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Topic: Spectral Band Replication for Ogg Vorbis (Read 10644 times) previous topic - next topic
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Spectral Band Replication for Ogg Vorbis

Hi,
Spectral Band Replication is a bandwidth extension which greatly improves efficiency in AAC today, I was wondering whether it is possible to implement an opensource SBR for Ogg Vorbis.
I recall ones there was an alternative to the Coding Technologies one called "Vplus" or something like that, used along with MP3. I think I has been discontinued why?
Could be possible to create a similar opensource version?

Regards
Enrico

Spectral Band Replication for Ogg Vorbis

Reply #2 –
Thank you. I will check these links

Spectral Band Replication for Ogg Vorbis

Reply #3 –
Quote
I recall ones there was an alternative to the Coding Technologies one called "Vplus" or something like that, used along with MP3. I think I has been discontinued why?
It's not 'discontinued'.. it's just that NOBODY has tried doing anything to improve it (maybe I will.. in like 20 years or so  )
Vorbis-q0-lowpass99
lame3.93.1-q5-V9-k-nspsytune

Spectral Band Replication for Ogg Vorbis

Reply #4 –
Quote
Quote
I recall ones there was an alternative to the Coding Technologies one called "Vplus" or something like that, used along with MP3. I think I has been discontinued why?
It's not 'discontinued'.. it's just that NOBODY has tried doing anything to improve it (maybe I will.. in like 20 years or so  )
[a href="index.php?act=findpost&pid=378819"][{POST_SNAPBACK}][/a]



Good news.

I do understand from the plusV website that PlusV unlike SBR from Coding Technologies plusV doesn't replicate lower frequencies. The higher frequencies are not generated from the lower spectrum at all, the high frequencies are only sub-sampled to detemine the amount of noise in each subband. On the reconstruction phase, a pseudo-noise is generated according to the auxiliary data. Correct?

Spectral Band Replication for Ogg Vorbis

Reply #7 –
Quote
Hi,
Spectral Band Replication is a bandwidth extension which greatly improves efficiency in AAC today, I was wondering whether it is possible to implement an opensource SBR for Ogg Vorbis.
I recall ones there was an alternative to the Coding Technologies one called "Vplus" or something like that, used along with MP3. I think I has been discontinued why?
Could be possible to create a similar opensource version?


Vorbis has it's own special type of "PlusV", it's called Noise Normalization. The algorithm that's in the source code is a temporary one that can be improved greatly. It's fairly straight forward too and is very pleasent sounding, more so than SBR IMO. 
budding I.T professional

Spectral Band Replication for Ogg Vorbis

Reply #8 –
Quote
Vorbis has it's own special type of "PlusV", it's called Noise Normalization.

They are totally different things.

Spectral Band Replication for Ogg Vorbis

Reply #9 –
Quote
They are totally different things.


Yes, but they are quite similiar in what results they are trying to achieve. I think the problem is that a lot of folks really don't understand the Vorbis source code that well, it's quite difficult to dive into the low-level libraries and routines, but it can't be exactly the same too.
budding I.T professional

Spectral Band Replication for Ogg Vorbis

Reply #10 –
Quote from: HotshotGG on
Quote
They are totally different things.


Yes, but they are quite similiar in what results they are trying to achieve.


No, no, no, not at all. As Gabriel already said, they are entirely different things. See the analysis by synthesis discussion here; it seems there isn't even agreement about whether the basic principles underlying it's operation are correct.

Spectral Band Replication for Ogg Vorbis

Reply #12 –
Quote
No, no, no, not at all. As Gabriel already said, they are entirely different things. See the analysis by synthesis discussion here; it seems there isn't even agreement about whether the basic principles underlying it's operation are correct.


Where is this discussion again there are so many links being thrown around?. The algorithm seems fairly straightforward  to me, I am still trying to understand exactly what it does, but the basic jist of it is that is redistributes the noise energy in specific frequency band that has the lowest SNR. It does this somehow with the residue. I know that it uses an apsort to do so.  That's the way I have come to understand and wrote about it in the wiki.
budding I.T professional

Spectral Band Replication for Ogg Vorbis

Reply #13 –
Noise normalisation is there to preserve energy in quantized subbands.
PlusV is a tool to parametrically store and reconstruct higher part of the spectrum.