AC3 in MP4!

[bond]

This discussion will soon be over as a standard spec is currently in development for supporting ac3 (and eac3) in mp4

it will be annex f to the ac3 standard ETSI_TS_102_366

[Elias]

This discussion will soon be over as a standard spec is currently in development for supporting ac3 (and eac3) in mp4

it will be annex f to the ac3 standard ETSI_TS_102_366All right, that did it for me. Now I'm completely dropping mp4 and opting for Matroska. I see no reason to support mp4 after this. Not that I hope mp4 will die out or anything like that, I certainly prefer it over shitty avi, but it seems to me like the big companies that control mp4 just can't make up their minds, and they're not very good at sticking to the standards they've created. So might as well go Matroska all the way; it's open source and a lot more user friendly.

What's "eac3"?

[SeeMoreDigital]

What's "eac3"?They are Dolby Digital Plus streams.

They can be found on HD-DVD and Blu-ray movies, and offer upto 8 (7.1) audio channels...

[crypto]

...Until an AC3 muxer or consumer-level AAC decoding receiver is released, there's no hope of getting surround sound on an Apple TV. I already send 'feedback' to Apple regarding this, and its a widely known issue, but they have no incentive to fix anything because it just drives rentals of their movies rather than piracy.

Your info on Apple TV seems a bit out of date. Since Take 2 it officially supports AC3 in mp4, with an AAC fallback track. Apple is using it for all HD rentals. VLC is also supporting it and there is an open source muxer for it.

[SeeMoreDigital]

Your info on Apple TV seems a bit out of date. Since Take 2 it officially supports AC3 in mp4, with an AAC fallback track. Apple is using it for all HD rentals. VLC is also supporting it and there is an open source muxer for it.Anybody have any up-to date sample files?

[refulgentis]

Your info on Apple TV seems a bit out of date. Since Take 2 it officially supports AC3 in mp4, with an AAC fallback track. Apple is using it for all HD rentals. VLC is also supporting it and there is an open source muxer for it.
I know it supports AC3, that's why I'm asking how to put AC3 in an MP4 ;). There is no open source muxer for this according to the people over at handbrake (and the discussion forums for mp4box/mp4creator/ffmpeg), and if you've found one that puts AC3 in an MP4, please please please share.

[refulgentis]

Anybody have any up-to date sample files?SVN Handbrake will generate ones from a DVD, I'm not sure how to get one off an Apple TV because I believe HD + surround sound are only available in rental form on Apple TV.

[Kurtnoise]

if you've found one that puts AC3 in an MP4, please please please share.
:search:

[SeeMoreDigital]

SVN Handbrake will generate ones from a DVD, I'm not sure how to get one off an Apple TV because I believe HD + surround sound are only available in rental form on Apple TV.I've tried a few AC3 in MP4 samples muxed with Handbrake... They were very borked.

So far, Nero8's offerings appears to be the most stable.

[bond]

All right, that did it for me. Now I'm completely dropping mp4 and opting for Matroska. I see no reason to support mp4 after this. Not that I hope mp4 will die out or anything like that, I certainly prefer it over shitty avi, but it seems to me like the big companies that control mp4 just can't make up their minds, and they're not very good at sticking to the standards they've created. So might as well go Matroska all the way; it's open source and a lot more user friendly.

What's "eac3"?hm maybe you misunderstood the message. currently there is no clear standard for how to store ac3 in mp4, in the future there will be and thats a good thing

[crypto]

Ok, sample is up: sample-ac3.mov (http://pub.vftp.de/atv/sample-ac3.mov) 33.8MB

[SeeMoreDigital]

Ok, sample is up: sample-ac3.mov (http://pub.vftp.de/atv/sample-ac3.mov) 33.8MBBummer...

Sadly I'm unable to test that particular sample in my hardware player because the AAC track is flagged up before the AC3 track.

[refulgentis]

:search:
I assume you're referring to Recode 3? That's the only tool I'm aware of that will put AC3 in an MP4, and trust me, I've done more than enough :search: on this.

