Ac3 with ffmpeg

[DVB-Freak]

Hello,

From 6 Monowavs I want to create a Ac3(5.1)-file with ffmpeg.
I use the following command:

c:\ffmpeg.exe -i d:\audio\test.L.wav -i d:\audio\test.R.wav -i d:\audio\test.C.wav -i d:\audio\test.LFE.wav -i d:\audio\test.SL.wav -i d:\audio\test.SR.wav -acodec ac3 -ab 448k -ac 6 d:\audio\test.ac3

Ffmpeg take only the 1st input, so the ac3 isn't correct.
Can someone explain, where is the mistake?

Thanks

[tebasuna51]

ffmpeg only accept one input file.

You can use Aften:
Aften -b 448 -ch_fl L.wav -ch_fr R.wav -ch_fc C.wav -ch_lfe LFE.wav -ch_sl SL.wav -ch_sr SR.wav test.ac3

[Kurtnoise]

you have to use avfilter (http://ffmpeg.org/libavfilter.html) (amix option)...

[spawnbsd]

Ffmpeg take only the 1st input, so the ac3 isn't correct.
Can someone explain, where is the mistake?

Try using SoX to combine them (see below), and then feed into ffmpeg/libav. I wouldn't recommend using Aften, the code isn't maintained, it lacks channel coupling and libav/ffmpeg's AC3 encoder has long surpassed it in quality.


%soxbin% -M audio_temp.L.wav audio_temp.R.wav audio_temp.C.wav audio_temp.LFE.wav audio_temp.SL.wav audio_temp.SR.wav audio_6-channel_TMP.w64

%libavbin% -i audio_6-channel_TMP.w64 -y -acodec ac3 -ab 640k -channel_coupling 1 audio.ac3

[ramicio]

%soxbin% -M audio_temp.L.wav audio_temp.R.wav audio_temp.C.wav audio_temp.LFE.wav audio_temp.SL.wav audio_temp.SR.wav audio_6-channel_TMP.w64

%libavbin% -i audio_6-channel_TMP.w64 -y -acodec ac3 -ab 640k -channel_coupling 1 audio.ac3


Why not just try to pipe it instead of taking up all that time and space?

sox -M L.wav R.wav C.wav LFE.wav SL.wav SR.wav -t w64 - | ffmpeg -i - -y -codec ac3 -ab 640k -channel_coupling 1 output.ac3

[spawnbsd]

Why not just try to pipe it instead of taking up all that time and space?

sox -M L.wav R.wav C.wav LFE.wav SL.wav SR.wav -t w64 - | ffmpeg -i - -y -codec ac3 -ab 640k -channel_coupling 1 output.ac3

Oh definitely, I just cut that out of a larger script of mine, where piping wasn't possible (its a larger script for 7.1 -> 5.1 w/ EX processing).

[ramicio]

I see.

[DVB-Freak]

@spanwnbsd
@ramicio

Thanks for your reply. I have the following commandline:
c:\sox\sox.exe -M d:\audio\test.L.wav d:\audio\test.R.wav d:\audio\test.C.wav d:\audio\test.LFE.wav d:\audio\test.SL.wav d:\audio\test.SR.wav -t test.w64 -
But there comes only an error:
c:\sox\sox.exe FAIL formats: no handler for given file type `test.w64'
Can you help me?

[DVB-Freak]

Hello,

Thanks all for the help. I have found a way to feed ffmpeg,
but you pointed me to the solution.

[ramicio]

The -t switch is to specify a file type, like for when you use pipe, because pipe isn't a file or filename, and gives sox no clue as to what format you want.

[Reino]

From 6 Monowavs I want to create a Ac3(5.1)-file with ffmpeg.ffmpeg -i fl.wav -i fr.wav -i fc.wav -i lfe.wav -i bl.wav -i br.wav ^
-filter_complex "[0:a][1:a][2:a][3:a][4:a][5:a]amerge=inputs=6" -c:a ac3 merge.ac3

[raffriff42]

ffmpeg.exe -i fl.wav -i fr.wav -i fc.wav -i lfe.wav -i bl.wav -i br.wav ^
-filter_complex "join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-LFE|4.0-BL|5.0-BR" ^
-ac 6 -channel_layout 5.1 -acodec ac3 -ab 448k merged.ac3

[tebasuna51]

raffriff42 was deleted the previous post like "redundant", but I think, if work, is good to know alternative syntax to solve the problem.

ffmpeg have many options unknow for many users (like me).

Maybe is a good idea open a post like "ffmpeg audio mannagement" to explain alternatives to common audio tasks than be solved with eac3to, sox or BeHappy/AviSynth.

There are a volunteer than know ffmpeg to do the job?

[Selur]

I agree, the whole ffmpeg audio filter stuff is relatively new and there aren't many usable examples (I'm aware off).