search for: psychoacoustic

Good Morning; Iam asking whether any one have knowledge about is it possiple to incorporate a psycoacoustic model?(specifically?I mean ?MPEG-1 psychoacoustic model 1) into the CELT codec(any version even older versions of the coder,?no matter) Iam using version 0.3.2. Kind Regards; Osama. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.xiph.org/pipermail/opus/attachments/20110425/24ae7c0d/attachment-0002....

Hello, Tell me please where I can find detailed description of the Vorbis psychoacoustic model? <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-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscr...

Hi, I need a psychoacoustics model for some experiments and would like to use the one included in vorbis. Is there any documentation about how to use it? Looks like the relevent code is in psy.c, but I can't go further. Also I would like to know whether I can be of any help in vorbis. I have some knowledge in speech codi...

Hello everyone, I need to know which kind of psychoacoustic model is used in vorbis to encode signal. Thanks for answers __________________________________ Do you Yahoo!? New Yahoo! Photos - easier uploading and sharing. http://photos.yahoo.com/ --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To u...

Hello, I'd like to know there is any place (web, document...) where I can see which the vorbis' psychoacoustic model is, at least for the reference encoder (how it works, algorithms, filter banks, scalefactors, etc., or if it doesn't use any of this things at all...), or if the only way of looking at it is within the psy.c. I've been looking for it in the Vorbis' site and in the web but haven...

Hello! I don`t know C or C++, but I want to prepare some psychocuostic experiments in the MatLab. Shuold you tell me where I can find detailed description of the Vorbis psychoacoustic model? <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. Unsu...

...mental of signal > processing concepts. Go get an undergraduate level book on signal > processing (eg, _Understanding Signal Processing_ or _Signals and Systems_) > and read it. This is all covered first month. On this subject, could you (all) recommend some good vorbis-relevant dsp and psychoacoustics texts? There seem to be a lot out there to choose from. (For DSP, I own _A Digital Signal Processing Primer_ by Steiglitz, which seems like a good introduction and has some practical commentary. I also have _Digital Signal Processing: A Practical Approach_ by Ifeachor and Jervis. This is not as...

...overlapping windows with sizes between 64 and 8192 Samples (powers of two) - short blocks and one long blocks are used (short blocks must be smaller or equal to long blocks), can be set to any allowed size - selected window size depends on bitrate MDCT - transforms audio data to frequency domain PSYCHOACOUSTIC MODEL - Vorbis uses its own psychoacoustic model - FFT for tonal analys and MDCT for noise analysis Floor - a psychoacoustic floor is created from the data, given from the psychacoustic model - the floor is a spectral envelope and represents a low resolution model of the audio spectrum - floor typ...

We've implemented a vorbis decoder based on Tremor and as part of the documentation we're also writing about psycho acoustic models and encoding. We're quite up to date with the decoding process and psycho acoustics in general but unfortunately not on the psycho acoustic encoding used in Vorbis. We have a few questions that would we would be very thankful to have answer to: Which

...niverstiy of Delaware, and will be soon starting some research on the effects of lossy audio compression on speech sounds. I will be preforming test with both mp3 and vorbis. First of all, if I use the '--ogg' switch to lame, does lame use GPSYCHO to encode the wave, or some other psychoacoustic model (perhaps one designed for the vorbis algorith)? Along these lines, I'm unable to get lame-3.89 and libvorbis rc2 to play nicely together. The lame build breaks when compiling ogg support (this is probably a known bug, so I'm not posting relevant details. If I'm wrong about it b...

...overlapping windows with sizes between 64 and 8192 Samples (powers of two) - short blocks and one long blocks are used (short blocks must be smaller or equal to long blocks), can be set to any allowed size - selected window size depends on bitrate MDCT - transforms audio data to frequency domain PSYCHOACOUSTIC MODEL - Vorbis uses its own psychoacoustic model - FFT for tonal analys and MDCT for noise analysis Floor - a psychoacoustic floor is created from the data, given from the psychacoustic model - the floor is a spectral envelope and represents a low resolution model of the audio spectrum - floor typ...

