I wrote to the list earlier about optimizations of the tremor. Specially replacing the IMDCT with a N/4 FFT. The report is available here: http://www.sandvall.nu/thesis.pdf Short summary: Optimization of the Tremor code under 50kB for a "split" decoder version. ~44 MIPS. Huffman highly unoptimized. IMDCT ~ 8 MIPS. Quick overview of the Ogg/Vorbis format and a psycho acoustic introduction. I've send code to the list about the FFT but that seems to have disappeared somehow... Maybe the attachments got lost somewhere. Most of the code is free, all of the stuff in the report. The parts developed in cooperation with Ericsson mobile platforms is not available. Give me feedback if any parts of the code is of interest. If there is any questions please send them but check in the report first if the answer is there. Regards / Johannes Sandvall, Erik Montnemery --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
On Thu, 11 Mar 2004, Johannes Sandvall wrote:> The report is available here: http://www.sandvall.nu/thesis.pdfThanks for posting this ! Great Stuff ! BTW: AFAIK, AAC isn't used for DVDs. <p>Ghis! Sebastian -- PGP-Key-ID (long): 572B1778A4CA0707 --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
Hi Johannes, do you mind making the pre-sort and FFT source code available somehow? I suppose it would give a performance boost to my Java based Vorbis decoder as well. Tor> I've send code to the list about the FFT but that seems to have > disappeared somehow... Maybe the attachments got lost somewhere.<p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.