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View Full Version : decode 5.1 audio with ffmpeg and pipe to neroaacenc ?


Selur
7th October 2008, 09:28
Is there a way to decode 5.1 audio with ffmpeg and pipe to neroaacenc such that the output will still be 5.1?
(aiming to use this on linux and windows systems)

for stereo the following works fine:
ffmpeg -i "path to audio input" -acodec pcm_s16le -ac 2 -ar 48000 -f wav - | neroAacEnc -if - -br 128000 -ignorelength -of "path to audio output"

But I somehow can't find a way to get this working if the source is 5.1. (small 5.1 sample http://www.selur.info/Test-AC3-5.1.zip)

Cu Selur

Kurtnoise
7th October 2008, 09:46
try this:

ffmpeg -i input.avi -vn -acodec pcm_s16le -ac 6 -f wav - | neroAacEnc -ignorelength -br 128000 -if - -of audio.m4a

buzzqw
7th October 2008, 10:01
ffmpeg -i audio.ac3 -acodec pcm_s32le -ac 6 -ar 48000 -f wav - | neroAacEnc -if - -br 128000 -ignorelength -of audio.mp4

the same for this
ffmpeg -i test-ac3-5.1.avi -vn -acodec pcm_s32le -ac 6 -ar 48000 -f wav - | neroAacEnc -if - -br 128000 -ignorelength -of audio2.mp4

is working with ffmpeg 14277 and neroaacenc 1.3.3.0

BHH

tebasuna51
7th October 2008, 16:21
...

is working with ffmpeg 14277 and neroaacenc 1.3.3.0


Is working?

With:
FFmpeg version Sherpya-r14277, Copyright (c) 2000-2008 Fabrice Bellard, et al.
libavutil version: 49.7.0
libavcodec version: 51.60.0
libavformat version: 52.17.0
libavdevice version: 52.0.0
built on Jul 18 2008 11:12:48, gcc: 4.2.4 [Sherpya]

Seems still have wrong channel mapping, DialNorm attenuation (here -4dB) and apply DRC.

buzzqw
7th October 2008, 16:38
... well ..is encoding
my setup is unable to detect wrong channel maps

BHH

Selur
7th October 2008, 18:28
Okay, found my problem: Installed PowerDVD some days ago and it didn't like the streams and I thought ffdshow was decoding the stream.
So general encoding works with ffmpeg and neroaacEnc
-> Now looking for a way to fix the channel mapping. :)