Originally posted by Hanky
I played around with the ultralowbitrate clips and I was quite amazed. In some of them there was quite a lot of signalclipping (I did not activate the hard-limiter in the decoder). So I decided to run vorbisgain on the files.
This was one of the results:

D:vorbisbackupultralowbitrate>vorbisgain *.ogg

Processing directory '.':
Analyzing files...

   Gain   |  Peak  | Scale | New Peak | Track
----------+--------+-------+----------+------
-11.45 dB |  51988 |  0.27 |    13912 | scar.ogg
-1.29 dB |  25355 |  0.86 |    21856 | ss.ogg
+0.72 dB |  27163 |  1.09 |    29511 | queen.ogg
-7.17 dB |  43151 |  0.44 |    18901 | waitress.ogg
-7.12 dB |  52190 |  0.44 |    22993 | daan.ogg
Couldn't initialize gain analysis (nonstandard samplerate?) for 'scarres4.ogg'

Does this mean that 6kHz sampling rate does not comply to the standard or is Vorbisgain wrong here ?
I use Vorbisgain 0.32 dated 2002-07-24 from RareWares

// for each filter:

// [0] 48 kHz, [1] 44.1 kHz, [2] 32 kHz, [3] 24 kHz, [4] 22050 Hz, [5] 16 kHz, [6] 12 kHz, [7] is 11025 Hz, [8] 8 kHz



const Float_t  AYule [9] [11] = {

    { 1., -3.84664617118067,  7.81501653005538,-11.34170355132042, 13.05504219327545,-12.28759895145294,  9.48293806319790, -5.87257861775999,  2.75465861874613, -0.86984376593551, 0.13919314567432 },

    { 1., -3.47845948550071,  6.36317777566148, -8.54751527471874,  9.47693607801280, -8.81498681370155,  6.85401540936998, -4.39470996079559,  2.19611684890774, -0.75104302451432, 0.13149317958808 },

    { 1., -2.37898834973084,  2.84868151156327, -2.64577170229825,  2.23697657451713, -1.67148153367602,  1.00595954808547, -0.45953458054983,  0.16378164858596, -0.05032077717131, 0.02347897407020 },

    { 1., -1.61273165137247,  1.07977492259970, -0.25656257754070, -0.16276719120440, -0.22638893773906,  0.39120800788284, -0.22138138954925,  0.04500235387352,  0.02005851806501, 0.00302439095741 },

    { 1., -1.49858979367799,  0.87350271418188,  0.12205022308084, -0.80774944671438,  0.47854794562326, -0.12453458140019, -0.04067510197014,  0.08333755284107, -0.04237348025746, 0.02977207319925 },

    { 1., -0.62820619233671,  0.29661783706366, -0.37256372942400,  0.00213767857124, -0.42029820170918,  0.22199650564824,  0.00613424350682,  0.06747620744683,  0.05784820375801, 0.03222754072173 },

    { 1., -1.04800335126349,  0.29156311971249, -0.26806001042947,  0.00819999645858,  0.45054734505008, -0.33032403314006,  0.06739368333110, -0.04784254229033,  0.01639907836189, 0.01807364323573 },

    { 1., -0.51035327095184, -0.31863563325245, -0.20256413484477,  0.14728154134330,  0.38952639978999, -0.23313271880868, -0.05246019024463, -0.02505961724053,  0.02442357316099, 0.01818801111503 },

    { 1., -0.25049871956020, -0.43193942311114, -0.03424681017675, -0.04678328784242,  0.26408300200955,  0.15113130533216, -0.17556493366449, -0.18823009262115,  0.05477720428674, 0.04704409688120 }

};



const Float_t  BYule [9] [11] = {

    { 0.03857599435200, -0.02160367184185, -0.00123395316851, -0.00009291677959, -0.01655260341619,  0.02161526843274, -0.02074045215285,  0.00594298065125,  0.00306428023191,  0.00012025322027,  0.00288463683916 },

    { 0.05418656406430, -0.02911007808948, -0.00848709379851, -0.00851165645469, -0.00834990904936,  0.02245293253339, -0.02596338512915,  0.01624864962975, -0.00240879051584,  0.00674613682247, -0.00187763777362 },

    { 0.15457299681924, -0.09331049056315, -0.06247880153653,  0.02163541888798, -0.05588393329856,  0.04781476674921,  0.00222312597743,  0.03174092540049, -0.01390589421898,  0.00651420667831, -0.00881362733839 },

    { 0.30296907319327, -0.22613988682123, -0.08587323730772,  0.03282930172664, -0.00915702933434, -0.02364141202522, -0.00584456039913,  0.06276101321749, -0.00000828086748,  0.00205861885564, -0.02950134983287 },

    { 0.33642304856132, -0.25572241425570, -0.11828570177555,  0.11921148675203, -0.07834489609479, -0.00469977914380, -0.00589500224440,  0.05724228140351,  0.00832043980773, -0.01635381384540, -0.01760176568150 },

