Hi all, newbie here - so please bear with me :-)
In short, I am trying to capture video from vhs, via a tv capture card. But
the A-V is out of sync - audio lags video. Actually, it becomes
progresssively worse as the recording goes on.
The details:
PC: dual Xeon 3Ghz (that's 4 CPUs), with 2G memory.
Fedora 11, with stock apps, codecs, etc (from repos - no rebuilds).
kernel 2.6.30-9-96
Pinnacle PCTV HD800i w/ Conexant cx23880 chipset.
driver loaded: cx8800
Sound Card: SB Live (EMU10K1) - driver snd_emu10k1
I have tried both ALSA and OSS. ALSA seems to work the best, but I keep
getting XRUNS.
Also, if I just capture raw audio/video, then I also get better sync (almost
perfect). But my i/o and disk drives can't seem to handle that much of a
stream before the video buffer fills up and audio frames start dropping.
Since I am using V4L2 to access the capture card, I am using this tv option
to mencoder:
-tv "input=1:alsa:adevice=hw.1,0:amode=1:immediatemode=0:mjpeg:decimation=1"
For OSS, I remove 'alsa', and change the adevice to '/dev/dsp1'.
The entire mencoder line (for raw dump) is:
mencoder -tv "{options above}" -oac copy -ovc copy -vf harddup -idx -noskip
-mc 0 -ni -o ofile.avi tv://
I have tried using mp3lame and lavc for audio encoders, and lavc for video,
but that just seems to make the de-syncing to happen faster.
Here is the output of mencoder when I run it:
[ken at Bugs root]$ mencoder -tv
"input=1:alsa:adevice=hw.1,0:amode=1:immediatemode=0:mjpeg:decimation=1"
-oac copy -ovc copy -vf harddup -noskip -idx -ni -mc 0 -o
/xfs/vhs-raw-test.avi tv://
MEncoder SVN-r29701-4.4.1 (C) 2000-2009 MPlayer Team
success: format: 9 data: 0x0 - 0x0
TV file format detected.
Selected driver: v4l2
name: Video 4 Linux 2 input
author: Martin Olschewski <olschewski at zpr.uni-koeln.de>
comment: first try, more to come ;-)
Selected device: Pinnacle PCTV HD 800i
Tuner cap:
Tuner rxs:
Capabilites: video capture VBI capture device tuner read/write
streaming
supported norms: 0 = NTSC-M; 1 = NTSC-M-JP; 2 = NTSC-443; 3 = PAL-BG; 4 =
PAL-I; 5 = PAL-DK; 6 = PAL-M; 7 = PAL-N; 8 = PAL-Nc; 9 = PAL-60; 10 =
SECAM-B; 11 = SECAM-G; 12 = SECAM-H; 13 = SECAM-DK; 14 = SECAM-L;
inputs: 0 = Television; 1 = Composite1; 2 = S-Video;
Current input: 1
Current format: BGR24
v4l2: current audio mode is : STEREO
v4l2: ioctl set format failed: Invalid argument
v4l2: ioctl set format failed: Invalid argument
tv.c: norm_from_string(pal): Bogus norm parameter, setting default.
MJP: width 704 height 576
[V] filefmt:9 fourcc:0x59565955 size:704x480 fps:29.970 ftime:=0.0334
videocodec: framecopy (704x480 24bpp fourcc=59565955)
audiocodec: framecopy (format=1 chans=2 rate=48000 bits=16 B/s=192000
sample-4)
Forcing audio preload to 0, max pts correction to 0.
Writing header...1f ( 0%) 0.00fps Trem: 0min 0mb A-V:0.000 [0:0]
ODML: Aspect information not (yet?) available or unspecified, not writing
vprp header.
Writing header...
ODML: Aspect information not (yet?) available or unspecified, not writing
vprp header.
Writing index... 46f ( 0%) 22.19fps Trem: 0min 0mb A-V:0.000
[162039:1536]
Writing header...
ODML: Aspect information not (yet?) available or unspecified, not writing
vprp header.
. . . . . . . . . . (snip out alot of the following repeated lines) . . . .
. .
video buffer full - dropping frame
too bad - dropping audio frame !
too bad - dropping audio frame !
too bad - dropping audio frame !
too bad - dropping audio frame !
Pos: 109.5s 3281f ( 0%) 23.37fps Trem: 0min 0mb A-V:0.000
[162039:1536]
too bad - dropping audio frame !
Writing index...3436f ( 0%) 23.83fps Trem: 0min 0mb A-V:0.000
[162039:1536]
Writing header...
ODML: Aspect information not (yet?) available or unspecified, not writing
vprp header.
Video stream: 162039.560 kbit/s (20254945 B/s) size: 2322186240 bytes
114.648 secs 3436 frames
Audio stream: 1536.000 kbit/s (192000 B/s) size: 22080000 bytes 115.000
secs
v4l2: 4295 frames successfully processed, 29 frames dropped.
I have tried many permutations of alsa vs oss, different output coders, etc.
But no luck.
I have been fighting with this for a long time. So any help/pointers will be
greatly appreciated.
TIA
ken
