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State of the art lossy codecs and surround formats

Reply #25
It can lead to same situation as for JPEG image format.  All its patents have been expired and there were a number of a newer image compression formats (JPEG2000, JPEG XR, WebP (intra VP8) and lately HEVC-based BPG). But none of them come any closer to JPEG's status of leading/most popular image format.

The same story will probably happen with mp3. We are just 2 years away from expiring it's last patents in April 2017. With zillions mp3 supporting devices around the world it will seriously reduce importance of free lossy audio codecs like ogg or opus, at least at high bitrates 128k+.


IIUC, the last mp3 decoder patent in the USA expires in 2 weeks.



State of the art lossy codecs and surround formats

Reply #28
Yes, it's more complete.
Though both sources indicate that the last MP3 patent will expire 16/04/2017.  Exactly 2 years from today.

State of the art lossy codecs and surround formats

Reply #29
The extra additions for the "USAC-plus" core codec in MPEG-H 3D-Audio (MHA? 3DA?) seem like they'd be really useful for normal, stereo mid-bitrate situations. At least one of the tools, the combined parametric + residual stereo mixer, simply reads like someone forgot to include it in the original USAC spec. 

Wait a minute. A combination of parametric + residual isn't part of USAC? According to this presenetation it is. http://www.filedropper.com/aes132mpegxhe-a...aunhoffer132aes.

Yes, it could be useful for stereo content at 48 kbps and maybe somewhat  up to 64 kbps

State of the art lossy codecs and surround formats

Reply #30
nice lists thanks for information

State of the art lossy codecs and surround formats

Reply #31
The extra additions for the "USAC-plus" core codec in MPEG-H 3D-Audio (MHA? 3DA?) seem like they'd be really useful for normal, stereo mid-bitrate situations. At least one of the tools, the combined parametric + residual stereo mixer, simply reads like someone forgot to include it in the original USAC spec. 

Wait a minute. A combination of parametric + residual isn't part of USAC? According to this presenetation it is. http://www.filedropper.com/aes132mpegxhe-a...aunhoffer132aes.



From what I understand, USAC switches between parametric and residual per subband in an either/or fashion. MPEG-H adds (always-on) implicit weighing between parametric and residual information based on the difference between their energy for that band.

Quote
Yes, it could be useful for stereo content at 48 kbps and maybe somewhat  up to 64 kbps


In terms of usefulness at higher bitrates, I was thinking of the addition of transform splitting and generalized gap filling tools. The former allows 512 block lengths, as opposed to 128 or 1024, which seems applicable to most bit ranges. It's a bit harder to characterize what they call IGF (intelligent gap filling), but it reads like a generalization of SBR-esque coding to the MDCT domain with more precise/localized frequency replacement. The IGF tools is self-limiting, unlike SBR, in that it doesn't do anything at high bitrates when there are no spectral gaps to replace. That last detail is what I thought HE-AAC needed from the very beginning.

One last this-would-have-been-nice-to-have-since-forever thing is the built-in ability to hide priming samples in pre-roll frames that the decoder will simply discard once decoded.

State of the art lossy codecs and surround formats

Reply #32
If I understand it correctly SBR/eSBR will be replaced by IGF in 3DA.  Description of IGF

IGF should be considerably better than SBR/eSBR.

If this is so then it's great! Because when I've heard USAC with its eSBR for the first time my first thought was "this is still SBR-ish".  USAC's eSBR still uses QMF transform just as HE-AAC's SBR which still causes both frequency and temporal/transients distortions. Though it's still a bit better: USAC (with eSBR) at 64 kbps is on par with HE-AAC(with SBR) at 70-75 kbps.


So it seems like 3DA can have substantial improvements (IGF, weighing between parametric tools and residual coding for stereo, etc.)  on interesting range of bitrates for multichannel as well as stereo material.

I hope only for one thing. That there will be at least one single high quality encoder available any time soon. Yes, I have repeated many times and I will repeat it again that there is still no available (for simple mortals) MPEG Surround nor USAC encoder. Or is it just developers who have stopped to care?


 
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