recording sound from pcm along with tv by mencoder

ted_chou12 · 09-08-2013, 08:36 AM

Hi, I found that this code records the signal of tv tuner:

Code:

#!/bin/bash
sox -t alsa hw:1,1 -t alsa hw:0,0 &

if [ $# -ne 3 ]
then
        echo "Usage: $0 channel seconds filename"
        exit
fi

WIDTH=640
HEIGHT=480
MENCODER=/usr/bin/mencoder
AUDIO="-oac pcm:file=/home/ted/file.wav -lameopts cbr:br=128:mode=3"
VIDEO="-ovc lavc -lavcopts vcodec=mpeg4:vbitrate=6400"
DSP="alsa:adevice=hw.0:forceaudio:amode=2:audiorate=44100:forceaudio:immediatemode=0"
TV=" -tv driver=v4l2:width=$WIDTH:height=$HEIGHT:outfmt=yuy2:input=0:device=/dev/video0:norm=NTSC:chanlist=us-cable:channel=$1:$DSP"
$MENCODER tv:// $TV $VIDEO $AUDIO -endpos $2 -ffourcc divx -o  "$3.avi"

pid=$(ps aux | pgrep "^sox")
kill $pid & exit

but the sound isnt recorded correctly. The tv tuner card comes out thru this binding:

Code:

sox -t alsa hw:1,1 -t alsa hw:0,0

The above line allows the sound of sound card to comeout from the speaker
So I thought it has to do with line-in, http://inspirated.com/2007/04/05/als...e-with-mplayer.
But I followed everything on the blog but nothing worked. I must have done something incorrectly.
Thanks,
Ted

teckk · 09-12-2013, 10:35 AM

Quote:

TV=" -tv driver=v4l2:width=$WIDTH:height=$HEIGHT

utfmt=yuy2:input=0:device=/dev/video0:norm=NTSC:chanlist=us-cable:channel=$1:$DSP"

Lets start with some info.
Are you trying to record an analog NTSC TV broadcast, or a digital broadcast?
Do you want to capture the audio that is coming through your sound card, or the audio portion of the TV broadcast?
Can you play the TV broadcast with mplayer? If so post your command line.

ted_chou12 · 09-13-2013, 05:45 AM

Thanks for your reply! I am trying to record NTSC TV broadcast with TV tuner card, and the sound input is thru the TV sound card. Although I am not very sure with the exact procedure, but I believe sox -t alsa hw:1,1 -t alsa hw:0,0this binds the TV card to the pcm input of the sound card to play the sound, the sound changes as I switch between channels. Since the sound could be played, I believe its technicallly possible to record the sound input, but not sure about whether I could get the sound in the same avi file (best if it could) or a separate sound file (if there is no better choice).
So far there is no problem playing TV bc with mplayer and the picture sound both show up fine. I could now record picture with mencoder but not with the sound.

Code:

WIDTH=640
HEIGHT=480
MPLAYER=/usr/bin/mplayer
AUDIO="-oac pcm:file=/home/ted/file.wav -lameopts cbr:br=128:mode=3"
VIDEO="-ovc lavc -lavcopts vcodec=mpeg4:vbitrate=6400"
DSP="alsa:adevice=hw.0:forceaudio:amode=2:audiorate=44100:forceaudio:immediatemode=0"
TV=" -tv driver=v4l2:width=$WIDTH:height=$HEIGHT:outfmt=yuy2:input=0:device=/dev/video0:norm=NTSC:chanlist=us-cable:channel=$1:$DSP"
$MPLAYER tv:// $TV $VIDEO $AUDIO -endpos $2 -ffourcc divx -o  "$3.avi"

Thanks,Ted

teckk · 09-13-2013, 08:30 AM

Quote:

So far there is no problem playing TV bc with mplayer and the picture sound both show up fine

How about

Code:

$MPLAYER tv:// .....-dumpstream -dumpfile output.avi

If mplayer can play it, you can dump it's output to file.

The audio from the tv card goes in to the sound card... You could make a loopback device and capture what is coming through line in, or what's coming out of the speakers.

A couple of threads.
http://www.alsa-project.org/main/ind...x:Module-aloop
https://bbs.archlinux.org/viewtopic.php?pid=1308977
https://bbs.archlinux.org/viewtopic.php?id=147852

EDIT: Upon closer reading,
These don't go together

Code:

-oac pcm:file=/home/ted/file.wav -lameopts cbr:br=128

That would need to need to be

Code:

-oac mp3lame -lameopts cbr:br=128