Unable to capture audio from a tv tuner

[Charlie X. Liu]

What chipset on it (this particular capture card)? Sounds, its v4l2 driver
driving method is different from the common bttv & saa7134 drivers. 

 

From: gstreamer-devel-bounces+charlie=sensoray.com at lists.freedesktop.org
[mailto:gstreamer-devel-bounces+charlie=sensoray.com at lists.freedesktop.org]
On Behalf Of Edhoari Setiyoso
Sent: Saturday, March 02, 2013 2:45 PM
To: Discussion of the development of and with GStreamer
Subject: Re: Unable to capture audio from a tv tuner

 

I think I know why I cannot get audio at all from my capture card using
Gstreamer. The card audio input will be activated when I access the video
device. But gst-launch initialize the device with audio volume=0 aka mute.

I tested this behaviour using mplayer by varying the volume variable. The
effect is exactly the same as when I start mplayer with volume=0.

Unfortunately I cannot find any method to set the volume with gstreamer.

Is there anyone can give me a clue on how to set the volume with v4l2src?

Best Regards

 

On Sun, Mar 3, 2013 at 1:27 AM, Edhoari Setiyoso <edhoari.s at gmail.com>
wrote:

Hi Charlie,

I already confirmed that the audio device is that of tv tuner. The funny
thing is the audio device active only when I access the corresponding video
device. I can see from the audio mixer the audio level is moving. As soon as
I turn off the app accessing the video device, the audio level went down
completely.

 

Testing with mplayer showed that I must use "immediate=0" option, otherwise
I only get video. From the manual it says "A value of 0 means capture and
buffer audio and video together".

Could you give me a hint on this?

Regards

 

On Sat, Mar 2, 2013 at 2:40 AM, Charlie X. Liu <charlie at sensoray.com> wrote:

You need to use "arecord -l" to find out and confirm that the "hw:2,0" is
your "Avermedia Volar Go M"
(http://www.avermedia.com/avertv/Product/ProductDetail.aspx?Id=529
<http://www.avermedia.com/avertv/Product/ProductDetail.aspx?Id=529&tab=APDri
> &tab=APDri
ver) audio device link.

Then, simply use "arecord -D hw:2,0 | aplay" or "gst-launch-0.10 alsasrc
device=hw:1,0 ! audio/x-raw-int,rate=\
32000,channels=2,depth=16 ! audioconvert ! autoaudiosink" to confirm that
you can pre-listening from your device and the hardware works.

Next, apply your application ...

Good luck and BR,

Charlie X. Liu @ Sensoray Company Inc. (http://www.sensoray.com/)



-----Original Message-----
From: gstreamer-devel-bounces+charlie=sensoray.com at lists.freedesktop.org
[mailto:gstreamer-devel-bounces+charlie
<mailto:gstreamer-devel-bounces%2Bcharlie>
=sensoray.com at lists.freedesktop.org]
On Behalf Of edhoari
Sent: Friday, March 01, 2013 9:43 AM
To: gstreamer-devel at lists.freedesktop.org
Subject: Unable to capture audio from a tv tuner

Hi all,

I'm fairly new with Gstreamer and trying to build a application to digitize
analog video. I'm using Avermedia Volar Go M as capture device for composite
input.

My problem is that I cannot get any audio from it. I can capture video
without problem with the following command

gst-launch-0.10 v4l2src device=/dev/video1 !
'video/x-raw-yuv,width=640,height=480' ! ffmpegcolorspace ! xvimagesink

And here is the command to capture audio

gst-launch -e alsasrc device=hw:2,0 ! audioconvert ! lamemp3enc target=1
bitrate=128 cbr=true ! filesink location=audio.mp3

But I get nothing from audio input. I can confirm that the card is working
just fine because the following command can capture video and audio without
problem.

mplayer -tv
driver=v4l2:input=1:device=/dev/video1:alsa=1:adevice=hw.1:immediatemode=0
tv:// -ao sdl

This is audio capture card list in my system:

**** List of CAPTURE Hardware Devices **** card 0: Intel [HDA Intel], device
0: ALC883 Analog [ALC883 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: ALC883 Digital [ALC883 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 2: ALC883 Analog [ALC883 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: Cx231xxAudio [Cx231xx Audio], device 0: Cx231xx Audio [Conexant
cx231xx Capture]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Any help would be appreciated.

Regards



--
View this message in context:
http://gstreamer-devel.966125.n4.nabble.com/Unable-to-capture-audio-from-a-t
<http://gstreamer-devel.966125.n4.nabble.com/Unable-to-capture-audio-from-a-
t%0Av-tuner-tp4658837.html> 
v-tuner-tp4658837.html
Sent from the GStreamer-devel mailing list archive at Nabble.com.
_______________________________________________
gstreamer-devel mailing list
gstreamer-devel at lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

_______________________________________________
gstreamer-devel mailing list
gstreamer-devel at lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel





-- 

Edhoari Setiyoso




-- 

Edhoari Setiyoso

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/gstreamer-devel/attachments/20130304/3b02ed1e/attachment.html>