...bshine.so.1.0.0 to /system/lib/libshine.so.1 and bin/shineenc to /system/bin. On my low-end HTC, however, encoding is not real-time, which is a bit disappointing: $ shineenc bla.wav bla.mp3 shineenc (Liquidsoap version) WAV PCM DATA, stereo 44100Hz 16bit, Length: 0: 0:18 MPEG-I layer III, stereo Psychoacoustic Model: Shine Bitrate=128 kbps De-emphasis: none Original Encoding "bla.wav" to "bla.mp3" Finished in 0: 0:20 If anyone else feels like testing on another ARM android phone, I'll be interested to know if the encoder may be used to encode to mp3 in real time... Romain...

...ates (1:4 compression ratio), Vorbis or LAME, I would like to know how to compare the original audio and the decoded audio? With LAME, a simple sample-by-sample comparison failed badly (the error was as high as 7 bits). With ratio 1:4 I aim at archival quality and thus the overall error counts, not psychoacoustics. Best Regards, Juhana --- >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 nee...

Hi all, I want to make a static database containing hundreds of thousands of very short audio files, each having not more than 100 milliseconds. These are made by splitting larger audio files into tiny pieces. I encode all the little files separately, but do not store 3 vorbis header packets, which are the same for all the files. I do not use ogg stream, only store plain vorbis packets.

Hi, In paper" A High-Quality Speech and Audio Codec With Less Than 10 ms Delay", you are mention that: There are still several ways to improve CELT, such as by incorporating better psychoacoustic masking in the dynamic bit allocation. This is a difficult problem both because there are few bits available for coding the allocation and because the analysis window is short. it is possible to implement that and what are the correct approaches to do that. Best Regards, Nidaa A. Abbas

Hello vorbis developer! I'm not very experienced in informatics, cause i'm only an audio engineer and sorry for my broken english but i have an idea... After the filterbank the maximum aplitude in each band decides about the nessesary bits, then the psychoacoustic model decides how much of the signal can be truncated without hearable noise. What do you think about quantising the remaining bits nonlinear with a logarithmic scale? This would share 25%. Nonlinear quantisation is used for instance in a-law or for the longplay-mode of DAT-recorders. The disadv...

...oderation queue, so I subscribed and re-sent it.] I'm doing some work on audio fingerprinting for a school project (more precisely, my master's thesis. I got a hint on #vorbis that I might want to look into the internal floor representations in libvorbisenc to get out audio data after the psychoacoustic masking, but I'm having problems actually getting out the right data. Basically, I'm looking in mapping0.c, dumping out the debugging information that's already there. One of the most promising places seemed to be just before floor1_fit, but it seems a bit odd: http://home.samfundet...

Hi, I'm a newbie to audio compression. And I have several question about ogg. 1. How many bits a vorbis sample take ? does the sample size 16 bits ? like the mp3 ? CMIIW 2. How do a decoder recognize how many sample it takes in a second ? does it related with the code books ? 4. Does vorbis use VBR ? 3. What is function of the Windows ? and what is the output of the windows ? Thanks

...at, like it should be, from 0-20000 Hz. There are two 6dB dropout imperfections in the high end; I need to look at this flaw (you never know... maybe the r3mix guy was right after all and there *is* a masking bug ;-) Response is not perfectly flat (there's a half dB ripple or so) because the psychoacoustics say that's fine and the psychoacoustics are correct. Unlike most mp3 encoders, Vorbis totally trusts its psychoacoustics and because it's natively VBR, it won't try to use up 'extra' bits resulting in .000025 dB resolution on a very simple sample like this. The logsweep encod...

Hi, Does anyone have an idea about the possibility to apply psychoacoustic models as the ones in mp3 or AAC to a CELP coder? Thanks! /Pontus <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 'speex-dev-request@xiph.org' containing only the word ...