.2.x maintenance branch

closed