[Libav-user] need advice on new player
deron at pagestream.org
Sun Feb 19 04:38:59 CET 2012
I've been using a decklink driver for mplayer to output video to the
Blackmagic Decklink card but I've run into several problems which just
don't seem to have an easy fix. In talking with the original developer
of the decklink driver for mplayer, he agreed that the only reasonable
recourse was to write a customer player based on libav directly.
I've gone over his roughed out decklink player, I've looked at ffplay.c,
and the tutorial at http://dranger.com/ffmpeg/ and I have a decent idea
on what needs to be done on the decklink side but some items that
mplayer took care of I am still unsure off.
We are trying to work with all kinds of odd ball videos, and I have to
accommodate either odd ball audio streams like != 48kHz, or two audio
streams with mono samples instead of a single stereo stream, wrong
sample size, or something that is too loud. Something like "-af
resample=48000:0:2,channels=2,volume=-12,format=s16le" in mplayer would
be used. What I'm not finding in ffplay is how to implement something
The other minor case is when dealing with SD or 1080i video that needs
to be scaled and/or clipped. It appears that ffplay includes video
filters support. Correct? Am I just missing the support for the audio
At this point I am comfortable with implementing the decklink output
using either ffplay or dranger's source, but I'm not comfortable with
changes needs on the libav interface end of things to support the audio
filtering. I am sure I can just modify the buffered audio stream myself
to implement the functionality I need, but if optimized functioning code
I suppose the real question is, and no one but myself might be able to
answer it but here goes, what would be the best place to base this on?
It seems that modifying ffplay would be best?
Just looking for some inspiration, thanks!
More information about the Libav-user