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miegl / PiFmAdv

Advanced Raspberry Pi FM transmitter with RDS encoding
GNU General Public License v3.0
484 stars 82 forks source link

Station dies after about an hour #84

Open cjuniorfox opened 3 years ago

cjuniorfox commented 3 years ago

I'm piping from arecord using snd_aloop device. The oscillation just dies after about one hour or two. The pi_fm_adv does not report any issue. The process keeps running like there's nothing wrong happened.

May be related with #40 but I really don't know.

I'm running raspibian jessy on Raspberry Pi 3B

Command follows

arecord -fS16_LE -r 44100 -Dplughw:0,0 -c 2 - --quiet | pi_fm_adv --wait 0 --freq 91.5 --audio - --ctl /tmp/rds_ctl --mpx 40 --preemph us

rashrf commented 3 years ago

Hi,

I can't quite believe that I am about to offer the same explanation (and solution) I offered to someone else on Github today, for a completely different project which also uses arecord. :-D

The problem is almost certainly arecord rolling the output every 2GB - a 32-bit limitation. I ran into a similar problem about eight years ago when using arecord to open an ALSA input device and pipe to another tool.

The workaround I found was to use ecasound to open the ALSA device instead and the problem went away.

Hope this works for you.

R

cjuniorfox commented 3 years ago

Thank you for your response. I installed ecasound and I successfully able to capture my alsa device to one wav file, but how do I write ecasound to stdout to pipe pi_fm_adv just like I do with arecord?

cjuniorfox commented 3 years ago

I believe the problem does not rely on aplay's buffer I tested several ways to feed the pifmadv. I tried pipping ffmpeg to stdin, with wav files, using named fifos. All with no success.

Additionaly, I tested the fm_transmitter (mono, 22050hz) with no problems at all. Unfortunely, with PiFmAdv, the oscillation is hardly sustained for more than some couple hours.