Hi, You're right. The 3Mbps speed is as expected.
However, this still doesn't explain why my FFmpeg command requires 95% of my device's CPU to record raw audio audio, when the equivalent Arecord command takes 5% of my CPU. Again, here are my two commands: arecord -v -r48000 -c2 -fS32_LE --period-size=16384 --buffer-size=65536 -Dmic_sv -twav /dev/null ffmpeg -f alsa -acodec pcm_s32le -i mic_sv -c copy -f null - On Sat, Feb 18, 2017 at 12:38 PM, Moritz Barsnick <barsn...@gmx.net> wrote: > On Fri, Feb 17, 2017 at 20:56:25 -0800, christina zou wrote: > > 2. My ALSA bitrate is shown as 3072 kbps. This seems high - I only have a > > Pi Zero. Is this a value I can manually set? > > Why is that high and why should a Pi not be able to handle a standard > audio stream? 32 bits per sample, 48000 samples per second, two > channels, that makes exactly 3072000 bits per second. There's nothing > that can (or should) be done about that, that's how uncompressed audio > works. > > If you can get your ALSA device to output less bts per sample, or less > samples per second, you can reduce that rate, but I still don't > understand why. > > Moritz > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
