Muxing AVC with AC3 - any way?

[JK1974]

Hi,

I did some tests with Nero Digital with HDTV material (HD1 from Astra satellite deinterlaced and downscaled to 1280x720) and I am really impressed of the image quality especially at low bitrates like 4 MBit/s - this would allow me to save current HDTV movies (like the ones transmitted in german ProSieben TV next week) on one DVD in good quality (there I could even use up to around 5,5 MBit/s).

But there is one thing I don´t like with Nero Recode: It uses AAC as audio codec. Although this is MPEG-4 compliant, I haven´t found any information that Blu-ray and HD-DVD are going to support it.
Dolby Digital IS supported, and as the movies are transmitted with DD 5.1, so it also does not make sense to transcode it as you loose quality.

But: Is there any way to mux MP4 AVC video with AC3 audio in a compatible way that allows me to play the video back with most common players (e.g. VLC if it support the full AVC features, Mplayer [linux], Nero ShowTime or even PowerDVD/WinDVD with DirectShow filters)? Matroska might be the solution (still have not taken a closer look) but still is not supported too well, isn´t it?

I want to be as Blu-ray/HD-DVD-compatible as possible, because I believe to have a video beamer in the next years as well as a Blu-ray/HD-DVD writer in the following 2-3 years. So I would have HDTV material for testing the beamer right from the start - neither based on a proprietary solution, nor with having the need to reencode it time-consuming if I want to play it from disc.

I know this is rather futuristic, but with this broadcasts I/we have (legal) access to european/german HDTV material for the first time which IMHO is really fascinating.

With kind regards

Joerg

[kurt]

Originally posted by JK1974
Matroska might be the solution (still have not taken a closer look) but still is not supported too well, isn´t it?

if you want to use ac3 with avc-video then use matroska - it supports avc very well... decoding works with latest ffdshow-builds and Haali-splitter (or nero splitter) in all directshow-players...

[iapir]

The question is more : what container will HD-DVD/Blue Ray support ? Since DD 5.1 is supported and AVC too, the combination will probably be supported... But using what container ? No idea. So as an interim solution (and less reencoding needed) Matroska should be the solution you're looking for.

[JK1974]

Thanks, I exspected this result. But you are right: As long I can demux it, I will not run later into compatiblity troubles.

It is said in the MP4 FAQ, that Blu-ray will support the MPEG-1/-2 container. Additionally, CyberLink PowerEncoder AVC, that claims to be Blu-ray/HD-DVD ready, also uses this container format to mux AVC with MP2 (not AAC, but MPEG1-Layer2 audio). But I also haven´t seen any MPEG-1/-2 muxer that already supports muxing MP4 (and demuxing later on).

[bond]

just my two cents:
- hd-dvd will not use ac3 (it will support DolbyDigital+, which is different to the ac3 we use today, but i dunno if its backwards compatible)
- noone knows how streams have to be encoded for being compliant to hd-dvd, so with a propability of 99.9% streams created today will not be 100% compliant to hd-dvd ;)
- some bluray docs talk about using MPG Transport Streams (TS) as container, which is not the most of the time used .mpg (aka PS)
- there is still no info available about which container hd-dvd will use
- there is no way to place ac3 in .mp4 and even if there where one i wouldnt use it
- ac3 and avc should be muxeable into .avi, .ogm and matroska. i would prefer matroska while storing avc "natively" (as doable in mkvmerge) not in the avi/vfw compatibility mode

[JK1974]

Hi,

there is an updated white paper on blu-ray disc at www.blu-raydisc.com (http://www.blu-raydisc.com), which says, that AVC and AC3 will definately be part of the blu-ray disc standard. Additionally, Nero themselves claimed at CeBIT that they create standard conform streams. Nevertheless, AAC has not been taken into the blu-ray specifications. VC-1 also will be part of the standard, while Windows Media Audio will not.
That are 2 reasons to take the Matroska container format because the Windows Media Encoder does not allow to use any other audio output format than Windows Media Audio - or you take an AVI container and VirtualDubMod, but this is not my favourite way to go...

[lazyn00b]

JK1974, although AAC is not mentioned in the spec for pre-recorded BD-ROM, the BD-RE (Rewritable) spec explicitly mentions support for Japanese BS streams, which implies AAC support. I imagine that this means that any Blu-Ray player certified to play BD-RE will have to be able to decode AAC as well. I would hope that such players, at least those intended for the Japanese market, would also be able to pass-through AAC via SPDIF for those Japanese home theater receivers that are already able to decode AAC streams.