How to convert 5 ch. AC3 to 5 ch. MPEG-2 Layer II

[macman241]

Hi,

I'm trying to conevrt a 5 channel AC3 audio file into a 5 channel MPEG-2 Layer II, but can't seem to be able to find the proper tool to do it.

Can somebody please let me know if such tool exists?

Thanks in advance and regards!

[guns1inger]

These might help :

http://www.stud.uni-siegen.de/sven.koelsch/mpeg2mc/
http://sourceforge.net/projects/mctoolame/

[macman241]

Thanks! This looks like what I'm after. Any idea where I can fine a compiled version of the mctoolame as their site only has the source for download and I'm not sure how to compile that.

Thanks again!

[aedipuss]

what's the audio for? there are different standards.

[jman98]

I want to warn you that almost nothing can correctly play multichannel MPEG audio. I live in the USA and I have yet to find an amplifier that's able to correctly process a multichannel MPEG audio signal. Most amps only play the signal in stereo because 5.1 MPEG audio is compatible with MPEG stereo sound. I have a DVD from Australia with 5.1 MPEG audio and I've never been able to play it as anything but stereo. Even Philips has abandoned the format. I don't think a DVD has been made in years with multichannel MPEG audio. I have a Philips DVD player and I don't know if the problem is that my player can't correct send a multichannel MPEG signal to my amp or if the amp is unable to decode it as a multichannel signal.

Years ago when DVD burners were really expensive, I was working with SVCD and I created a test SVCD with 5.1 MPEG audio on it using some guides I found on the internet. Some of the tools you have to use only work on Linux, so if you don't have access to a Linux system, you are wasting your time.

[Cornucopia]

Hypercube Transcoder. Easiest method by far.

I would agree with jman98's warning though.

Scott

[jman98]

I never heard of Hypercube Transcoder, but I would most strongly suggest you use that rather than attempt to do it the very cumbersome way that a link in guns1inger's post talks about which require the use of Linux.

[macman241]

what's the audio for? there are different standards.

Here's what I'm thinking: I've got lots of high-quality MKV movies with either AC3 or DTS sound. I'd like to be able to play them on PS3 (yes, PlayStaion 3). It is quite easy to demux/remux the MKV into a MP4 container, problem is that the PS3 will not play a multi channel AAC audio. As the MPEG-4 format allows for having the audio in an MPEG Layer 2 format I'd like to try to transcode the AC3/DTS into a multi channel MPEG audio and then mux it with the h.264 video.

So far, the video plays fine, but I've only managed to transcode the AC3 to either multi channel WAV/AIF (PCM). The PS3 would play the multi channel WAV, but only via HDMI 1.3 capable receiver. Through the digital audio output it will downsample to 2 channel PCM.

So, if anyone has done this or thinks about trying it out, would ba happy to do some work together..

[jman98]

I would bet almost anything that the PS3 will NOT be able to correctly pass a multichannel MPEG audio file to anything and will only output stereo. Don't be surprised if this doesn't work like you hope.

Is there a reason why the PS3 will not support AC3/DTS in an MP4 container? I don't think the MP4 container refuses to let you use AC3/DTS, so if this is the real reason you want to do this, I would just remux your files into MP4 containers, leave everything alone, and I bet it plays fine. Maybe you have some bad information where someone only thinks the MP4 container requires certain types of audio files. In fact, it really shouldn't care at all what type of audio you have - WAV, MPEG, AAC, AC3, DTS, MP3, etc. should all be OK in terms of the container itself.

[Cornucopia]

IIRC, the MP4 container, much like it's cousin the MPEG2 Program Stream container, will support MP1, MP2, MP3, AC3, AAC, maybe DTS. It probably WON'T support WAV/LPCM for probably the same reason--those don't normally include a timecode stamp which is something that the container needs to keep sync. (That's why you can't mux a PCM/AIF/WAV in MPEG2, but you can in a VOB as it's a non-standard, über-program stream).

I agree with jman98, leave as-is if at all possible. Exhaust those possibilities first before trying MPEG2multichannel.

...or downconvert to ProLogic and encode to whatever filetype works best for you...

Scott

[guns1inger]

If you encode to multi-channel mpeg2 and pass it as a digital stream then your amp needs to be able to decode the stream again. The PS3 isn't going to do anything but send the data through. Both my DVD players will happily send a multi-channel mpeg-II bitstream through to an amp, but out here I have never seen an amp with multi-channel mpeg-II decoding.

[macman241]

I would bet almost anything that the PS3 will NOT be able to correctly pass a multichannel MPEG audio file to anything and will only output stereo. Don't be surprised if this doesn't work like you hope.

Is there a reason why the PS3 will not support AC3/DTS in an MP4 container? I don't think the MP4 container refuses to let you use AC3/DTS, so if this is the real reason you want to do this, I would just remux your files into MP4 containers, leave everything alone, and I bet it plays fine. Maybe you have some bad information where someone only thinks the MP4 container requires certain types of audio files. In fact, it really shouldn't care at all what type of audio you have - WAV, MPEG, AAC, AC3, DTS, MP3, etc. should all be OK in terms of the container itself.

I'm trying to use YAMB to mux the h.264 with the AC3 track but won't let me. It would only accept 2 ch AAC, MP3 or few other formats I haven't heard of (smv, evc, or amr).

What tool could I use to mux an h.264 with AC3 audio in an mp4 container?

[Nelson37]

Hypercube Transcoder is the only prog I have verified to be able to produce a valid, multichannel MPG-2 audio stream. IIRC, you have to convert the AC-3 to 6 WAV files and then convert that to MPEG-2 5.1.

