5.1 to 2 channel downmix

2005-01-01 04:17:27

some question regarding 5.1 to 2 channel (azidts)

is it correct in 5.1->2 downmixing, my instinct tells me it is incorrect
I've uploaded 2 sound capture, one from windvd
and the other one is produced by azidts

1st gunshot is OK

Listen carefully to the 2nd gun shot in each track
after the gun shooting sound, the water splashing is downmixed
quite different with windvd and azidts

WinDVD's water splashing sound is from the left channel only

while azidts is in the right channel!!

which is right and which is wrong?, my instinct tells me windvd is right, the water splashing hapens in the left half screen (bad describtion, hope u understand what i wanted to express)

Samples

5.1 to 2 channel downmix

Reply #1 – 2005-01-01 10:25:23

Did you use azidts directly or through besweet? Try http://www.doom9.org/index.html?/oagmachine.htm . It allows you to experiment with different downmixing methods (stereo, pro logic, pro logic2).

5.1 to 2 channel downmix

Reply #2 – 2005-01-01 14:45:02

I use besweet GUI

these are the checked setings

LFE to LR -3db
Surround downmix 0db
normalize
hybridgain, that's all, other checkbox are not checked

5.1 to 2 channel downmix

Reply #3 – 2005-01-01 17:30:27

There is the downmix method on some property page. Find it and try if it helps you.

5.1 to 2 channel downmix

Reply #4 – 2005-01-02 06:09:16

I figured out,
if dolby compatible downmix is used, the splashing sound will come out of the right channel

if stereo is selected, it will be from the left!!

so dolby or stereo? I thought dolby is more accurate than just stereo?

2.      besides, Foobar also has 5.1 ->2 ch, and the DTS decoding speed is much faster than besweet
Besweet can encode DTS at  realtime, which is very slow
is foobar2000 downmix dolby compatible or it's just simple stereo?


3.      or maybe i can just use HE-AAC at 96kbps? for 5.1? then I won't face all those downmixing headache
is He-AAC supported by matroska container! I don't want to end up playing back HE-AAC without SBR (it sounds awful)

5.1 to 2 channel downmix

Reply #5 – 2005-01-02 09:40:09

Dolby modes allow your home theater rig to extract extra channels from your two channel source.
96 kbps he aac isn't enough for 5.1 sound. I'd use at least 160 or 192 kbps. Matroska supports even he aac + ps.

5.1 to 2 channel downmix

Reply #6 – 2005-01-02 14:15:47

I've tried to encode short files, and Internet (~128kbps) has echo which is too long and abvious enough, very annoying!
streaming (~167kbps), iss acceptable!

annyway what's PS

And is it recommended to check the so called "PNS"?

5.1 to 2 channel downmix

Reply #7 – 2005-01-02 14:35:00

Don't know about pns but ps (parametric stereo) isn't even available yet.

5.1 to 2 channel downmix

Reply #8 – 2005-01-03 12:31:10

PS, is it something like SBR, SBR is for frequency and PS is for channels?

i know mp3pro has this too, it save files in mone and playback in stereo?

about PNS thing, I think i need to start a new topic in aac section, i van & menno would surely know the answer