Is frequency scanning working ?

[wvthoog]

Hi,

i'm using rx_fm and ffmpeg to scan and pipe nautical vhf transmissions to my server. But it seems it only locks to one frequency and does not initiatie a scan. Figured this out by using a second RTL-SDR and seeing several transmission pass by within the submitted range. Tried using multiple frequencies and passing a range.

So these are the commands i used.

Multiple frequencies:
rx_fm -f 156.200M -f 156.300M -f 156.423M -f 156.575M -f 156.650M -f 156.725M -f 156.975M -M fm -s 12k -g 50 -l 10 - | ffmpeg -f s16le -sample_rate 12k -i pipe:0 -acodec libmp3lame -b:a 64k -f rtp rtp://home.server:2121

Range:
rx_fm -f 156M:160M:25k -M fm -s 12k -g 50 -l 10 - | ffmpeg -f s16le -sample_rate 12k -i pipe:0 -acodec libmp3lame -b:a 64k -f rtp rtp://home.serverl:2121

Any help is highly appreciated