? adjusting loudness with ffmpeg

[hydra3333]

Looking for assistance with a windows .bat script to adjust loudness and convert to .mp2, via ffmpeg.

Can someone suggestion a simpler way to do it than below ?

So...

the outputs from these look interesting:

".\ffmpeg.exe" -y -vn -nostats -threads 8 -i ".\test.mpg" -af volumedetect -f null - > vol.max.txt 2>&1
".\ffmpeg.exe" -y -vn -nostats -threads 8 -i ".\test.mpg" -filter_complex ebur128 -f null - > vol.ebur128.txt 2>&1

If I can somehow in DOS extract the value from lines in those files into variables, eg

[Parsed_volumedetect_0 @ 049ae8a0] max_volume: -7.7 dB

in this case into VOLM=-7.7
and

I: -25.1 LUFS

in this case into VLUFS=-25.1
and then, in DOS, calculate

adjVOLM=min(abs(VOLI),16)
adjLUFS= min(abs(max(-23-VLUFS,0)),16)

Then I can choose which to use for ffmpeg volume adjustment
eg

ffmpeg  ...volume=volume=%myvariabe%dB:precision=float  ...

I'm not really sure whether to use the LUFS number or the max loudness number from "-af volumedetect". Which is "best" pragmatically ?

Anyway, here's the brute force way - looking forward to suggestions on a simpler way to do it.

@echo off
@setlocal ENABLEDELAYEDEXPANSION

@echo on
SET volFile=.\max.vol.vol.txt
".\ffmpeg.exe" -y -vn -nostats -threads 8 -i ".\test.mpg" -af volumedetect -f null - > %volFile% 2>&1
SET vbsf_vol=".\000-f1.vol.vbs"
REM @echo off
ECHO ' read vol from ffmpeg file and return the Maximum Volume value only > %vbsf_vol%
ECHO Const ForReading = 1 >> %vbsf_vol%
ECHO Dim objStdOut, objFSO , objFile, line, e, s, v, adj, er  >> %vbsf_vol%
ECHO 'Set objStdOut = WScript.StdOut  >> %vbsf_vol%
ECHO Set objFSO = CreateObject("Scripting.FileSystemObject") >> %vbsf_vol%
ECHO Set objFile = objFSO.OpenTextFile("!volFile!", ForReading) >> %vbsf_vol%
ECHO er = 1 >> %vbsf_vol%
ECHO v = 0 >> %vbsf_vol%
ECHO adj = 0 >> %vbsf_vol%
ECHO Do Until objFile.AtEndOfStream >> %vbsf_vol%
ECHO    line = lcase(objFile.ReadLine) >> %vbsf_vol%
ECHO    if instr(line,lcase("max_volume:")) > 0 then >> %vbsf_vol%
ECHO       s = instr(line,lcase("max_volume:")) + 11 >> %vbsf_vol%
ECHO       e = instr(line,lcase("dB")) - 1 >> %vbsf_vol%
ECHO       'WScript.StdOut.WriteLine "line=" ^& line >> %vbsf_vol%
ECHO       'WScript.StdOut.WriteLine s ^& " " ^& e  >> %vbsf_vol%
ECHO       if s^<=0 or e^<=0 then  >> %vbsf_vol%
ECHO          exit do >> %vbsf_vol%
ECHO       end if >> %vbsf_vol%
ECHO       v = trim(mid(line,s,e-s+1)) >> %vbsf_vol%
ECHO       'WScript.StdOut.WriteLine "string v=" ^& v >> %vbsf_vol%
ECHO       v = cdbl(v) >> %vbsf_vol%
ECHO       'WScript.StdOut.WriteLine "cdbl v=" ^& v >> %vbsf_vol%
ECHO       adj = min(abs(v),16) >> "%vbsf_vol%"
ECHO       adj = max(adj-1,0) >> "%vbsf_vol%"
ECHO       'WScript.StdOut.WriteLine "adj=" ^& adj >> %vbsf_vol%
ECHO       er = 0 >> %vbsf_vol%
ECHO       exit do >> %vbsf_vol%
ECHO    end if >> %vbsf_vol%
ECHO Loop >> %vbsf_vol%
ECHO WScript.StdOut.WriteLine adj >> %vbsf_vol%
ECHO objFile.Close >> %vbsf_vol%
ECHO set objFile = nothing >> %vbsf_vol%
ECHO set objFSO = nothing >> %vbsf_vol%
ECHO wscript.quit(er) ' 1=error. 0=ok >> %vbsf_vol%
ECHO function Max(a,b) >> %vbsf_vol%
ECHO     Max = a >> %vbsf_vol%
ECHO     If b ^> a then Max = b >> %vbsf_vol%
ECHO end function >> %vbsf_vol%
ECHO function Min(a,b) >> %vbsf_vol%
ECHO     Min = a >> %vbsf_vol%
ECHO     If b ^< a then Min = b >> %vbsf_vol%
ECHO end function  >> %vbsf_vol%
for /f "tokens=*" %%i in ('cscript //B //NOLOGO %vbsf_vol%') do set adjVOL=%%i
ECHO The value adjVOL=!adjVOL!

