record issue sound very low

Donny Viszneki donny.viszneki at
Sun Dec 23 13:35:31 PST 2012

Contrast your two pipelines. What is different about them? Try to do
differential diagnostic between the two pipelines. This is a general
diagnostic technique. Try to test the difference between two scenarios
with as few differences as possible, so that you can isolate the
undesired behavior.

Differences in your pipelines that I notice:

Second pipeline encodes audio (ffenc_ac3,) whereas first pipeline does
not encode audio.

Your audio source (alsasrc) is using a different parameter:
 - pipeline 1: device="alsa_input.usb-Samson_Technologies_Samson_UB1-00-UB1.analog-stereo"
 - pipeline 2: device="alsa_input.usb-Samson_Technologies_Samson_UB1-00-UB1"

Another observation I would like to make is that I think ffenc_ac3
does not output mp3, though the fact that you can play your
"audio.mp3" file afterwards suggests to me that your player isn't
having a problem with this.

First thing I would look at is the alsasrc "device" parameter.

On Sun, Dec 23, 2012 at 11:55 AM, Claude Vittoria
<claude.vittoria at> wrote:
> Hi!
> I m discovering gstreamer to record audio and I got an issue. I m looking
> for an explication.
> I tried a test
> gst-launch -e pulsesrc
> device="alsa_input.usb-Samson_Technologies_Samson_UB1-00-UB1.analog-stereo"
> ! audioconvert ! audioresample ! pulsesink
> device="alsa_output.pci-0000_00_04.0.analog-stereo"
> and it works very well, good sound in the headphone
> but
> gst-launch -e alsasrc
> device="alsa_input.usb-Samson_Technologies_Samson_UB1-00-UB1" ! queue !
> audioconvert ! \
>   ffenc_ac3 ! filesink location=audio.mp3
> the mp3 is not audible, the sound comes from far far far distance as the mic
> was not amplified.
> I tried to modify the settings through the gnome sound applet, alsamixer,
> pavucontrol without result
> What I do not understand in the pipeline concept ?
> I work with a debian sid.
> $gst-launch --version
> gst-launch-0.10 version 0.10.36
> GStreamer 0.10.36
> Thanks and Merry Christmas
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