[mythtv-users] Transcoding to mp4 to reduce file size

Richard Freeman r-mythtv at thefreemanclan.net
Sun Nov 11 01:15:35 UTC 2007

Chris Isip wrote:
> I found a ffmpeg formula for transoding to ipod
> touch and it did just that.  The quality was acceptable for playback
> fullscreen on my TV as well , but mythtv will not play it ( I tried
> renaming the transcoded file to the original filename). 

I've found that mythtv is VERY picky regarding input audio/video format.
 For a long time I've been trying to transcode HD content down to SD
while preserving the AC3 soundtrack and I've never found a method that
works reliably.  For starters the seektable is designed around keyframes
being located at perfectly-spaced intervals.  It also doesn't help that
mencoder isn't good at syncing audio and video when using AC3 - probably
because it doesn't know how to adjust the AC3 if needed.  Getting video
to work in mplayer isn't hard at all - but myth is a lot pickier.
Sometimes I wonder if it wouldn't make sense just to rewrite the video
engine of myth to just use xine/mplayer/etc for actual playback, and
then keep the value-added stuff in myth proper (interface, commercial
skipping, OSD, etc.).  However, I'm not complaining as I realize that
this HAS to be a lot of effort!

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