Hello,
I am currently working on HE AAC v2 for DRM application. I am using a source code from ISO and i see that the parametric stereo feature is not compatible for a 960 transform length as ISO code supports only for 1024 transform length. However they state that it is compatible for 960 length but i see its only for the AAc core decoder.
I am looking for some theory/document which would help me for modifying the parametric stereo tool for 960 transform. I request if any one has come across similar issue or maybe some guidance. It would be very helpful.
Thank you.
I know that DAB+ digital radio uses HE-AACv2 with PS and also has a transform length of 960. So, it is indeed possible but it appears to be a limitation of the reference implementation (http://www.opendigitalradio.org/index.php/Example_of_the_creation_of_a_DAB%2B_transmission), not a technical impossibility.
Actually, on further research on the site behind the link above (Opendigitalradio.org (http://www.opendigitalradio.org)) it turns out they have "A free/open DAB+ encoder". In the changelog (https://github.com/piratfm/fdk-aac-dabplus) for the project they mention "AAC960 works now. All modes: LC/SBR/PS. Only for DAB+, not DRM."
That looks like it could be a good starting point for you.
Hello Maurits,
I got the code and have started looking into it. Thanks a lot. I got some hint ;-)
Hello Maurits,
I got the code and have started looking into it. Thanks a lot. I got some hint ;-)
That's good to hear. If you do manage to solve it and are legally able to share the code, it would be nice if you could share your findings/code with the Opendigitalradio project. I'm sure they would like to include AAC960 for DRM+ too...