AAC AC3 question

[DigitalDivide]

Hi guys it's been a long 5 days waiting to finally post!

I'm new to the whole x264 thing and have one question. I've done some searching but I haven't found anything that specifically answers the question. Is it possible to encode into mp4 but keep the AC3 stream without converting it to AAC? If I play an AAC stream on my pc it gets converted to Pro Logic at the receiver. I really want to keep my AC3 sound.

I currently using GKNOT and encode using x264 which gives me the ability to keep my AC3, but the file is an avi. Can Megui do the above with the AC3?

On a side note, I tried the high quality setting for AVC by DeathbySheep. I started at 9pm last night and this morning at 7:30am it was ony 40% done. I have an Intel 2.8GHZ CPU. Using the default settings it took about 8hrs. It's kinda odd that Nero Recode can do it in half the time.

Thanks

[cuban]

I guess the answer is no. You can only keep mpeg standard streams in mp4 container. MP4 audio formats:
Advanced Audio Coding (AAC): Quicktime/iTunes, Nero, Psytel, FAAC... and MP3, MP2, MP1, CELP (speech), TwinVQ (very low bitrates), SAOL (midi), ALS (lossless).

If You want AC3 You will have to stick to Matroska or Ogm container (well, You can try avi too)

P.S. If the answer is yes (maybe it's possible, like ac3 in avi) it wouldn't be a mpeg4 compilant stream anymore.

[DigitalDivide]

Thanks Cuban,

Just curious, I don't know much about Matroska but would it be beneficial for me to move from avi to Matroska? The more I read the more confused I'm getting. Also any idea if Theatertek would play the outputed file or would I simply need FFDSHOW with TT and I should be fine?

[SeeMoreDigital]

Technically it is possible to place AC3 audio streams within the .MP4 container, as the MPEG-4 ISO/IEE standard allows the use of "Private Streams" within .MP4

It is after-all this standard that has allowed Apple to place their "lossless audio" streams within the .MP4 container as a private stream :)

That said, don't hold your breath for AC3 audio to appear within .MP4 anytime soon as it's generally accepted to be a bad idea!

If your DSS amp has 6Ch analogue inputs, you can connect to these.... This is what I do!


Cheers

[DigitalDivide]

SeeMoreDigital, I have a Yamaha Receiver which I don't believe has 6channel inputs.

Just curious, will the new "HD"format dvd's such as Blue Ray be using AAC for audio? I can't believe they would do that. Everyone who has a Receiver with DD or DTS would become useless, no?

[berrinam]

The change will have to happen eventually, otherwise we will be perpetually stuck with AC3 and DTS

[SeeMoreDigital]

....And don't forget Dolby have announced a new version of their surround sound format called DolbyDigital Plus, which offers 7.1 (or more) discrete channels. DTS have also announced a new version of their surround sound sound format, which I think is called DTS++

There will be MLP Lossless too, which is said to offer "discrete multichannel reproduction beyond present 5.1 or 7.1 applications".

So yes.... it looks like we'll all need to go out and buy new surround sound amps at some time....

Me also thinks that by the time Blu-ray and DVD-HD players reach us (in their fullest technical glory), we will only be able to listen to the new audio formats via an HDMI (with HDCP) connection anyway :(


Cheers

[lineman]

Hi guys it's been a long 5 days waiting to finally post!

I'm new to the whole x264 thing and have one question. I've done some searching but I haven't found anything that specifically answers the question. Is it possible to encode into mp4 but keep the AC3 stream without converting it to AAC? If I play an AAC stream on my pc it gets converted to Pro Logic at the receiver. I really want to keep my AC3 sound.

I currently using GKNOT and encode using x264 which gives me the ability to keep my AC3, but the file is an avi. Can Megui do the above with the AC3?

On a side note, I tried the high quality setting for AVC by DeathbySheep. I started at 9pm last night and this morning at 7:30am it was ony 40% done. I have an Intel 2.8GHZ CPU. Using the default settings it took about 8hrs. It's kinda odd that Nero Recode can do it in half the time.

Thanks
I am also looking for a mp4 and ac3 solution. I would like to use Nero Recode2 to make the video and then mux the original ac3 5.1 audio track and nero video together. The reason for this is because I have a Linkplayer2 and it will not play aac 6 channel audio, only 2 channel. I am not sure if there is a solution, can anyone point me in the right direction. Thanks
Lineman

[bond]

ac3 doesnt belong into .mp4

use .mkv or .avi for that

[lineman]

ac3 doesnt belong into .mp4

use .mkv or .avi for that

Thanks Bond
So is there a way of muxing the NERO mp4 (video only) stream with an AC3 into an AVI container? I have been unable to find a muxer that can accomplish this task. I usually use XVID but I find NERO faster and the video quality is a bit better. I might be looking for the ultimate solution...if its not possible...I will continue to use XVID.

Thanks

Lineman

[SeeMoreDigital]

With Buffalo and I-O DATA both manufacturing players that were unable to output 6Ch AAC audio (and WMAPro) correctly... I feel was a massive cock-up and should never been allowed to happen!

Fortunately, this oversight have been put right on the Zensonic Z500..... But it's worth reminding people to: -

"Always look at the connections on the rear of the player..... And make sure there are 6No analogue (RCA/Phono) audio outputs"!

With regard to muxing MPEG-4 with AC3 in AVI.... how about using AVI-Mux (http://www-user.tu-chemnitz.de/~noe/Video-Zeug/AVIMux%20GUI/index-eng.html).


Cheers

[stephanV]

AVIMux GUI doesnt support MP4 input.

If its ASP, it should be possible to mux the video stream into AVI with graphedit (but maybe some tool from GPAC can do this too? I remember mp42avi or something...). Then add AC3 with AVIMux GUI.

[SeeMoreDigital]

Yes, but it's possible to de-mux MPEG-4 SP/ASP video streams out of the .MP4 container using say mp4UI. And YAMB can do it to if you change "-raw" to "-avi" in the command line!


Cheers