EDIT: my gosh, I've spent 8-10 hours a day the last 6 weeks doing research on getting a good MP4 to meet Quicktime's standards, and innumerable searches on AC3 MP4, and just now by going through your old post history I found http://forum.doom9.org/showthread.php?t=124175. Now I just have to install Windows :P

If anyone has a mp4box/mp4creator/ffmpeg patch that will hack this through, that's preferable of course.

[refulgentis]

Ok, sample is up: sample-ac3.mov (http://pub.vftp.de/atv/sample-ac3.mov) 33.8MB
Is that from Handbrake? And is it MP4? Looks like MOV to me.

[crypto]

Is that from Handbrake? And is it MP4? Looks like MOV to me.

Yes. To cut the sample, I used QT. Unfortunately, it can only save to MOV. Exporting to MP4 destroys the AC3 track. The original full-length stream however was MP4. Does the sample work for you? If not, I have to find a way to keep the MP4 format.

[refulgentis]

Yes. To cut the sample, I used QT. Unfortunately, it can only save to MOV. Exporting to MP4 destroys the AC3 track. The original full-length stream however was MP4. Does the sample work for you? If not, I have to find a way to keep the MP4 format.
Yeah it looks fine, just curious, I needed a sample by Handbrake to crosscheck how AC3 is described in Handbrake vs. gdsmux and having yours makes it easy.

[Drachir]

EDIT: my gosh, I've spent 8-10 hours a day the last 6 weeks doing research on getting a good MP4 to meet Quicktime's standards, and innumerable searches on AC3 MP4, and just now by going through your old post history I found http://forum.doom9.org/showthread.php?t=124175. Now I just have to install Windows :P


I doubt that files with ac3 audio, created by gdsmux, will have sound in Apple TV. Gdsmux is probably using a private ObjectTypeIndication (0xC0 - 0xE0, 0xE2 - 0xFE), a so called private stream.
I would use a private ObjectTypeIndication only for testing or internal use.

[crypto]

Yeah it looks fine, just curious, I needed a sample by Handbrake to crosscheck how AC3 is described in Handbrake vs. gdsmux and having yours makes it easy.

Handbrake uses libmp4v2 with a patch. You can probably use their patched library with mp4creator. For details on the patch, have a look here (http://forum.handbrake.fr/viewtopic.php?f=4&t=4726).

[refulgentis]

Handbrake uses libmp4v2 with a patch. You can probably use their patched library with mp4creator. For details on the patch, have a look here (http://forum.handbrake.fr/viewtopic.php?f=4&t=4726).yeah, I already tried going that route (patching mp4creator), I was able to create the ac3 atom like them but I don't know how to read and write the actual stream to the mp4.

of course, I have only about 6 months of C/C++ programming experience from a silly high school class that was self-guided and no experience with AC3.

i'm hoping someone who has that experience will step up to do that. the handbrake developer who patched libmp4v2 basically said he's busy enough and not interested in patching mp4creator.

[refulgentis]

I doubt that files with ac3 audio, created by gdsmux, will have sound in Apple TV. Gdsmux is probably using a private ObjectTypeIndication (0xC0 - 0xE0, 0xE2 - 0xFE), a so called private stream.
I would use a private ObjectTypeIndication only for testing or internal use.
yeah, I really doubt it will work, but I guess its worth a shot

[SeeMoreDigital]

Yes. To cut the sample, I used QT. Unfortunately, it can only save to MOV. Exporting to MP4 destroys the AC3 track. The original full-length stream however was MP4. Does the sample work for you? If not, I have to find a way to keep the MP4 format.Interesting... Are you able to cut the sample and remove the AAC audio track. Leaving just the AVC video and AC3 audio streams within .MOV?

[crypto]

Interesting... Are you able to cut the sample and remove the AAC audio track. Leaving just the AVC video and AC3 audio streams within .MOV?
Sure, that's simple. If you have QT Pro, open the movie properties, select the stereo track and click delete. Then save the movie.