pause

@echo on
set ebur128File=max.vol.ebur128.txt
".\ffmpeg.exe" -y -vn -nostats -threads 8 -i ".\test.mpg" -filter_complex ebur128 -f null - > %ebur128File% 2>&1
SET vbsf_ebur128=".\000-f1.ebur128.vbs"
@echo off
ECHO ' read ebur128 from ffmpeg file and return the Integrated Loudness I value only > %vbsf_ebur128%
ECHO Const ForReading = 1 >> %vbsf_ebur128%
ECHO Dim objStdOut, objFSO , objFile, line, e, s, v, adj, er  >> %vbsf_ebur128%
ECHO 'Set objStdOut = WScript.StdOut  >> %vbsf_ebur128%
ECHO Set objFSO = CreateObject("Scripting.FileSystemObject") >> %vbsf_ebur128%
ECHO Set objFile = objFSO.OpenTextFile("!ebur128File!", ForReading) >> %vbsf_ebur128%
ECHO er = 1 >> %vbsf_ebur128%
ECHO v = 0 >> %vbsf_ebur128%
ECHO adj = 0 >> %vbsf_ebur128%
ECHO Do Until objFile.AtEndOfStream >> %vbsf_ebur128%
ECHO    line = lcase(objFile.ReadLine) >> %vbsf_ebur128%
ECHO    if instr(line,lcase("Integrated loudness:")) > 0 then >> %vbsf_ebur128%
ECHO       line = lcase(objFile.ReadLine) >> %vbsf_ebur128%
ECHO       s = instr(line,lcase("I:")) + 2 >> %vbsf_ebur128%
ECHO       e = instr(line,lcase("LUFS")) - 1 >> %vbsf_ebur128%
ECHO       'WScript.StdOut.WriteLine "line=" ^& line >> %vbsf_ebur128%
ECHO       'WScript.StdOut.WriteLine s ^& " " ^& e  >> %vbsf_ebur128%
ECHO       if s^<=0 or e^<=0 then  >> %vbsf_ebur128%
ECHO          exit do >> %vbsf_ebur128%
ECHO       end if >> %vbsf_ebur128%
ECHO       v = trim(mid(line,s,e-s+1)) >> %vbsf_ebur128%
ECHO       'WScript.StdOut.WriteLine "string v=" ^& v >> %vbsf_ebur128%
ECHO       v = cdbl(v) >> %vbsf_ebur128%
ECHO       'WScript.StdOut.WriteLine "cdbl v=" ^& v >> %vbsf_ebur128%
ECHO       v = -23 - v >> %vbsf_ebur128%
ECHO       'WScript.StdOut.WriteLine "-23-v v=" ^& v >> %vbsf_ebur128%
ECHO       adj = min(abs(max(v,0)),16) >> %vbsf_ebur128%
ECHO       'WScript.StdOut.WriteLine "adj=" ^& adj >> %vbsf_ebur128%
ECHO       er = 0 >> %vbsf_ebur128%
ECHO       exit do >> %vbsf_ebur128%
ECHO    end if >> %vbsf_ebur128%
ECHO Loop >> %vbsf_ebur128%
ECHO WScript.StdOut.WriteLine adj >> %vbsf_ebur128%
ECHO objFile.Close >> %vbsf_ebur128%
ECHO set objFile = nothing >> %vbsf_ebur128%
ECHO set objFSO = nothing >> %vbsf_ebur128%
ECHO wscript.quit(er) ' 1=error. 0=ok >> %vbsf_ebur128%
ECHO function Max(a,b) >> %vbsf_ebur128%
ECHO     Max = a >> %vbsf_ebur128%
ECHO     If b ^> a then Max = b >> %vbsf_ebur128%
ECHO end function >> %vbsf_ebur128%
ECHO function Min(a,b) >> %vbsf_ebur128%
ECHO     Min = a >> %vbsf_ebur128%
ECHO     If b ^< a then Min = b >> %vbsf_ebur128%
ECHO end function  >> %vbsf_ebur128%
for /f "tokens=*" %%i in ('cscript //B //NOLOGO %vbsf_ebur128%') do set adjLUFS=%%i
ECHO The value adjLUFS=!adjLUFS!

pause
exit

[tebasuna51]

Originally Posted by hydra3333

...
adjVOLM=min(abs(VOLI),16)
adjLUFS= min(abs(max(-23-VLUFS),0)),16)
...
I'm not really sure whether to use the LUFS number or the max loudness number from "-af volumedetect". Which is "best" pragmatically?

Reading:
http://www.ffmpeg.org/ffmpeg-filters.html#toc-volumedetect
http://www.ffmpeg.org/ffmpeg-filters.html#toc-ebur128
http://tech.ebu.ch/loudness

you can use:
adjVOL=min(adjVOLM,adjLUFS)
because you can never amplify more than adjVOLM without clip and more than adjLUFS to avoid high volume.