similar to: MDCT implementation and his overlapped relationship

Dear all, Sorry for this simple and maybe stupid question, I'm working in the implementation of opus for ARMv7e microcontroller using a library CMSIS/DSP used to calculate the CFFT and MDCT based on the DCT-IV. my question is: In the implementation of Celt you have used a fixed length CFFT equal to 1920, I want to know if there is some issues which can appear if a change that configuration

Dear all, Currently I'm working in and optimization of opus for an arm-architecture *"armv7e-m"* I've involved in the general opus documentation as well in the architecture, however opus Is so big and difficult to discover specific optimization points, I want to know if you could give me a general view about of the principal points that I have to consider in order to optimize

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>

Dear all. According with my question. CELT CFFT size configuration I'm not completely sure about how the kiss_fft works for sizes which are not power of two, as occur in the case of celt which calculate the mdct using a fft sizes of 480, 240, 120, and 60, I guess that internally the input data is padded with zeros in order to compute efficiently the mdct using the Cooley and Tukey

Hi Diego, Really, the only way to know what to optimize is to run a profiler. Optimizing without profiling is a waste of time and is often harmful. Cheers, Jean-Marc On 18/04/17 04:12 AM, Diego Alejandro Parra Guzman wrote: > Dear all, > > Currently I'm working in and optimization of opus for an > arm-architecture *"armv7e-m"* I've involved in the general >

Dear all: I want to formulate couple of questions about SILK codec: 1. I've seen the documentation to the SILK codec that is part of the OPUS exactly the paper with title "The opus codec voice coding with opus, and the "RFC 6716 specification of opus" . Well, I detected that in both is defined a High-Pass filter as part of SILK; however in the paper you put the following

Hi all: I'm successfully run OPUS in cortexM4 arm architectures using a cross compiler gcc-arm-none-eabi . I recommend to uses the following precompile flags before to compile you code: arm-none-eabi-gcc -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-dl16 -std=c99 -fasm -DARM_MATH_CM4 -DOPUS_ARM_INLINE_ASM -DOPUS_ARM_ASM .... and in your configuration file of OPUS you could use the

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,

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, 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

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, 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

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

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 trying to determine how the frequency data that is passed to the MDCT, and output time domain data obtained from the MDCT, is changed when setting #define MDCT_INTEGERIZED For instance, the trig array, for a size 256 window begins 1.000000 0.000000 0.998795 -0.049068 0.995185 -0.098017 if INTEGERIZED is set, then it begins 16384 0 16364 -803 16305 -1605 which is simply a left shift

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:

The Vorbis audio format, uses something called the Modified Discrete Cosine Transform (MDCT). I was interested in how this worked, but did not know where to start. Is this the name of a particular algorithm, or does it just mean something like a cosine transform, but not quite right? So I asked the Vorbis mailing list. Nobody answered. It was not a high priority, so I did other things for

Hi vorbis-dev, I'm investigating the mdct* function in libvorbis and writing a small client program to test it. I found that I have to set ARRAYSIZE when mdct_init(lookup, ARRAYSIZE) to minimum value of 62 otherwise it will segfault with mdct_backward. Is there any lower limit or it is more likely that my code has bug? Thank you very much, Pattara -- Please avoid sending me Word or

In vorbis/lib/mdct.h the following are defined: for integer: #define TRIGBITS 14 #define cPI3_8 6270 #define cPI2_8 11585 #define cPI1_8 15137 #define FLOAT_CONV(x) ((int)((x)*(1<<TRIGBITS)+.5)) for floats: #define cPI3_8 .38268343236508977175F #define cPI2_8 .70710678118654752441F #define cPI1_8 .92387953251128675613F #define FLOAT_CONV(x) = x Could someone explain where these values

Hello, I have a small Puppet 2.7 module to configure Sonatype Nexus Professional. The module takes, among other things, a baseurl in the form of "http://example.com/path" and I''d like it to extract the "/path" from that variable into a separate variable IF an optional "path" variable haven''t been supplied. Here is an extract: class