[MPlayer-dev-eng] video pipes
comiotto at rcfmedia.ch
Tue Mar 23 00:03:42 CET 2004
I'm trying to put together a small video broadcasting solution with mplayer as
playlist-based player and pdp as realtime video mixing component. Therefore I
need a way to pipe a/v from mplayer to pd. I am well aware that currently
there's no standardized solution to this problem (except of the
vloopback-hack or buying one capture card per channel and routing a/v via
hardware ports - unfortunately I can't afford that) but nevertheless I need
to come up with a solution. Before I start hacking on an output filter that
fits my needs I wanted to ask you to run your checks on what I possibly would
come up with - maybe there's a solution that I didn't think about yet or what
I plan to do is just plain bullshit, you never know...
Disclaimer: I am _very_ new to video programming, but basically have rather
decent programming skills.
PDP can read raw video data from a FIFO pipe. Currently the supported formats
V12 yuv data : [type bitmap/yv12/320x240]
rgb data : [type bitmap/rgb/320x240]
I ran a quick test with mplayer's -vo yuv4mpeg filter and the named pipe
approach sort of works, but besides a jittering audio channel because of
having mplayer waiting for pdp to pull the last frame of the stack before
pushing the next one to the stack I loose mplayer's seeking/transport
functionality when using this -vo filter. Of course we still want to be able
to do basic transport functions in the player. Is there a way of using
multiple output filters simultanously, feeding a pipe in the background while
still displaying an x-window and do seeking and the like?
What alternatives to the named pipe approach or possibly streaming locally via
udp/rtp (too expensive) do I have? Does anyone of you have some deeper
insights in what the status of exchanging video data between *nix apps is at
There seems to be no jack output module for mplayer available. Is anyone
working on that or would this also have to be done for piping the audio data
I hope someone can give me some hints on solving this one...
More information about the MPlayer-dev-eng