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17th August 2017, 00:02 | #5 | Link |
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VorbisGain does exist for flag based (lossless) normalization.
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17th August 2017, 00:54 | #6 | Link | |
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Last edited by kolamorx; 17th August 2017 at 00:56. |
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17th August 2017, 05:40 | #9 | Link | |
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Foorbar2000 can losslessly adjust MP3 and AAC as MP3Gain does. I don't know of any way to adjust ogg files losslessly. You'd have to scan them, add the ReplayGain info to the tags, then convert to ogg or some other format while applying the ReplayGain info. Foobar2000 can do that. |
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17th August 2017, 10:28 | #10 | Link |
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Of course, is the only method without a lossy decode/recode conversion.
Despite the hello_hello comment ReplayGain, VorbisGain and Foobar2000 claim than OGG files support that method without recode. If you use a standalone player you need check if it support the method.
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19th August 2017, 19:13 | #11 | Link |
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Just came across replaygain parameter of FFmpeg volume filter. What exactly does it do?
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20th August 2017, 19:13 | #13 | Link | |
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Mind you, I wouldn't have thought adding ReplayGain info to tags counted as a lossless adjustment as such, given it only provides instructions for a player to adjust it's volume and doesn't change the volume of the audio itself. Foobar2000 will scan and add ReplayGain info to just about any audio/file type these days. AC3, raw AAC, MP4, M4A, DTS, WAVE, FLAC, MKA, MPC, OGG, WavPack, AIFF, WMA, MP2, MP3.... I assume most of the previously mentioned scanning options use the original ReplayGain scanning algorithm. Foobar2000 uses the newer EBU R128 algorithm for ReplayGain scanning which seems more accurate. What does ffmpeg use these days? Anyone know? Last edited by hello_hello; 20th August 2017 at 19:33. |
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21st August 2017, 16:13 | #14 | Link |
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There are ebur128 and loudnorm (possibly more) in ffmpeg today (r128 based i mean). Of corse docs are historically sparse and without examples, so good luck at constructing your cli.
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certain other member Last edited by smok3; 21st August 2017 at 16:20. |
24th August 2017, 08:27 | #15 | Link | |
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They way lossless volume adjustment for MP3 and AAC files works is with flags too. I remember MP3 players back in the day that didn't respect MP3's volume flags but now support seems universal. I have no idea how universal support is for Vorbis flags.
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24th August 2017, 22:09 | #17 | Link | ||
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MP3DirectCut will even apply fade-ins and fade-outs to MP3s without re-encoding. The flags they use must be quite detailed. The way I understand it, each MP3 frame includes some sort of volume information, so an MP3 can have it's volume adjusted by altering the data in each frame. That must be pretty close to the definition of a lossless adjustment. Roughly two thirds of the way down the page (MP3 tag spec): http://gabriel.mp3-tech.org/mp3infotag.html Quote:
0008D5 Stereo mode: 3 (0x3) - (3 bits) 0008D5 noise shapings: 1 (0x1) - (2 bits) 0008D6 MP3 Gain: 0 (0x00) 0008D7 Preset and surround info: 480 (0x01E0) 0008D9 MusicLength: 5087909 0x004DA2A5) I'm not sure I can see any other field for storing volume information. Are you referring to something else? I brewed a fresh MP3, scanned it and adjusted it's volume with foobar2000 and had a look at it's tag, but it seems foobar200 doesn't write the MP3Gain info either. 00094B Stereo mode: 3 (0x3) - (3 bits) 00094B noise shapings: 1 (0x1) - (2 bits) 00094C MP3 Gain: 0 (0x00) 00094D Preset and surround info: 480 (0x01E0) 00094F MusicLength: 4618468 (0x004678E4) Last edited by hello_hello; 24th August 2017 at 22:12. |
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24th August 2017, 22:25 | #18 | Link |
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There are different things. The "actual" adjustment is made in each frame in "global_gain" element (MediaInfo shows this). Then mp3gain may also add APEv2 tags to undo adjustment or make it more precise (global_gain is 1.5 dB steps).
There is no reserved space for either global_gain or APEv2. global_gain is always present in every mp3 file. Just needs to be altered. The (optional) APEv2 tag will be added. |
25th August 2017, 10:05 | #19 | Link | ||
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There's no law stating the global_gain value for each frame must be adjusted by the same amount, which is why MP3DirectCut can change the volume of specific parts of an MP3 or apply fade-ins and fade-outs etc. Quote:
Is there also some other definition of "logging a volume adjustment" that'd only apply in this case? http://gabriel.mp3-tech.org/mp3infotag.html byte $B5 MP3 Gain any mp3 can be amplified by a factor 2 ^ ( x * 0.25) in a lossless manner by a tool like eg. mp3gain byte $B5 is set to (00)h by default. if done so, this 8-bit field can be used to log such transformation happened so that any given time it can be undone. I still don't know which volume flag Asmodian referred to. Was there a time MP3 players ignored the global_gain of each frame? It sounded to me like he was referring to some sort of "master volume" flag, but aside from the possibility of using the ReplayGain field in the MP3 header, which is far as I know isn't widely supported by players, I don't know what field/flag that'd be. Last edited by hello_hello; 25th August 2017 at 10:09. |
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25th August 2017, 10:15 | #20 | Link | ||
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I highly doubt that. |
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