[mythtv-users] Video too slow on some mpeg2's (actually layer 1 audio problem)

[Roger Heflin]

Ken Mandelberg wrote:
> I posted recently about a problem with using the internal player with 
> mpeg2's imported from an HD Tivo. They played properly with 
> mplayer/xine/vlc, but not the internal player. I described it as slow 
> video since the internal player was dropping frames and getting behind 
> the audio.
> 
> I thought the problem was the resolution which was a little different 
> than the HD streams captured directly on myth.
> 
> As it turns out, thats not it. It the audio. The Tivo mpeg2's have
> 
>    Audio : Mpeg 1 layer 1
>    free bitrate 44100 Hz
> 
> while the internally captured streams are
> 
>    Audio : Mpeg 1 layer 3
>    192 kbps  32000 Hz
> 
> I can get around the problem by transcoding which will convert it to 
> layer 3, but thats expensive and I would rather process the video as 
> little as possible.

If you just copy through the video it is not that bad
("-ovc copy" in mencoder).

Converting ac3 to mp3 takes me about 6-7 minutes of real time for a 60
minute show, so long as I only copy through the video as it, this
is with either a 3.2 Ghz P4, or a 2Ghz AMD CPU.

                             Roger