    { 0.44915256608450, -0.14351757464547, -0.22784394429749, -0.01419140100551,  0.04078262797139, -0.12398163381748,  0.04097565135648,  0.10478503600251, -0.01863887810927, -0.03193428438915,  0.00541907748707 },

    { 0.56619470757641, -0.75464456939302,  0.16242137742230,  0.16744243493672, -0.18901604199609,  0.30931782841830, -0.27562961986224,  0.00647310677246,  0.08647503780351, -0.03788984554840, -0.00588215443421 },

    { 0.58100494960553, -0.53174909058578, -0.14289799034253,  0.17520704835522,  0.02377945217615,  0.15558449135573, -0.25344790059353,  0.01628462406333,  0.06920467763959, -0.03721611395801, -0.00749618797172 },

    { 0.53648789255105, -0.42163034350696, -0.00275953611929,  0.04267842219415, -0.10214864179676,  0.14590772289388, -0.02459864859345, -0.11202315195388, -0.04060034127000,  0.04788665548180, -0.02217936801134 }

};



const Float_t  AButter [9] [3] = {

    { 1., -1.97223372919527, 0.97261396931306 },

    { 1., -1.96977855582618, 0.97022847566350 },

    { 1., -1.95835380975398, 0.95920349965459 },

    { 1., -1.95002759149878, 0.95124613669835 },

    { 1., -1.94561023566527, 0.94705070426118 },

    { 1., -1.92783286977036, 0.93034775234268 },

    { 1., -1.91858953033784, 0.92177618768381 },

    { 1., -1.91542108074780, 0.91885558323625 },

    { 1., -1.88903307939452, 0.89487434461664 }

};



const Float_t  BButter [9] [3] = {

    { 0.98621192462708, -1.97242384925416, 0.98621192462708 },

    { 0.98500175787242, -1.97000351574484, 0.98500175787242 },

    { 0.97938932735214, -1.95877865470428, 0.97938932735214 },

    { 0.97531843204928, -1.95063686409857, 0.97531843204928 },

    { 0.97316523498161, -1.94633046996323, 0.97316523498161 },

    { 0.96454515552826, -1.92909031105652, 0.96454515552826 },

    { 0.96009142950541, -1.92018285901082, 0.96009142950541 },

    { 0.95856916599601, -1.91713833199203, 0.95856916599601 },

    { 0.94597685600279, -1.89195371200558, 0.94597685600279 }

};

Originally posted by rjamorim


Eheh. Come on. The results are indeed amazing, but the quality is so bad anyway that I would throw my player through the window after listening to it for 10 minutes.

Setup an ogg stream (q0 40~45kb/s 22khz )

rexit2.ath.cx:8000/q0.ogg

(seems to be a GREAT alternative to mp3 streaming @ lower bitrates)

Code: [Select]

// for each filter:
//[0] 48 kHz, [1] 44.1 kHz, [2] 32 kHz, [3] 24 kHz, [4] 22050 Hz, [5] 16 kHz, [6] 12 kHz, [7] is 11025 Hz, [8] 8 kHz

I would like to put a CD on a floppy. If you have 2.8M floppies, you can do so already.

Sounds shit but better than most 64kbps mp3's I've heard which lots of people (not on this forum) find to be acceptable quality.

Quote

Code: [Select]

// for each filter:
//[0] 48 kHz, [1] 44.1 kHz, [2] 32 kHz, [3] 24 kHz, [4] 22050 Hz, [5] 16 kHz, [6] 12 kHz, [7] is 11025 Hz, [8] 8 kHz

how about extending the filters' table with coefficients that relevant for 96k, 88.2k & 64k ?

this will be useful in my AACGain..

Code: [Select]

// for each filter:
//[0] 48 kHz, [1] 44.1 kHz, [2] 32 kHz, [3] 24 kHz, [4] 22050 Hz, [5] 16 kHz, [6] 12 kHz, [7] is 11025 Hz, [8] 8 kHz

- Filter coeffs are calculated by 2bdecided
- 64k, 88.2k, 96k, 128k, 176.4k, 192k are possible
- to my mind also the filters are suboptimal. They underestimate the loudness
between 100 and 200 Hz, overestimate <25 Hz
- at home I have a list of 30 used sample frequencies which should be supported

I had a little fun with the Vorbis 1.0 libs, hacked a bit with it, and made some demonstration oggs of what it is capable of at the really low end.

Have a listen to:

http://sjeng.org/ftp/vorbis/scar.ogg  (6.4kbps)
http://sjeng.org/ftp/vorbis/queen.ogg (5.3kbps)
http://sjeng.org/ftp/vorbis/ss.ogg  (6.3kbps)
http://sjeng.org/ftp/vorbis/waitress.ogg (6.7kbps)

Edit: also

http://sjeng.org/ftp/vorbis/daan.ogg (6.6kbps)

And keep in mind this is 1/20'th of an 128kbps file.

--
GCP