I went through troubles to get work scrobbling for mp3 files synced from pc to my 3G iphone through the gtkpod. I finally found out that the tracks scrobbling works only with audio rate 22050. Scrobbling stops working when the song is sampled 44100 times per second.
Working code:
ffmpeg -i source_video.flv -ar 22050 -ab 128 -ss 00:00:01 -t 00:00:10 sound.mp3
No scrobbling:
ffmpeg -i source_video.flv -ar 44100 -ab 128 -ss 00:00:01 -t 00:00:10 sound.mp3
-ab 128k, not-ab 128. The-aboption takes a value in bits, not kilobits, so you're telling it to use 128 bits per second. Even better is to replace-abwith-aq, such as-aq 4(similar tolame -V). Better yet is to simply copy the audio if the flv already contains MP3 audio:ffmpeg -i input -acodec copy output.mp3. – LordNeckbeard Dec 12 '12 at 17:08