DOLBY DIGITAL AC3 TO MPEG-2 MULTICHANNEL

[Erwin Meulman]

[yg1968]

I got the impression that nobody uses the 6 channels mpeg audio format because DVD-Video players generally do not support it.

[MoovyGuy]

I got the impression that nobody uses the 6 channels mpeg audio format because DVD-Video players generally do not support it.

Hey yg1968 -- How ya doin ..

Actually Dolby Digital 5.1 is carried on 6 channels.

Erwin Meulman's command line is indeed correct, but there is also a proggie that you can get from www.Doom9.org that gives a nice GUI to BeSweet for doing this ... It's called HeadAC3he, latest ver is 2.3a. Using it all the time when I make DVD's an I have to downsample an AC3 track.

[yg1968]

Hi MoovyGuy,

What I meant is that converting AC3 into mpeg-2 audio will only be played as a stereo file unless your DVD player can play mpeg-2 audio. Most players can only handle mpeg-1 audio.

[MoovyGuy]

Hi MoovyGuy,

What I meant that converting AC3 into mpeg-2 audio will only be played as a stereo file unless your DVD player can play mpeg-2 audio. Most players can only handle mpeg-1 audio.

Surround sound is encoded into the left & right stereo channels. A DVD player would have to indeed have the appropriate decoder in order to play back the surround info, but most modern DVD players can ...

Just as a DVD player that can play back VCD or SVCD can play back MP2 as it is the standard for those formats, so the DVD player has the inherent ability. The SVCD standard does allow for surround sound encoded within the Stereo channels, so if you have a DVD player that can play SVCD you should be OK ...

Other players will simply play it at stereo ......

[yg1968]

In other words, you are going from Dolby Digital (5.1) to surround sound. Why would you do that if you are burning to a DVD?

P.S. The title of this thread is a bit misleading since it speaks of encoding to mpeg-2 multi-channel (i.e. six channels audio) whereas you are actually encoding to mpeg-1, layer II surround sound.

[MoovyGuy]

In orther words, you are going from Dolby Digital (5.1) to surround sound. Why would you do that if you are burning to a DVD?

To reduce the size of the audio track .... (leaving more room for video)

I don't have a good AC3 transcoder that can preserve the 5.1 nature of the track and reduce the bit rate.

AC3machine, using BeSweet, claims to be able to do this but all of the AC3 tracks that I produce with this combo have subtle errors that crash my DVD players.

I downsample to MP2 surround only if there will not be enough room to mux the original AC3 track with the Mpeg2 video track(s).

So downsampling to MP2 at least allows me to keep surround sound info. Not ideal, but better than nothing ,..

[ralfbeckers]

MPEG Layer II does indeed optionally support true multi channel sound. THis is what Philips wanted to force on the European users years ago when DVD was introduced here.

Anyway, you CAN make a SVCD with MP II multi channel using the DVD2SVCD program package available through the link page here.

Beware: The hardware support for MPEG MC is limited both in terms of players passing the entire data stream and decoders.

It is also true that MPEG MC does contain the front left and right channels in Lt Rt format. This means that any hardware decoder is backwards compatible if it can only "see" the stereo signal. You then can engage Dolby Surround decoding.

The essence is that you should only burn your SVCDs in MPEG MC if your home theater has the capability to play this. Otherwise you are just wasting bandwidth at the cost of video.

My system does support MPEG MC and the sound is simply amazing, just as the original. I use the 384 kbps data rate for audio. My player is a Digatron Mini-2001 and my decoder is a Sony TA-E9000ES.

Greetings,
Ralf

[yg1968]

You are confusing mpeg-2 audio with mpeg-1, layer II audio. Only mpeg-2 audio is multichannel (5.1 or 7.1). Philips introduced multichannel mpeg-2 audio. Mpeg 1 only uses 2 channels. Surround sound encodes 4 channels into a stereo channels but technically it isn't multichannel as it is carried on two audio tracks.

http://www.mpegaudio.philips.com/html/faq.html
http://www.dolby.com/company/is.ot.0011.TechOverview.05.html#s5a

[THE RIPPER]

if you had a dvd player that supported dvd-audio, perhaps it would play.