Random decoding starts without audio signal

[CRSourcing]

Hi Jon,

First I want to thank you for your work on this excellent decoder. I enjoy it a lot and it has been my "reference decoder" for SSTV experiments. I do however see frequent (mis) starts of the decoder, similar to what Antonino reported. It happens on average every 2 -5 minutes. The decoder seems to have a "preference" for the bw modes, but I have seen it with Robot36 as well. This happens with the audio input connected to a source, even if the source is muted, but also with the audio input grounded, so it doesn't seem to be caused by an input signal. Also, I tried changing the value in line 639, but it did not make any difference. Please let me know how I can help.

[dawsonjon]

@CRSourcing Thanks for your kind comments! I have been doing some development on the encoder branch including transmit and SD card decoding. In the latest code I am using a sync_counter value of 40. I'm not seeing too many false starts with this setting, and it still seems to be reasonably sensitive. If you don't have any success with this, I could try implementing something more sophisticated, perhaps using the magnitude or SNR to provide extra validation at the start of decoding.
Cheers
Jon

[CRSourcing]

Thank you, it's working better now, much less false starts, no longer an issue. Looking forward to your SD card implementation. I tried it with the ESP32 and there it depends much on the individual SD card.