[mythtv] [PATCH] Add streaming output to transcoder

Chris Petersen lists at forevermore.net
Fri Aug 15 10:35:43 EDT 2003


> A few random comments:
> 1) This patch differs from the previous prototype in that mythtrancsode
> will create/delete the fifos.  If they are already present, mythtranscode
> will fail.  This seems to ensure the initial sync happens correctly.

Does this mean that it wouldn't work (if you changed the code so it
wouldn't break if they're already present) if it tried to write an an
existing fifo?  I ask because svcd encoding is a two-stage process -
first video, then audio.  And I don't have enough RAM for mythtranscode
to hold onto a "raw" audio buffer while I encode video for an hour or
four.

Anyway, it would be really nice if mythtranscode could work with files
or fifos - ie. write to the file if nothing exists, or detect the fifo
and treat it like a fifo if one is already there (mplayer does this when
writing to yuv4mpeg format).  But if it doesn't work, maybe I can figure
something else out for svcd....

> 2) ffmpeg appears to also work for reading the raw streams (in case you
> don't have a CVS version of mencoder):
> ffmpeg -f u16le -ar 32000 -ac 2 -i <path>/audout -f rawvideo -s 640x480
> -r 29.97 -i <path>/vidout -vcodec mpeg4 -b 2000 -acodec mp3 -ab 128
> out.avi

awesome!  This means that I should be able to easily convert raw to yuv
for mpeg2enc!

-Chris



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