eac3to - audio conversion tool

[mastrandrea]

Is there a way to convert 6 mono wavs into 5.1 ac3?
Thanks in advance

[LigH]

Yes. Even if (probably?) not with eac3to.

BeSweet supports it via a *.mux file (you can use BeLight as GUI to create that and feed it into BeSweet). Unfortunately, the quality of the AC3Enc plugin is quite bad, and many versions have been bugged regarding a too low volume.

Also, Aften supports reading from six mono channel WAVs. WAV to AC3 Encoder is a useful GUI here. The Aften AC3 encoder is not yet close to commercial encoders, but still possibly the best current freeware AC3 encoder. WAV2AC3 uses Aften as stand-alone encoder; eac3to uses Aften as a library.

[the_weirdo]

Or this way:
http://forum.doom9.org/showthread.ph...29#post1582629

[LigH]

Yes, ffmpeg's AC3 encoder developed a bit since that AC3Enc plugin for BeSweet.

Interleaving the six channels to a 6-channel file may pass the 4 GB limit, therefore the W64 target is recommendable. The usual WAV header has only 32 bit size fields in their chunks.

[Joniii]

Question about RAW/PCM channel remapping. If I demux RAW/PCM from Blu-ray to RAW, eac3to swaps endian and remaps channels. If I later mux that RAW to Blu-ray M2TS with tsMuxeR, wouldn't I then have wrong channel order?

Oh, and second question if anyone here has some ideas. What would be the best way to join The Lord of The Rings EE main movies as those are on two discs? I would like to get those to mkv.

[Shevek]

Originally Posted by Joniii

Oh, and second question if anyone here has some ideas. What would be the best way to join The Lord of The Rings EE main movies as those are on two discs? I would like to get those to mkv.

MKVMerge (and it's GUI) has an append function. Add part 1 video and audio then click the append button in the GUI to add part 2 video and audio

[Joniii]

Originally Posted by Shevek

MKVMerge (and it's GUI) has an append function. Add part 1 video and audio then click the append button in the GUI to add part 2 video and audio

Thx, I'll try that.

[Joniii]

Didn't work, playback got screwed where the files were joined also the playtime of the file was over 5 hours.

[manolito]

I have a long 6-ch AAC file which I want to convert to a 6-ch AC3 file. The source file has been created by Nero AAC encoder, here is the MediaInfo analysis:

Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format-Profil : LC
Codec-ID : 40
Dauer : 2h 19min
Bitraten-Modus : variabel
Bitrate : 321 Kbps
maximale Bitrate : 380 Kbps
Kanäle : 6 Kanäle
Kanal-Positionen : Front: L C R, Side: L R, LFE
Samplingrate : 48,0 KHz
Stream-Größe : 320 MiB (100%)
verwendete Encoder-Bibliothek : Nero AAC codec 1.5.4.0
Kodierungseinstellungen : -q 0.40
Kodierungs-Datum : UTC 2012-09-08 16:18:01
Tagging-Datum : UTC 2012-09-08 17:37:15

The file plays in all my software players. But eac3to somehow cannot be convinced to convert this file:

eac3to v3.24
command line: eac3to.exe i:\test.m4a i:\test.ac3
------------------------------------------------------------------------------
The format of the source file could not be detected. <ERROR>

Giving the file a different extension like .mp4 or .aac does not help either. What's wrong here?


Cheers
manolito

[tebasuna51]

To decode AAC with eac3to you need Nero 7 decoder installed (like say first post in this thread).

You can use Foobar2000 or BeHappy-BassAudio to recode AAC -> AC3 directly.
Or you can decode AAC to WAV (with Faad) and after use eac3to.

You can't change the extension of the file. A .aac file is AAC audio with ADTS headers. A .m4a file (mp4 with only audio) is AAC audio in mp4 container.

[manolito]

Thanks tebasuna for your quick reply.

Originally Posted by tebasuna51

To decode AAC with eac3to you need Nero 7 decoder installed (like say first post in this thread).

Sorry, I will certainly not install bloated software like Nero7 on my machine...
I have NeroAacDec in my eac3to folder though, and NeroAacDec can certainly decode my source file. Why in the world can't eac3to use NeroAacDec for decoding AAC files?

You can use Foobar2000 or BeHappy-BassAudio to recode AAC -> AC3 directly.
Or you can decode AAC to WAV (with Faad) and after use eac3to.

