[mythtv] [PATCH] Mac OS X audio patch
nigel at ind.tansu.com.au
Mon Aug 30 01:24:47 EDT 2004
> Just so Nigel doesn't have to do all the work on the OS X port, a
> patch is attached for Core Audio output under Mac OS X.
Jeremiah, thank you, thank you, thank you, thank you.
I was wondering how I was going to translate 48KHz little-
endian ints to 41KHz big-endian floats, and you have done
the hard work for me.
I still want to write a raw-device level driver so that
Darwin/X11 users can get sound, but this is great.
Don't suppose you know how to drive the HAL directly?
> It's been (lightly) tested under 10.3. Works pretty well in
> audio-only mode (my test Cube can't keep up on the video, with or
> without sound).
Playing back a clip is OK for about a second, but then it stutters.
This could be a CPU load thing (my box only just keeps up with the
or it could be some bug in the timing. NVP outputs:
Input #0, mpeg, from
Stream #0.0: Video: mpeg2video, 720x576, 25.00 fps
Stream #0.1: Audio: mp2, 48000 Hz, stereo, 256 kb/s
VideoOutputQuartz::Init(width=720, height=576, aspect=1.777778, winid=11
winx=0, winy=0, winw=1024, winh=768, WId
2004-08-30 15:07:24 Changing from None to WatchingPreRecorded
clipped negative delay: -267327512
clipped negative delay: -11288
clipped negative delay: -31852
clipped negative delay: -31871
before it starts stuttering, and then lots of similar lines:
clipped negative delay: -13534
clipped negative delay: -137755
clipped negative delay: -310
clipped negative delay: -125538
clipped negative delay: -127112
clipped negative delay: -56101
clipped negative delay: -206557
clipped negative delay: -81674
clipped negative delay: -126628
If I redirect this output to /dev/null, it doesn't stutter
and mostly keeps up. Sometimes the video is delayed, but it only
lasts about 0.5 seconds, and then audio is back in sync.
Give that a try!
Nigel Pearson, nigel at ind.tansu.com.au | "Peacemaking is our profession"
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