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I am using the concat demuxer to concat some wav files.
ffmpeg -safe 0 concat -i files.txt -c copy output.wav
files.txt stores files as:
file 'C:\Users\folderpath\input1.wav'
file 'C:\Users\folderpath\input2.wav'
etc
How can I add a -b into this command to set the bitrate? Right now without it, the files are being sped up--input files are 256kbps and output is 705kbps. I've tried several -b and -ab at different parts of the command, and cannot get this to work.
Ashley Guinan
Posted 2017-12-28T17:42:46.533
Reputation: 21
What are the properties of the two files?
ffprobe file. Bitrate for WAV files is a simple fixed function =bitdepth x sampling rate x no. of channels– Gyan – 2017-12-28T18:11:04.593The input properties are:
Metadata: encoder : Lavf57.73.100
Duration: 00:00:01.15, bitrate: 256 kb/s
Output properties are:
Metadata: encoder : Lavf58.2.103
Duration: 00:00:13.82, bitrate: 705 kb/s
Input properties are same for both files? – Gyan – 2017-12-28T18:27:18.813
No, that was the problem. Thank you!
I had some files that were 256k that were actual sound, and was trying to fill with empty sound using ffmpeg -y -f lavfi -i aevalsrc=0:duration=2 silence.wav
the aevalsrc defaults to 44100 Hz, I fixed it by adding a sample rate: ffmpeg -y -f lavfi -i aevalsrc=0:duration=2:sample_rate=16000 -acodec pcm_s16le silence.wav – Ashley Guinan – 2017-12-28T18:46:23.833