While I have the equipment to decode and play such a stream, this is extremely rare, such that I have NEVER in over 5 years seen a single report of anyone else making and playing such a stream. Very few DVD players support it, and even fewer amps, and you have to have both.

I would say AC-3 would be your best bet for external playback amp.

[macman241]

Downloaded Hypercube Transcoder but it always freezes at 33.33%?! no matter what input/output files I specify...

[Nelson37]

I only actually used it once, on WAV files designed for testing. "This is left front, this is right rear", etc. Made the disk several years ago and only recently acquired equipment able to play the disk, a Phillips integrated DVD, amp, and speaker unit. It was on sale.

Unfortunately, I did not test the prog further because at the time, I could not use the output and now that I can, I don't make SVCD anymore.

Only things I could suggest is make sure WAV files are NOT VBR, no compression, verify file integrity, and again start with 6 WAV files and NOT an AC-3 or other compressed file.

What file type are you starting with and what does the program appear to be doing at the 1/3 mark where it fails?

Also, while this is interesting, you almost certainly will not get 5.1 sound output unless you run it through a Phillips amp, I have never heard of any other brand which supports this. So this effort may yield some interesting info, but most likely no useful results.

I do a lot of this kind of stuff, will be glad to help if I can, testing, sample files, etc. Also I have SFAIK the only working equipment known to this board to test such an audio file, can play a file from a USB stick, so verification of correct playback is available to you.

[aedipuss]

here the method i used many times to create 5.1 multichannel mpg for svcds i made. note the 44.1 not 48khz dvd spec output.

to convert 6 channel ac3 stream into mpeg2multichannel stream

you need the following tools.

phillips encoder(pub_enc.exe) - http://www.licensing.philips.com/ordering/soft/documents343.html
download the mpeg audio tools zip at the bottom of the page. unzip tools and tables - make tables a subdirectory of the pub_enc.exe folder

BeSweet - http://dspguru.doom9.org/

make sure to use a 6ch ac3 file as input.ac3

here are the two commandlines :

use the besweet commandline version only - fill in proper directories for files.
BeSweet -core( -input input.ac3 -output inter.aif -6chaiff ) -ssrc( --rate 44100 ) -ota( -g max )

pub_enc is a directory sensitive dos program run from it's dir.
pub_enc -l 2 -m s -n d -r 44.1 -b 384 -L -p 3 -e -v 0 inter.aif final


be aware that the inter.aif file can be 5 or 6 GB in size.

the resulting file will be final.mpg which is a mpeg2multichannel stream.

[macman241]

aedipuss - many thanks for the tips and the offer. Looks like however Philips have removed all of those mpeg-related pages and I can't find their tool. Greatful if you could provide a pointer to where it may be available.

thanks in advance and regards!

[aedipuss]

sorry that's part of a 5.1 svcd guide i wrote for Dr. Mercury and his svcd site many years ago and it seems phillips has "updated" their site and good ole doc's site went down a few years ago. i have the program but no way to legally give it to anyone as i don't know it's copywrite status.

[aedipuss]

ok. i found the original zip and the readme file. don't know exactly what it means but i does say it's based on public programs and provided as is....

The tools.zip archive contains some WIN32 tools supporting the development
of applications according to the MPEG )|( Multichannel spec.

Specific MPEG tools:
--------------------

pub_dec.exe 7.1 channel decoder based on the dist10 public MPEG software
pub_enc.exe 7.1 channel encoder based on the dist10 public MPEG software

and

Terms and Conditions


Philips Consumer Electronics B.V., Advanced Systems and Applications Laboratory
and having its principal place of business at Eindhoven, The Netherlands (hereinafter
referred to as "Philips")

The CD-ROM with MPEG streams from the MPEG-empowered test-suite, streams from the
LVP08 disc, and a couple of software tools (executables) are provided on an "as is"
basis for test purposes only, without any warranty whatsoever, whether express,
implied or otherwise, regarding its accuracy, completeness or otherwise, and Philips
shall not be liable for any direct, special, incidental, consequential or other damages.


if the guys here want to host it i could give it to them?

[Nelson37]

I'm pretty sure the Phillips software was either placed in the public domain or was originally given away for free. I've got the whole VCD creation set somewhere, never used it as the demo disk showing all the features revealed that my DVD player did not support most of them. Impressive what VCD menus could achieve.

Aedipuss, what hardware are you using for playback?

[aedipuss]

the dvd player is a apex ad-1500 flashed with with austrian ad-1200 firmware with a sony 7.1 amp. the 5.1 svcds i made sounded better than normal svcd surround but i don't think the sony was actually outputting discrete rear channels. back the 6 or so years ago we were playing with them i posted quite a few on usenet and no one in the u.s. ever reported success in getting true 5.1 audio. not to mention just how hard the process was to produce them. i-author is the only muxing program that will make a working one and it's got more quirks than you can believe.

[Riki Chang]

I have a problem with pub_enc.exe. Revision: 2.5 990316
whatever arguments I have enabled, nothing happens - only white noise!
to the input: 6ch. PCM-wav, or mono PCM-wav, or simple PCM, 44100 or 48000.
anyway - only white noise or silence. And the .mpg file coded without windows-headers, only raw-stream and up to 2 times longer than original.

were used arguments:

pub_enc.exe -md -nd -e -L
pub_enc.exe -l2 -ms -nd -r44.1 -b384 -L -p3 -e -v0
pub_enc.exe -ms -ns -L -r44.1 -e -p3 -b320

nothing , don't work.
and on the argument "-n" it absolutely not reacts!
writes: Stereo: 1
Surround: 0

what's wrong?