I am using FFmpeg version 3.2.2 and LAME 3.99.5 on macOS Sierra (10.12.2) and I have this command that pipes FFmpeg output (from a FLAC file) to LAME for encoding into an MP3:
ffmpeg -y -v quiet -nostdin -i test.flac -b:a 320k -ac 2 -ar 44100 -f s16le -acodec pcm_s16le - | \ lame --quiet -r -m s --lowpass 19.7 -V 3 --vbr-new -q 0 -b 96 --scale 0.99 --athaa-sensitivity 1 - test.mp3;
It works fine and I am happy with the results, but when I remove the
-v quiet setting from the FFmpeg part of the pipe—so I can actually see what’s happening—I notice the following in the output:
Stream mapping: Stream #0:0 -> #0:0 (flac (native) -> pcm_s16le (native)) size= 81858kB time=00:07:55.18 bitrate=1411.2kbits/s speed=41.2x
Note the bitrate is being shown as
1411.2kbits during the conversion process and not the set bitrate of 320k from the
-b:a 320k option being set.
Is this expected behavior? Is that whole chunk of audio parameters (
-b:a 320k -ac 2 -ar 44100) superfluous when piping output via RAW output using
-f s16le -acodec pcm_s16le since that bitrate setting is being ignored?