48khz->44khz-48khz

[stanleycup]

I was using DVD2SVCD to encode a movie and I downsampled the audio
to 44 khz for SVCD compliance.

How much audio quality would I lose if I take the 44khz audio portion and converted (upsampled) it back to 48khz?

Would it be that noticeable?

Thanks for the help

[Antimon]

Any information you lost *which really isn't much* is already gone, so upsampling will not get it back so i dont see why you are concerned about upsampling back to 48...it's just going to give you less bits for the audio you do still have intact.

going to 44 all that relaly happenes is that you lose the ability to playback audio between 22 khz and 24 khz, the human ear can't hear above 22 khz anyway.

You also get a very slight loss of resolution in sample acuracy but i doubt it's noticable on most speakers to most ears.

[stanleycup]

I had downsampled my DVD audio encoded to 44 khz to be compliant with SVCD but I found out that most DVD players will play SVCD at 48khz.

I want to upsample back up to 48khz so that I can take the SVCDs I have created before and burn it on a DVD-R which requires the audio to be at 48khz for DVD compliance.

BTW, do you know if VCDs can be played at 48khz on DVD players?

[DSPguru]

Originally posted by stanleycup
I want to upsample back up to 48khz so that I can take the SVCDs I have created before and burn it on a DVD-R which requires the audio to be at 48khz for DVD compliance.which format would you be using ? mp2 ? mp3 ? why not using the original ac3 ?

BTW, do you know if VCDs can be played at 48khz on DVD players? most dvd players playback svcds with 48khz mp2 without any problem. downsampling to 44.1 just takes more time, and usually isn't needed.

[stanleycup]

Most of the DVDs I have converted to SVCD, I don't have the AC3 file anymore. I would be using the mp2 (48khz) file for the DVD-R.

I thought I could use the mp2 file for the DVD-R or do I need the AC3 file for DVD-R creation. I read some people saying I need the AC3 file and other people saying I only need the mp2 file. What is the final answer to this?

I now know that DVD players play SVCDs at 48 khz but my question actually was if DVD players also play VCD at 48khz since by default the VCD standard says it needs 44khz. I would guess that a VCD at 48 khz should be ok.

[DSPguru]

for the best replies about this, i suggest that you ask over at the vcd authoring forum and dvd/minidvd authoring forum.

keep in mind that each player has it's own capabilities. mine, for instance, is capable of playbacking vcds with mp3 soundtrack.

[Antimon]

Yes it's not all abotu compliance, and is really dependant on the player

it sounds liek you have a fiarly new one since it suports dvd-r

Basically the drive and hardware is the same nomatter what it's reading, so if it can read dvd's at 48 it should be able to read vcd's at that rate.

mpeg2 streams can contain ac3, mp3, oor uncompressed pcm audio tracks in any combination, are you generatign an mpeg2 ...or are you just going for higher bitrates and more files, but mor eor less stickign to svcd data structure?