QT edit functions work ok on this sample, because all tracks are correctly muxed. Have a look at the video track. It has a data size and data rate. As long as that is ok,
iIt is even possible to add an AC3 track in QT.

This is not the case when you mux using mp4box and its derivates. As a result editing in QT is not possible, due to the missing video track data size resp. data rate.

[SeeMoreDigital]

Thanks Crypto,

I've just updated QuickTime Pro to version 7.4.5... And now I can open and edit .MOV files with AC3 audio :)


Many thanks

[Ranguvar]

Alright, I'm going to beg everyone here :p

I'd really like to be able to mux MP4's containing both stereo AAC-LC audio (for compatibility with my PS3 and 360), and AC3 5.1. I know HandBrake generates MP4's that can be played in the 360 and PS3 like that, but gdsmux.exe does not work, it creates videos that cannot be played by the 360. And I'd rather not use HandBrake; I prefer to do my video encoding through x264.exe and AviSynth.

So, I'd really love it if somebody could build a working mp4creator with the patch. I have very little experienced in building like this, and the MPEG4IP page warns everyone that Windows builds will most likely crash and burn. So, if a kind soul could perform this task... :)

[SeeMoreDigital]

So, I'd really love it if somebody could build a working mp4creator with the patch. I have very little experienced in building like this, and the MPEG4IP page warns everyone that Windows builds will most likely crash and burn. So, if a kind soul could perform this task... :)How about getting involved in the testing of Crypto's new application: -

http://forum.doom9.org/showthread.php?t=138445

[jult]

OK, so I've read this topic and I'm still not certain if it's a good idea to mux ac3 into mp4.
Point is:
I have a lot of AVCHD files from camcorders, they have AC3 audio (256 kbit/s @ 48 kHz) in them, just two channels audio.
It's pretty sad to have to transcode audio again and again, especially if the target is not much different (with regards to bitrate). I currently decode to wav using:
azid --maximize --stereo=stereo --filetype=wav_float
and then encode the wav using:
neroAacEnc -q 0.62
but I'd much rather mux the original .ac3 I demuxed from the .mts file.

Any ideas on that?

[SeeMoreDigital]

Are you re-encoding the AVCHD camcorder captures to a lower bit-rate?

[jult]

Yes, the source is 17 Mbit/s (!) blu-ray level quality. So the video can be downsized for some purposes. Audio is not that good to begin with (from this cam) so I'd like to retain source-quality as much as possible.

I use x264 and avisynth for the video and mp4box to mux it.

[SeeMoreDigital]

I see...

Personally I would hold-off muxing AC3 audio into the .MP4 container until the official (MPEG-4 ISO/IEC) specification for doing so is released... Which should not be much longer.

Until then, I'd recommend muxing AVC video with AC3 audio into either the .TS or .M2TS container, using TSmuxer GUI.


Cheers

[jult]

Until then, I'd recommend muxing AVC video with AC3 audio into either the .TS or .M2TS container, using TSmuxer GUI.Is there a non-GUI way to use TSmuxer? I'm scripting the process, so what I do now is:

for %%a in ("*.h264") do mp4box -add "%%a" -add "%%~na.aac" -fps 25.00 -new "%%~na.mp4"

in a batch-file. I'd like to do similar with TSmuxer. Maybe it's just there, I haven't even looked at TSmuxer yet.

Thanks for the hint!

[crypto]

jult, you can mux AC3 into MOV using Quicktime Pro, but that would not save you from encoding audio to AAC. An AAC fallback track is mandatory. Not all players know how to use the AC3 track. BTW. Which player are you going to use?

[jult]

I'm definitely not ever in my lifetime encoding to mov, sorry.

Players are many, but it needs to be Quicktime compatible.

[crypto]

I'm definitely not ever in my lifetime encoding to mov, sorry...
Ok, fair enough.

