[FFmpeg-user] FFPLAY plays some audio files at their native amplitude while others are playing 3dB down in amplitude

Rick Keniuk daddyo323 at gmail.com
Mon Mar 9 22:38:55 EET 2020

I have a sine wave audio test file generated with Matlab in FLAC and 
also WAV formats which load into several audio applications at full 
scale amplitude (16-bit sine wave peaks at +32767 and -32767).  The 
other applications play this file at maximum full scale amplitude yet 
FFPLAY plays the file at 3dB down from maximum amplitude.  Converting 
the file with FFMPEG to other formats results in an identical amplitude 
file which is full scale also. Other programs play this file at maximum 
amplitude but FFPLAY again is at -3dB from full scale.  Is there a 
command that I need to issue to FFPLAY to make it play at the native 

Here is my command:

C:\ffmpeg\bin\ffplay -volume 100 Sine_65s_997Hz at FS_44.1k_16b_int16.flac

The sine wave FLAC file is 1.7MB and I can provide that if that would be 

Odd thing here is that I have tried several song files, and even live 
audio streams in FFPLAY, and they play at the correct full scale amplitude.

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