Yes, this will probably work, but frankly I am too lazy to learn using these programs (I read that BeHappy is a nightmare to set up) for just the simple task to transcode AAC to AC3.


Cheers
manolito

[sneaker_ger]

ffmpeg is fairly easy to use for this task:
ffmpeg -i input.m4a -ab 448k output.ac3

Sadly, eac3to cannot utilize neroaacdec.exe, nor can it handle AAC audio in mp4 container. (But ironically, it cannot create AAC audio without mp4 container...)

[manolito]

Thanks sneaker_ger,
I know that ffmpeg can make these conversions. Frankly I am a little worried about the quality. Do current ffmpeg versions use Aften for AC3 encoding? I could not detect "libaften" anywhere in a couple of recent binaries.

In the meantime I made my own little tool for AAC to AC3 conversions. It uses faad and Aften. Here is the readme:

AAC2AC3 - Simple audio conversion utility
-------------------------------------------

Converts AAC audio files to AC3 using FAAD and Aften.
Large multichannel files are supported.

Downmix of multichannel sources to stereo is supported,
also the encoding bitrate can be specified (CBR only).
Other effects like normalizing, DRC profiles or Dialog
Normalization are not supported.


Usage:
Use 'Drag and Drop' or 'Copy and Paste' to feed a source file
to the executable. A target file of the same name and the
extension .ac3 will be created in the source folder.


Known issues:
The executable is a compiled batch file. If your virus scanner
has a problem with it, file a complaint with the manufacturer...

For anyone interested, you can download it here:
http://www.sendspace.com/file/oxrf7s



Cheers
manolito

[sneaker_ger]

Aften is based on the ffmpeg encoder. I think that actually the ffmpeg one has had a few minor improvements while aften was already stalled.

[Boulder]

Has anyone tried to compile new avcodec.dll and avutil-50.dll to use with eac3to? I'm not sure if there have been any big changes but the ones used by eac3to are over 2 years old now.

[kypec]

Originally Posted by Boulder

Has anyone tried to compile new avcodec.dll and avutil-50.dll to use with eac3to? I'm not sure if there have been any big changes but the ones used by eac3to are over 2 years old now.

Few months ago I tried to replace those DLLs with newer versions - it didn't work.
madshi should have released this as open-source long time ago...

[Boulder]

The changes made by madshi are there in the "legal stuff" folder, so it should be possible to build new libraries. I was just wondering whether anyone's tried that out yet.

[sexconker]

Originally Posted by BugiBugBug

Then this is -very- weird, because every file I remux is out of sync. One worse than the other (two were completely unwatchable).
I did have problems with my hard drives - it seemed the AHCI modus used on my AMD SB700 rig caused some writing/reading errors, maybe some bits have been 'shifted around' without me knowing. It never told me though, untill I started getting errors of programs being corrupt and such. Now I reinstalled my rig in RAID mode (single discs), which allows the use of RAIDXpert, which monitors stuff like that. Who needs S.M.A.R.T. if it doesn't work...
Luckily I know now I did not do anything wrong out of stupidity...

I had a hell of a time dealing with a recent video.
I was using eac3to to convert the DTS-HD MA track to a 7.1 AAC (Arcsoft to Nero), and the audio would become progressively out of sync regardless of how I muxed it.

I tried all manner of fiddling / manually specifying the video framerate, but nothing worked. In the end (2 days of slamming my head against a wall), I ended up going with 5.1 instead of 7.1 and everything worked fine.

No idea what's up. Next job I do I'll post about it here if I have the same issue.

[nibus]

Originally Posted by Joniii

Didn't work, playback got screwed where the files were joined also the playtime of the file was over 5 hours.

There's a number of topics about LOTR EE and merging the discs. Do a forum or google search on it.

Basically you have to cut off the last few seconds of the end of part 1, and about 1 second from the beginning of part 2. You can do this in mkvmerge.

This is because the audio stream ends before the video stream.

[the_weirdo]

Originally Posted by Boulder

The changes made by madshi are there in the "legal stuff" folder, so it should be possible to build new libraries. I was just wondering whether anyone's tried that out yet.

Those patches are too old, some are even redundant (for example, libavcodec can now output AC-3 and DTS as floating point via API call), so I don't think they can be easily applied to latest libav* codebase. Also, there are a lot API/ABI changes in libav* during past 2 years, so even someone manage to apply those patches and build new libraries, I doubt they can be used with current eac3to.

Now only hope that Madshi will soon release madVR 1.0 then he can return to develop eac3to.