Latest snapshot of gqrx on Lubuntu 13.10

[pilleus pulcher]

Hi,

I installed the latest snapshot of gqrx on Lubuntu 13.10 and I'm able to listen FM radio with a Terratec Cinergy TStick RC (rev. 3) with E4000 Tuner. Thank you for your work!

One question: I can choose two FM modes (mono and stereo), but there is no difference to hear, I tested it with the built-in speakers of my notebook, with external speakers and headphones. The source is broadcasting in stereo. Is it an issue with my antenna?

Thank you for reading,

Thomas.

[Alexandru Csete]

Well, just because the station transmits in stereo, it doesn't mean
the contents are stereo. Do you hear it differently on another radio?
It could be an error in the demodulator but it is most certainly not
an issue with the antenna.

Alex

[pilleus pulcher]

Hello Alex,

thank you for the quick reply.

Using a radio I can hear stereo, e. g. Bayern 1 on FM at 95.0 MHz. All the FM radio stations I can hear in stereo with every radio.

If I use the Terratec Cinergy TStick RC I have an excellent output and I can see that more CPU time is used using FM stereo (compared to FM mono) - but no difference in listening.

Thomas.

[Alexandru Csete]

Ok thanks for the info, I filed a bug report about this.

Alex

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[pilleus pulcher]

Hi Alex,

I recorded two music pieces, the first in FM mono, the second in FM stereo (.wav).

Played with mplayer in a terminal both wav-files are listed with

...
Detected file format: WAV format (libavformat)
[wav @ 0xb6045440]max_analyze_duration reached
[lavf] stream 0: audio (pcm_s16le), -aid 0
Load subtitles in .
==========================================================================
Opening audio decoder: [pcm] Uncompressed PCM audio decoder
AUDIO: 48000 Hz, 2 ch, s16le, 1536.0 kbit/100.00% (ratio: 192000->192000)
Selected audio codec: [pcm] afm: pcm (Uncompressed PCM)
==========================================================================
AO: [pulse] 48000Hz 2ch s16le (2 bytes per sample)
...

I think, that the one recorded with FM mono should be listed with

...
AUDIO: 48000 Hz, 1 ch,
...

Am I wrong?

Thank you,

Thomas.

Am Montag, 9. Dezember 2013 10:32:18 UTC+1 schrieb pilleus pulcher:

[Alexandru Csete]

Gqrx always records 2 channel wave file. Obviously, it's not optimal
and waste of space but it would require significant amount of work to
change it to record different number of channels.

Alex

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[pilleus pulcher]

Ok, thank you for the information.

I played the stereo wav-file with mplayer in two ways to verify the problem with the stereo output.

There is no difference in listening between

...
mplayer xxx.wav
...

and

...
mplayer -af pan=1:1 -channels 1 xxx.wav
...

Thomas.

Am Montag, 9. Dezember 2013 10:32:18 UTC+1 schrieb pilleus pulcher: