[mythtv-users] Help with mythtranscode?

[Devin Mullins]

Hi all! Sorry to bug, but I'm having a heck of a time getting exporting
to work, and I'm not exactly an expert in the field, so I sort of
fumbling around in the dark.

So, the problem is, while audio encodes fine, and creates a nice 60MB
file for a 1/2 hour show (using nuvexport's default DVD settings), video
encodes three frames (1 I, 1 P, 1 B) and then just sits there, waiting,
until mythtranscode segfaults. The resulting mpeg that nuvexport
multiplexes together sends mplayer into a fritz.

Basically, all I've done to debug it so far is hand-run and decompose
the pipe chains that nuvexport runs (those being the mythtranscode
producer process, and the audio and video consumer processes) to see
where the point of failure is. I cut off the video pipechain (i.e. all
that's left running is ffmpeg), and nothing changed, so the problem's
either in mythtranscode, the whole fifo thing, or ffmpeg.

If anybody could help me get this up and running, I'd be quite grateful.
My myth partition is full, and my /var partition is filling up with
myth's complaints about that fact. :P Details follow my sig.

Thanks,
Devin
---
Pertinent info:
I'm using mythtv-0.13, as fetched by gentoo's emerge. USE="+alsa -lcd
-lirc +nvidia", though I doubt the nvidia XvMC thing's getting used.
CHOST="i686-pc-linux-gnu". CFLAGS="-O3 -march=athlon-xp -funroll-loops
-fomit-frame-pointer -pipe".

The show is stored in the .nuv as an MPEG-4 (software encoder), on
whatever the typical settings are.

Output of mythtranscode:
bash-2.05b# nice -n19 mythtranscode -p autodetect -c 1016 -s
2004-02-29-18-30-00 -f fifo --fifosync --honorcutlist
2004-03-20 16:56:17 Transcoding from
/home/mythtv//1016_20040229183000_20040229190000.nuv to
/home/mythtv//1016_20040229183000_20040229190000.nuv.tmp
2004-03-20 16:56:17 Enforcing sync on fifos
2004-03-20 16:56:17 Created video fifo: fifo/vidout
2004-03-20 16:56:17 Created audio fifo: fifo/audout
2004-03-20 16:56:17 Video 640x480 at 29.97fps Audio rate: 44100
2004-03-20 16:56:17 Created fifos. Waiting for connection.
2004-03-20 16:56:17 Audio is 64ms ahead of video at # 1
2004-03-20 16:56:22 Audio is 37ms ahead of video at # 4
2004-03-20 16:56:41 Audio is 36ms behind video at # 2242
2004-03-20 16:57:15 Audio is 48ms behind video at # 6319
2004-03-20 16:57:15 Audio is 35ms behind video at # 6320
2004-03-20 16:58:02 Fast-Forwarding from 12048 to 14595
2004-03-20 16:58:02 Audio is 43ms ahead of video at # 12047
2004-03-20 16:59:32 Fast-Forwarding from 25413 to 32011
2004-03-20 16:59:32 Audio is 56ms ahead of video at # 22865
2004-03-20 17:00:42 Fast-Forwarding from 40181 to 47683
2004-03-20 17:01:33 Fast-Forwarding from 53805 to 53850
Segmentation fault


Output of audio pipechain:
bash-2.05b# nice -n19 sox -t raw -r 44100 -s -w -c 2 fifo/audout -t raw
-r 48000 -s -w -c 2 - | nice -n19 toolame -s 48.0 -m j -b 384 - myaudio
--------------------------------------------
Input File : 'stdin'   48.0 kHz
Output File: 'myaudio'
384 kbps MPEG-1 Layer II j-stereo Psy model 1
[De-emph:Off    Copyright:No    Original:No     CRC:Off]
[Padding:Normal Byte-swap:Off   Chanswap:Off    DAB:Off]
ATH adjustment 0.000000
--------------------------------------------
encode_init: using tablenum 0 with sblimit 27
Hit end of audio data
Avg slots/frame = 1152.000; b/smp = 8.00; bitrate = 384.000 kbps

Done


Output of (abridged) video pipechain:
bash-2.05b# nice -n19 ffmpeg -f rawvideo -s 640x480 -r 29.97 -i
fifo/vidout -f yuv4mpegpipe - > mytestvid
Input #0, rawvideo, from 'fifo/vidout':
   Duration: N/A, bitrate: N/A
   Stream #0.0: Video: rawvideo, yuv420p, 640x480, 29.97 fps
Output #0, yuv4mpegpipe, to 'pipe:':
   Stream #0.0: Video: rawvideo, yuv420p, 640x480, 29.97 fps, q=2-31,
200 kb/s
Stream mapping:
   Stream #0.0 -> #0.0
Press [q] to stop encoding
frame=    3 q=0.0 size=    1350kB time=0.1 bitrate=110486.2kbits/s


Directory listing:
bash-2.05b# ls -l
total 59497
drwxr-xr-x    2 root     root           96 Mar 20 16:56 fifo
-rw-r--r--    1 root     root     59520384 Mar 20 17:01 myaudio
-rw-r--r--    1 root     root      1382459 Mar 20 16:56 mytestvid
-rw-r--r--    1 root     root          614 Mar 20 17:21 out.audio
-rw-r--r--    1 root     root          488 Mar 20 17:21 out.ls
-rw-r--r--    1 root     root         1179 Mar 20 17:20 out.mythtrans
-rw-r--r--    1 root     root          487 Mar 20 17:21 out.video