[mythtv] A/V Bug in CVS from 12:00am 3/27 to 12:00am 3/29

[Greg Grotsky]

I've been trying to narrow down the issue with audio jitter and
slow-mo video.  I've determined that it was broken in CVS sometime
between 3/27/2005 and 3/29/2005.  I checked out CVS MythTV from
3/27/2005 and it works for all channels, when I check it out from
3/29/2005 (because 3/28 backend segfaults when entering livetv) two
channels break.  The broken channels give me studdering audio (with
occasional pops and clicks) and the video is very slow.  When I tune
to a broken channel on the frontend I get lots of these:

2005-04-15 13:01:33.664 Audio buffer overflow, audio data lost!
2005-04-15 13:01:33.668 Audio buffer overflow, audio data lost!
2005-04-15 13:01:33.668 Audio buffer overflow, audio data lost!

And on the backend I get lots of these:

2005-04-15 13:01:35.624 DVB#0 WARNING - Uncorrectable error in packet, dropped.
2005-04-15 13:01:35.624 DVB#0 WARNING - Uncorrectable error in packet, dropped.
2005-04-15 13:01:35.624 DVB#0 WARNING - Uncorrectable error in packet, dropped.

Both channels work fine on CVS from 3/27 and earlier.  I looked
through the CVS commits from 3/27-3/29 and I'm not sure but these (2)
are the most relevant commits that I could find.

----------------------------------------------------------------------------
Changes committed by taylor on Sun Mar 27 18:18:56 2005

Modified Files:
   in mythtv/libs/libmythtv:
        dbcheck.cpp siparser.cpp siscan.cpp sitypes.cpp sitypes.h 
Log Message:
Addition of Torbjorn Jansson's EitFixUp4 code changes that were missed
in previous
DVB patch changes.  One more entry added to dtv_privatetypes so one more
schema rev.
----------------------------------------------------------------------------
----------------------------------------------------------------------------
Changes committed by cpinkham on Mon Mar 28 05:01:39 2005

Modified Files:
   in mythtv/libs/libmythtv:
        NuppelVideoPlayer.cpp NuppelVideoPlayer.h avformatdecoder.cpp 
        decoderbase.cpp decoderbase.h 
   in mythtv/programs/mythtranscode:
        transcode.cpp 
Log Message:

Fix transcoding bug related to AC3 passthrough.  Previously if you had AC3
passthrough turned on and tried to transcode an AC3 recording, the audio
would not be properly transcoded.  This fixes the audio when AC3 passthrough
is enabled.
----------------------------------------------------------------------------

I am using DVB with a pcHDTV HD-3000 card, on 32-bit Debian with a
2.6.12-rc1 kernel (with built-in DVB), I am also using /dev/dsp for
audio.  I used the same configure script with all versions of the CVS
code that I checked out, and I dropped my database to guarantee
identical settings.  Here is my output from configure that I am using:

$ ./configure  --disable-audio-arts --disable-audio-jack
--disable-firewire --disable-ivtv --enable-dvb
--dvb-path=/usr/src/linux/include --enable-xvmc --enable-opengl-vsync
Warning: DVB location points into kernel (ok if kernel >= 2.6.11)
# Basic Settings
Compile type     release
Compiler cache   no
DistCC           no
Install prefix   /usr/local
CPU              x86 (model name        : AMD Athlon(tm) 64 Processor 3200+)
Big Endian       no
MMX enabled      yes
Vector Builtins  no

# Input Support
Joystick menu    yes
lirc support     yes
ivtv support     no
FireWire support no
DVB support      yes [/usr/src/linux/include]

# Sound Output Support
OSS support      yes
ALSA support     yes
aRts support     no
JACK support     no

# Video Output Support
x11 support      yes
xrandr support   yes
xv support       yes
XvMC support     yes
XvMC VLD support no
OpenGL vsync     yes

Creating config.mak and config.h

P.S. I have XvMC enabled in configure but I don't have it enabled in
mythfrontend.

Thanks,
-Greg