Replaygain at high sample rate, currently replaygain only works upto 48 khz |
Replaygain at high sample rate, currently replaygain only works upto 48 khz |
Oct 5 2010, 14:22
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#1
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Group: Members Posts: 3 Joined: 5-October 10 Member No.: 84356 |
Hi,
I noticed that replaygain (as applied by metaflac) only works on tracks with a sample rate upto 48 khz. I'd like to apply it to all my audio files and I do now have some with 88.2, 96, or 192 khz sample rate. Looking into the code I see the following: CODE FLAC__bool grabbag__replaygain_is_valid_sample_frequency(unsigned sample_frequency) { static const unsigned valid_sample_rates[] = { 8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000 }; static const unsigned n_valid_sample_rates = sizeof(valid_sample_rates) / sizeof(valid_sample_rates[0]); unsigned i; for(i = 0; i < n_valid_sample_rates; i++) if(sample_frequency == valid_sample_rates[i]) return true; return false; } In other words, a limit, but it looks as if I could just add other values. However, 96khz would go over the unsigned 16-bit integer limit, so changing to 32-bit integers might be necessary. Would this make anything run into trouble? I've yet to try, which I'll hopefully do later today. Now the guesswork: Have these rates been chosen as commonly used? Is this check at all necessary? Isn't it enough for the sampling rate to be a positive integer? Is this only in the flac implementation or is this part of the proposed replaygain specification? Is the reason for the lack of higher sampling rates that at the time calculation for them would have been very slow (in this case it would be better to put up a warning instead)? Is this because the replaygain reference values are based on psychoacoustics and those are lacking for frequencies we don't hear but which would be present in the higher sampling rate signals? |
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Jan 8 2012, 08:02
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#2
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Group: Members Posts: 1 Joined: 25-April 10 Member No.: 80153 |
I noticed that replaygain (as applied by metaflac) only works on tracks with a sample rate upto 48 khz. See http://lists.xiph.org/pipermail/flac-dev/2...ary/003064.html |
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Jan 9 2012, 21:17
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#3
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![]() Group: Members Posts: 607 Joined: 16-January 09 Member No.: 65630 |
I noticed that replaygain (as applied by metaflac) only works on tracks with a sample rate upto 48 khz. See http://lists.xiph.org/pipermail/flac-dev/2...ary/003064.html From that data seems obvious that Butterworth coefficients are linearly correlated, with slight deviation at 18900 set. So those can be obtained for arbitrary rate Only that Yulewalk are not so obvious just by looking in the data Perhaps with some analytical skills? -------------------- Scripts (mainly foobar2000 related): http://goo.gl/yje3h
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Ernst Replaygain at high sample rate Oct 5 2010, 14:22
[JAZ] unsigned means unsigned int, and unsigned int has ... Oct 5 2010, 18:51
tuffy I think what's missing is a set of equal loudn... Oct 5 2010, 19:01
lvqcl QUOTE (tuffy @ Oct 5 2010, 22:01) I think... Oct 5 2010, 19:19
DVDdoug I'll make a couple of guesses & assumption... Oct 5 2010, 19:09
Ernst QUOTE (DVDdoug @ Oct 5 2010, 20:09) I... Oct 6 2010, 05:23
saratoga QUOTE (Ernst @ Oct 6 2010, 00:23) QUOTE (... Oct 6 2010, 19:01
Nessuno QUOTE (saratoga @ Oct 6 2010, 19:01) QUOT... Jan 8 2012, 10:41
saratoga QUOTE (Nessuno @ Jan 8 2012, 04:41) Pedan... Jan 8 2012, 11:04
Nessuno QUOTE (saratoga @ Jan 8 2012, 11:04) To b... Jan 8 2012, 11:19
Yirkha Some filter coefficients in ReplayGain need to be ... Oct 5 2010, 21:48
Ernst I did get a few higher sampling rates set up in me... Oct 24 2010, 10:13
Wombat When i remember right it was asked a long time ago... Jan 8 2012, 21:08
2Bdecided See...
http://lists.xiph.org/pipermail/flac-dev/2.... Jan 13 2012, 16:44
romor Quote from David's link:
QUOTE The extended ga... Jan 14 2012, 16:53![]() ![]() |
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