similar to: MDCT document

In mdct.c there's some functions including some-point butterfly. In 32-point and 16-point there are calling of smaller-point function everytime twice on each half of data. When I looked on it I found that's just linear algebra. So it can be rewritten to matrix multiplication. Some one can say: there's optimization on in register working. But imagine there's one calling 32-point,

hello, i'm reading the doc at http://xiph.org/ogg/vorbis/doc/Vorbis_I_spec.html and the link to the paper http://www.iocon.com/resource/docs/ps/eusipco_corrected.ps doesn't work. Could anyone correct the link and/or mirror this paper ? Thanks, YG --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list,

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi! I want to encode wav file into fixed window length vorbis file. I don't know if "window" is good name for that, but i mean MDCT buffer size. This buffer is passed to mdct_backward() as "in" and it's size is determined by "init->n" variable which is also passed to this function. So, when I say "window

Hello, In the "Documentos" section SanJaaC Electronics' website you can now find a zipped version of the paper "The use of multirate filter banks for coding of high quality digital audio" by T. Sporer, K. Brandenburg and B. Edler. I hope this helps to relieve the shortcoming with the -404 error message when trying to access it form other sites. Please let me know if I am

Sorry for starting another topic, this is actually a reply to Segher's post on Sun Oct 22 on the 'mdct question' topic. I wasn't subscribed properly and so I didn't get email confirmation and thus can't add to that thread. So Segher, if the equation is indeed what you say it is, then replacing mdct_backward with this version should work, but it doesn't. Am I applying

Hi, I'm currently working on a paper describing Ogg Vorbis. It is not finished yet. Mostly the decoder is being described. If you have any comments, please send them to me. See: http://www.turbocat.net/~hselasky/math/vorbis/files/ Then I have a question about the function "bark_noise_hybridmp()" which is used in the encoder. Can someone describe what the function does in

Hello everyone, the code is slowly getting a little bit messy, but at least I've managed to tweak a lot of performance out of my Vorbis player for Flash. I did several improvements to the Huffman decoder by eliminating function calls and managed after a while to create an AS/haXe hybrid player. The haXe compiler definately produces much more efficient bytecode (at least in some

Hello !! While reading I am facing lot of problems . Doing reserve enginnering without any document is really putting in trouble . ( that is not the case in ac3 , mp3 ) . The problems are ----> 1. How physcoacoustic model is generated . I was reading noise masking . I have understood that FFT of 2048 samples is used for finding tone masking . And MDCT of same samples is used for

Hi All, Currently I am investigating how interesting OGG is for me. The most important requirements are: - Decoding on embedded hardware, ARM7 or ARM9. - Mixing multiple audio streams/files on embedded hardware First of all how difficult is it to decode OGG on an ARM7/9 processor? I read that OGG decoding needs floating point support? Secondly I would like to know how many MIPS are needed to

Hi !! <p> I am just now reading Vorbis I specifications . I ahve some quries in that regading overlap add and sqaure polar mapping . I am writting this mail with the hope that ,some one will resolve my quries. <p> 1. After IMDCT , to remove the aliasing , we do overlap and add . For that the window should have following properties -------------> hk =

Hello, Normally, in addition to such qdisc scheduler mechanisms as FIFO, PQ, WRR, WFQ, are there any more? Then, there is a confusion on scheduler in Linux enviroment: Assume there is a qdisc, such as RED as a leaf qdisc in a router, we know, if there is packet which want to enqueue the packet, the Function red_enqueue is called, but when the packet leave the queue(when the Function red_dequeue

Hi I've got serious problem with my Vorbis-Decoder. The error seems to happen in the inverse Mdct. Before the imdct the values seems to be correct (compared with those of jOrbis (www.jcraft.com/jorbis/)). But after the transformation the values shows a strange behaviour. In [0, blocksize/2] the values are correct, but in [blocksize/2, blocksize] the values are wrong. The difference in

Dear Experts, Can anybody please direct me to proper MDCT theory reference which will help me understand the code better? I'm trying to optimize MDCT for a embedded platform. So need good understanding about theory behind & implementation. Thanks in advance for your time. Warm Regards, Mahantesh -------------- next part -------------- An HTML attachment was scrubbed... URL:

Hi vorbis-dev! I'm working with Pattara in the oggonachip project, and wondering about the implementation of mdct.c as hardware. According your recomendations about using the floating point version, I would say, we have to implement the integerized version of mdct as a core, and use the fpu only to round the input values. By doing that, you think the result would be still acceptable? How

Hi, Can someone tell me which MDCT and invMDCT equation uses? I implemented the invMDCT one given in eusipco.corrected.ps file (handed out by Monty way back) and it produces different time domain samples. I tried both the FFT method and the slow way directly from the equation and couldn't reproduce the results from the original code. This leads me to believe that the forward MDCT used in

Dear all In the paper section describes how CELT and SILK had implemented a look/up head delay of (2.5ms), (5ms) respectively , could you explain me> 1) those values are fixed. 1) how you guarantee those values independent of the architecture's performance. Thanks so much On Tue, Apr 18, 2017 at 10:05 AM, Diego Alejandro Parra Guzman < daparrag at correo.udistrital.edu.co>

Hi, I have a doubt regarding MDCT window size for OggVorbis decoder. Can the MDCT window size vary from 64 samples to 8192 samples? Specification says that "legal frame sizes are powers of two from 64 to 8192 samples" . Is this same as MDCT window size? Please help me out.. Regards, shikha <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage:

Hi, as we are trying to implement MDCT in hardware, we are caring now about the "n" (size of input and output vectors to and from MDCT). As I have looked in the code, this "n" is chosen from the Ogg/Vorbis stream data in info.c:_vorbis_unpack_info() which means this "n" can vary aribitrarily (as the power of 2) depending only on the value got from song data? or is

Dear all I'm working on the implementation of the MDCT for the processor ARM-Cortex-M4 I'm trying to replicate the behavior of the MDCT for several overlapped values however I realized that current implementation of the MDCT is very close to the theory only in case in which we have and overlap exactly equal to N/2 where N is the size of the input vector as is shown in the examples for

I did composition of butterfly8 and butterfly16 and I found, that these functions are well decomposed - decomposition doesn't lower computional speed. On the other hand the same can be done with butterfly8 - decomposition to butterfly4 (further decomposition is not possible) but there's no reason to do this. I think little improvement can be done by inlining them. Compiler and processor