search for: preecho

...up!) is maintaining a vorbis audio quality test page: http://hem.passagen.se/ingets1/vorbis.htm He's doing us the great service of hunting down samples that break Vorbis (so we don't have to :-) In any case, it turns out that the trumpets in the dr4 sample are reliably mistriggering the preecho detector (which implies either a large bug in the detector, or general borkkenness which must be fixed). The artifacts in the sample are due entirely to Vorbis trying to encode the trumpets entirely in short blocks (which will suck for strongly periodic/harmonic waveforms, as produced by brass ins...

Hi! Dear all I compressed an audiu(wave) with libvorbis1.1.1 and found that the pre-echo was longer than the one which was compressed with MP3 at the same bitrate(128kbps),I am now confused aboout the pre-echo preventing scheme. Can you tell me what method does Ogg Vorbis adopt besides the auto windowsize switch? Looking forward to your letter! Thank you! ??????? Lisa (^_^)

hi; i'm a lurker & trying to make sense of the discussion... is there a glossary of terms available somewhere? mdct, wavelets, 4th dimensions & preechoes remind me of my time in the twilight zone;) thanks peter --- >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'...

Hi, I'd like to contribute to Vorbis and I think this may be of some interest for low bitrate coding. I have been experimenting with low bit-rate coding for the high-band (11 kHz to 22 kHz) and, though I haven't yet started quantizing my coefficients (a gain and an LPC filter), I expect to be able to approximate the whole 11-22 kHz band with around 1000 bits/s per channel (maybe even 500

...current Monty branch and I've found a case where it performs poorly. I havn't had a chance to verify the mainline (network at home isn't working; System with good headphones isn't on net, and I've only sneakernetted the branch).. The gspi35_1 sounds like it's suffering from preecho. I changed the preecho threshold to make more shortblocks, but it sounds worse. I had believed that short blocks were fixed in hte branch.. --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/

Hello, I am author of a Morse code training software written in Perl at http://starling.ws/morse Currently I output to *.wav and, if on Unix, convert to *.ogg. And that's okay for a trainer. But I have desire to upgrade the project to a real-time communication tool...or at least a Morse code audio mail routine. And I should like to avoid *.wav. I'd like some means of writing a pure

Hi. Since I'm new to this mailing list, I don't know whether this was discussed in this mailing list, or if it is already fixed. Anyway, the problem is that all audio encoders out there add a small amount of silence to the start/end of the encoded file. This is usually a small amount, around 0.03 seconds. Most of the time it goes unnoticed, BUT when you have tracks that flow into one

Hi folks, some notes about goings on. After opportunity to think aloud, I have the pieces of the VQ system more or less in place. I need to finish the codebook generation core (this is not libvorbis code, but an external utility). I then need to write the encode/ decode/packing code that makes use of the codebook. This future code is already specced. Tony: I haven't worked on the xmms

Hi folks, some notes about goings on. After opportunity to think aloud, I have the pieces of the VQ system more or less in place. I need to finish the codebook generation core (this is not libvorbis code, but an external utility). I then need to write the encode/ decode/packing code that makes use of the codebook. This future code is already specced. Tony: I haven't worked on the xmms

Hi, I am the CTO of an online e-commerce site selling signed underground music. We're just about to begin with mp3 distribution by download. I have looked into Ogg Vorbis, and it is interesting for us to both avoid the mp3 patent stuff (what's the legal status of Fraunhofer looking into any possible patent infringements by Ogg?), and WMA. However, I still don't think Ogg Vorbis is

Hi all, Q1: The source defined this structure in the psy.h file: typedef struct{ int eighth_octave_lines; float preecho_thresh[4]; float postecho_thresh[4]; float preecho_minenergy; float ampmax_att_per_sec; int delaycache; } vorbis_info_psy_global; However, the file psytune.c makes this declaration: tatic vorbis_info_psy_global _psy_set0G={ 0, /* decaydBpms */ 8, /* lines per e...

Hi, all. I'm new to this list, and I know that my question touches on a FAQ. I'm just hoping to get more information than "it's a priority item, but it's not done yet." (Basically what the FAQ says.) I've been encoding about 20 minutes of mono audio each week to as small a file as I can, so it can be served via html. As long as the result is understandable,

Greatly concerned for size, i just ripped an audio cd @ 22050kHz and mono sound. Encoding using 'oggenc -b 1 -', the resulting Ogg file is around 30kb/s. During the encoding process i was "warned" that the encoder is tuned toward 44.1kHz and encoding files in any other may result in degraded quality. How worried should I be? Is the advantage in size lost due to crappy

...re the beta and haven't fixed it yet because it was considered relatively minor; [ironically] it mostly affects test samples with a single strong frequency and no or only regular harmonics. The effects in 'natural' audio are more subtle, although still audible; it sounds like imperfect preecho cancellation (which is partially what it is). A few details so folks are more informed: Our current encoder tries to differentiate between strongly periodic [regular] signals and impulses/strong breaks in the sound (no surprise there). The impulses and strong breaks are coded in shorter blocks (...

I tested Vorbis encoder - beta3 version, and here are my thoughts: - In comparison to beta2, subtle high-frequency artifacts seem to be gone (though they were small in beta2). Good job there! :-) - Velvet.wav also sounds better, but transparent quality is reached at -b256+. - Horn.wav still sounds very sucky, mode -b256 gives ~100kbps (this is understandable because in this sample practically

I was recently talking to a friend of mine who produces what's widely referred to as "techno", music that's heavy on electronically generated loops and effects, samples, and has plenty of bass. He doesn't like ogg for a few reasons - he sent me a rather long email, and I've stripped out the nonsense from it (he has some technically irrelevant reasons for not liking