Extract Audio from SVCD and convert from Stereo to 5.1

[Hotskillz]

I realize that there is no way to make 2 channels into 5.1 channels however I would like to upmix the to channels so that it just pipes the 2 channels through 5, basically go from Stereo to Dolby ProLogic. What programs would I need to A) extract the audio from the SVCD mpeg file and then b) how can I upmix the audio?

Thanks

[chazzie]

First of all, Dolby ProLogic does only use 2 channels, if you use 5.1 it's Dolby Digital. You can upmix it to 5.1 DD, but you would basically only get the same sound from the Front Right - Surround Right / Front Left - Surround Left. You have no reason to upmix it to 5.1 since it won't make a difference (i.e you won't hear a car fading to the left behind you because that data doesn't exist in the stream).

If you're putting that movie on DVD my tip is:
Video: 352x480(576) MPEG-2 @ 3000-3500 kbit/sec
Audio: Dolby Digital 2.0 @ 224 kbit/sec (or 192 kbit sec)

You could ofcourse also use MPEG audio, but in this case there would be no difference...

[Donny661]

Dolby Pro-Logic I/II is 4/5 channel sound (hidden) in a stereo track. There is a little extra inaudible information there for a decoder to use to separate the stereo track into 4 or 5 channels. You could, in theory, use a Pro-Logic I or II encoded stereo track to make a Dolby Digital 5.1 track (only 4 or 5 of those channels would be "real"), but I don't know of a program that would do this. Also, the only reason you would want to do this would be if your playing equitment wasn't set up for Dolby Pro-Logic but was for Dolby Digital.

[BJ_M]

plus you would lose so much quality re-encoding ..

[chazzie]

Dolby Pro-Logic I/II is 4/5 channel sound (hidden) in a stereo track. There is a little extra inaudible information there for a decoder to use to separate the stereo track into 4 or 5 channels. You could, in theory, use a Pro-Logic I or II encoded stereo track to make a Dolby Digital 5.1 track (only 4 or 5 of those channels would be "real"), but I don't know of a program that would do this. Also, the only reason you would want to do this would be if your playing equitment wasn't set up for Dolby Pro-Logic but was for Dolby Digital.

True, but it only USES 2 channels, that's why it was so good in backward compability back in the VHS era =)

[diddyk]

ok first off why would someone reply to a post if they don't have an answer and only tell you there is no reason to do what your trying to do? You obviously have a reason or you wouldn't have asked. I on the other hand will try and help you out with your problem. You can use Sonic Foundry Soft Encode to produce a 6 channel ac3 trac which is 5.1 dd all you have to do is load a 2 channel wav file 3 times and convert. Hope I was some help and good luck.

[BJ_M]

diddyk - i guess you missed the part about the fact that ac3 is a lossy format and to re-encode it you would lose quality -- to no gain what so ever ..

a better choice is to use your receiver and pick a setting which makes a fake surround out of 2/0 .. it most likely will sound better ..

also your method would end up with a left or right only channel in the center mix position which would cause the sound to pan heavy to one side ..

i have in the past given (as others) the correct remix settings for 2/0 to 5:1 if so wanting to do so .. a search on this forum should turn it up pretty quick ..

[diddyk]

I use soft encode and I have no problems what so ever and it sounds great doesnt pan heavy to either side. When I watch top gun Or fast and the furious when the cars and jets go by I hear them fly past and it sounds awsome. I dont know what the reason others want to re-encode audio only mine but they must have some reason for asking.