[bond]

ok, the official ac3-in-mp4 specs are publically mentioned (after being mentioned on doom9 of course ;) ):

http://www.mp4ra.org/specs.html

"ETSI TS 102 366 v1.2.1 - Digital Audio Compression (AC-3, Enhanced AC-3) Standard, Annex F"

how to place ac3 in mp4 will be described in annex f to the official ac3 standard

its not yet publically available on the net (at least i didnt find it)

and, word is, nero will switch to this standard as soon as its offical. good thing, nero!

[mediator]

nero will switch to this standard as soon as its offical

@bond: wow! you are _really_ fast ;)

[Ranguvar]

Nice! Now it remains to be seen whether DivX's MKV support or Nero's MP4 support will carry the day... I personally think it will be MKV, which is good IMO because MKV has more features and more formats supported, but we'll see.

[SeeMoreDigital]

and, word is, nero will switch to this standard as soon as its offical. good thing, nero!When this happens, hopefully it wont take long for the handful of hardware player manufacturers who already support NeroDigital's AC3 in .MP4 to update their chip-sets firmware...

[mediator]

the wait is over. The updated ETSI TS 102 366 including Annex F is published.

[SeeMoreDigital]

the wait is over. The updated ETSI TS 102 366 including Annex F is published.Hi mediator,

Do you know how quickly Nero will be updating to the revised spec for placing AC3 within .MP4?

Will you be able to provide samples for testing in hardware players?


Cheers

[mediator]

Do you know how quickly Nero will be updating to the revised spec for placing AC3 within .MP4?

For playback, support is going to be released as quick as the release cycle allows (which unfortunately isn't tomorrow ;)). For Recode, this is currently being figured out.


Will you be able to provide samples for testing in hardware players?

Not right now. But hardware players supporting this don't exist either (right now).

[Ritsuka]

Interesting, the specification in ETSI TS 102 366 is the same that apple uses for the appletv.

[mediator]

Interesting, the specification in ETSI TS 102 366 is the same that apple uses for the appletv.

not exactly. ETSI doesn't use the "wave" box.

[Ritsuka]

Neither does Apple for MP4. Yes, ac-3 in MOV uses a totally different sample description. But we aren't talking about Mov here :)

[bond]

good stuff. any link to the new specs?

[crypto]

To get the specs (free after registration), query then ETSI library at: http://pda.etsi.org/pda/queryform.asp
I used the search term "TS 102 366" (without quotes)

Search result:
ETSI TS 102 366 V1.2.1 (2008-08) Latest document information Download
Reference:RTS/JTC-019 Source:BROADCAS 1295627 bytes (214 Pages) Former price code: R
Title: Digital Audio Compression (AC-3, Enhanced AC-3) Standard

@bond
I found no differences to the prerelease annex f document.

[sethk]

Will the 360 and / or PS3 be able to playback MP4 files with AC3 that follow the updated standard (with their current software)?

[Ranguvar]

I'm going to guess no... but I have high hopes that since Sony is partnering with DivX to provide the MPEG-4 ASP decoder for the PS3, they will support the DivX H.264 profiles too soon, which means MKV and AC3 support on the PS3. And if they do it, it'll put heavy pressure on MS to do it as well for the 360.

[bond]

To get the specs (free after registration), query then ETSI library at: http://pda.etsi.org/pda/queryform.asp
I used the search term "TS 102 366" (without quotes)

Search result:
ETSI TS 102 366 V1.2.1 (2008-08) Latest document information Download
Reference:RTS/JTC-019 Source:BROADCAS 1295627 bytes (214 Pages) Former price code: R
Title: Digital Audio Compression (AC-3, Enhanced AC-3) Standard

@bond
I found no differences to the prerelease annex f document.:thanks:
is it realistic for you to write a patch for mp4creator supporting ac3?

[crypto]

:thanks:
is it realistic for you to write a patch for mp4creator supporting ac3?
Yes, that's the plan.

[Kurtnoise]

Just let you know that FFmpeg is now able to mux AC3 (& dirac too) streams in mp4/mov/m4v files since revision 15184...

Not tested yet though.


@Bond: it's time to update the FAQ, isn't it ? :p