Need an mplayer/mencoder guru: capturing ALSA and BTTV

[adsmith]

Here's the setup:

The BTTV tuner card has
Audio -> external loopback wire -> on-board audio Line-IN
Video -> /dev/video0 is just fine (no onboard MPEG2 compression).

Here are the symptoms:

1) tvtime sees and hears just fine. No problems.
2) The "Capture" audio device in ALSA always hears the tv. That is, "arecord file.out" fills file.out with the audio stream of the last-tuned tv station.
3) mplayer and mencoder can see but NOT hear.


I have tried the following sorts of things, all with no resulting audio:

• mplayer tv://17 -tv driver=v4l2:device=/dev/video0:norm=NTSC:chanlist=us-bcast
  
• (similarly) mencoder tv://17 -tv driver=v4l2:device=/dev/video0:norm=NTSC:chanlist=us-bcast
  

and every combination of the "alsa" "forceaudio" and "immediatemode" setting for -tv.

Can anyone experienced with mplayer/mencoder please tell me how to get it to combine the obvious audio and video streams?

[Matteo Azzali]

try mplayer using device=/dev/video0:alsa:amode=1 ,if not working try to change to amode=0,
once you're sure mplayer works, you can start tweaking mencoder.
(ah, check with alsamixer that line is capturing source, capture settings shows up pressing F4 , and that
control line (output) is unmuted and has some volume, tvtime is the only app unmuting line control)
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[tuam]

[adsmith]

Matteo Azzali
Thanks for the suggestions, but they still result in no sound.

tuam

kernel is vanilla 2.6.15.1. All of the alsa and v4l modules are built from within this kernel (not from CVS or portage)

mplayer is media-video/mplayer-1.0_pre7-r1 -3dfx +3dnow +3dnowext +X +aac +aalib +alsa (-altivec) -arts -bidi -bindist -bl +cdparanoia -cpudetection -custom-cflags -debug -dga -directfb -doc -dts -dv -dvb +dvd +dvdread -edl +encode -esd -fbcon -ggi +gif +gtk -i8x0 -ipv6 -jack -joystick +jpeg -libcaca -lirc -live -livecd -lzo +mad -matroska -matrox +mmx +mmxext -mythtv -nas +nls +nvidia +opengl +oss +png +real -rtc -samba +sdl +sse -sse2 -svga -tga +theora +truetype +v4l +v4l2 +vorbis +win32codecs -xanim -xinerama -xmms +xv +xvid +xvmc

I'll emerge transcode and give that a try.

All of the appropriate alsa devices are unmuted and set to Capture. This is confirmed by arecord grabbing the Tuner's output.



I've also tried the patch for the snd_bt87x module mentioned in a nearby thread, and it produced /dev/[a]dsp1 for the tuner card, but I still can't get any input from those devices. So, I'm back to focusing on the sound card line-in, which I *know* is properly capturing audio, even if mplayer doesn't know about it.

[adsmith]

Confirmed: transcode (and nuppelvideo, for what it's worth) but can grab audio appropriately.

So, either there's a problem with mplayer seeing /dev/dsp at all, or I simply don't understand how to use it (more likely)
And yes, I have included adevice=/dev/dsp in the tv options...

[Matteo Azzali]

Can I give another senseless hint? try to filter out most of the use flags from mplayer, emerge just with
the strict-necessary flags, and try. I had big issues in the past with xvmc theora doc cpudetection and some other flags,
mplayer is working fine here only without these (also, is libtheora needed for mplayer to work with theora?
ebuild is lacking dependancy).

Actually on my system these flags are safe:

[tuam]

[Matteo Azzali]

[adsmith]

well, I have a work-around solution for myself.

I wrote a script which records in nuvrec (nuppelvideo package), then transcodes it to mpeg4. This works just fine for my freevo recordserver, so I'm happy enough for now...