music to 6ch flac

[nixiejames]

i just downloaded aimp and i noticed it has an option to convert tracks to flac 5.1 surround.

i backed up my original cds to flac and i was wondering if there is a point or reason for someone to convert his collection of lossless stereo music to 6ch flac.

and i also want to know if it remains lossless afterwards.

[El Heggunte]

1) no point

2) it's not lossless. Stereo to 5.1 means «adding information that did not exist in the source files».

[pandy]

Stereo to 5.1 means «adding information that did not exist in the source files».

I think from formal perspective this will be more like interpreting information in a different way...

[Cornucopia]

I think from formal perspective this will be more like interpreting information in a different way...

Only theoretically, or going something esoteric like Binaural (or Ambisonic UHJ, or to a much lesser extent Dolby Surround/PL/PLII)->Surround.

Standard Stereo, as it is predominantly currently practiced, DOES NOT CONTAIN the necessary information to describe a full (or near-full) 3-dimensional space. It uses crude approximations of IAD in its panning modules and barely even uses ITD except in special effects, and forget about HRTFs. This weakness is aggravated by the monolithic procedure of using simple stereo speakers to reproduce the encoded stereo signal.

Scott

[pandy]

I think from formal perspective this will be more like interpreting information in a different way...

Only theoretically, or going something esoteric like Binaural (or Ambisonic UHJ, or to a much lesser extent Dolby Surround/PL/PLII)->Surround.

Standard Stereo, as it is predominantly currently practiced, DOES NOT CONTAIN the necessary information to describe a full (or near-full) 3-dimensional space. It uses crude approximations of IAD in its panning modules and barely even uses ITD except in special effects, and forget about HRTFs. This weakness is aggravated by the monolithic procedure of using simple stereo speakers to reproduce the encoded stereo signal.

Scott

This depends.
For stereo recordings all is an audio guy and his mixer (i think about multi microphone/track recording - stereo image is created on mixer console), in case multichannel (i.e. surround which is recorded in simialr way as earlier stereo example but goal is to produce multichannel recording) sound there is downmixing of surround to 2 channel (i doubt that any reasonable movie company will create completely independent stereo signal mixing - usually they use well known downmixing matrix).
As such before stereo it was real multichannel and it was usually downmixed to stereo.

I'm not arguing how accurately stereo can be processed to recover/recreate information before downmixing - this will be like coloring grayscale movie or restoration mono recordings from beginning of the previous century to stereo but for sure there are some techniques (audio decomposition algorithms) that may provide particular level of objectivity in audio restoration so not everything is only subjective and this was my general idea.

[El Heggunte]

Okay, to whom this may interest:

http://forum.doom9.org/showthread.php?t=105684

NOTICE, I haven't changed my mind — but if anyone feels like doing some experiments, why not

[hello_hello]

I must have been fairly bored, because I followed El Heggunte's link and eventually converted a stereo track to 5.1ch, despite knowing surround sound sucks and blows at the same time. I already have foobar2000 and the VST Adaptor ready to go though, so it only took a few minutes, although there's probably no need to re-encode stereo music files as 5.1ch if you use a PC as a media player anyway, because it can be done on playback.
Foobar2000 can use the same DSPs for either converting or inserting in it's playback chain, and there's obviously no issue up-converting in real time.

Ironically.... I guess.... I don't have a 5.1ch sound system, due to surround sound sucking and blowing simultaneously.... so I can't listen to the result in surround myself. Someone else will have to tell me how the attached samples sound.

Following the link in this post I installed the V.I. Suite VST plugin. The installer doesn't seem to do much other than put some files in whatever location you specify, and then it's just a matter of telling foobar2000 where to find VI.dll.
I've attached the stereo audio and three 5.1ch "up-conversion" samples. The names of the 5.1ch files are taken from the V.I. Suite presets I used when converting. They're AAC. My internet connection is dog slow and for the purpose of the exercise, AAC should do.

nixiejames,
Can aimp convert to 5.1ch on playback too or does it need to do it while re-encoding?