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Any encoders which will 'accept but crop' too high resolution , ... so that the user will notice that not all formats are equal?
Porcus
post Jan 3 2011, 17:22
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Q: Will all (at least all widely used) 'lossless' audio encoders abort with the appropriate error message if the user tries to feed unsupported audio? Or is there any which will discard channels, downsample, crop bits or just produce nonsense?


The reason why I ask, is that this forum fairly often gets the n00b question of whether 'lossless' is indeed lossless -- and get no more than a simple 'Yes' (or 'Yes, thread closed'). The devil in the detail is hardly ever mentioned, and most users will anyway never encounter that mismatch. But if the situation is 'in the few instances where the usual answer is inadequate, the encoder will warn the users rather than eating audio information', it would certainly be A Good Thing.


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googlebot
post Jan 4 2011, 10:41
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I stand corrected by practice, it seems.

I still think that Foobar or the Flac encoder is far from behaving as it should, here, and that this rather belongs into a bug report than into the Flac Wiki. In programming there is no implicit Float->Int conversion. So an explicit conversion is happening here - this is where the information loss occurs (not in the encoder) - and the developer is not telling you about it! It's only slightly less worse in the 32 bit integer case, where the 8 LSB are probably just omitted without checking whether they are empty.

Float preservation is hard to accomplish. It's not impossible, though. Developers must just not rely on a specific hardware's float capabilities for the correctness of their program.

QUOTE (Porcus @ Jan 4 2011, 09:53) *


This is seems to be a common range offset bug (start counting from 0 instead of 1 and vice versa). While this is certainly annoying and a sign of bad QA, the same could basically happen to any WAV implementation. It is not specifically related to the math of lossless compression.

This post has been edited by googlebot: Jan 4 2011, 11:17
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Posts in this topic
- Porcus   Any encoders which will 'accept but crop' too high resolution   Jan 3 2011, 17:22
- - googlebot   QUOTE (Porcus @ Jan 3 2011, 17:22) The de...   Jan 3 2011, 18:41
|- - MichaelW   QUOTE (googlebot @ Jan 4 2011, 06:41) der...   Jan 3 2011, 23:15
- - googlebot   I agree that stuff like this is happening in the f...   Jan 3 2011, 23:51
- - Robertina   With foobar2000 1.1.1 and flac encoder 1.2.1b:Sour...   Jan 4 2011, 01:19
|- - saratoga   QUOTE (Robertina @ Jan 3 2011, 19:19) Wit...   Jan 4 2011, 01:49
|- - Robertina   QUOTE (saratoga @ Jan 3 2011, 13:49) Sinc...   Jan 4 2011, 01:55
|- - Robertina   QUOTE (saratoga @ Jan 3 2011, 13:49) Sinc...   Jan 4 2011, 03:37
||- - saratoga   QUOTE (Robertina @ Jan 3 2011, 21:37) Doe...   Jan 4 2011, 05:06
||- - 2Bdecided   QUOTE (saratoga @ Jan 4 2011, 04:06) Floa...   Jan 4 2011, 13:02
||- - saratoga   QUOTE (2Bdecided @ Jan 4 2011, 07:02) QUO...   Jan 4 2011, 19:55
||- - lvqcl   QUOTE (saratoga @ Jan 4 2011, 21:55) I th...   Jan 4 2011, 20:22
|||- - saratoga   QUOTE (lvqcl @ Jan 4 2011, 14:22) QUOTE (...   Jan 4 2011, 20:39
|||- - googlebot   QUOTE (saratoga @ Jan 4 2011, 20:39) I th...   Jan 5 2011, 02:00
||- - 2Bdecided   QUOTE (saratoga @ Jan 4 2011, 18:55) The ...   Jan 5 2011, 11:59
|- - Porcus   QUOTE (saratoga @ Jan 4 2011, 01:49) Sinc...   Jan 4 2011, 09:51
|- - Porcus   QUOTE (Porcus @ Jan 4 2011, 09:51) encode...   Jan 4 2011, 09:53
- - Axon   FWIW, AFAIK, neither flac.exe nor foobar2000 warns...   Jan 4 2011, 01:21
- - Robertina   Thank you for your clarification, saratoga. -----...   Jan 4 2011, 08:26
- - googlebot   I stand corrected by practice, it seems. I still ...   Jan 4 2011, 10:41
|- - Robertina   QUOTE (googlebot @ Jan 3 2011, 22:41) I s...   Jan 4 2011, 11:50
|- - lvqcl   QUOTE (Robertina @ Jan 4 2011, 13:50) I t...   Jan 4 2011, 12:27
|- - googlebot   QUOTE (Robertina @ Jan 4 2011, 11:50) I t...   Jan 4 2011, 12:27
- - Robertina   Thank you for your full answer , googlebot. QUOTE...   Jan 4 2011, 15:32
- - lvqcl   f32.wav: 32-bit floating point. CODEf32.wav: E...   Jan 4 2011, 15:48
- - lvqcl   By the way, WavPack accepts 32-bit integer files, ...   Jan 4 2011, 16:14
|- - Robertina   QUOTE (lvqcl @ Jan 4 2011, 04:14) By the ...   Jan 4 2011, 17:02
- - lvqcl   That's probably because foobar2000 converts ev...   Jan 4 2011, 17:10
- - Robertina   I am not really happy with what I have learned in ...   Jan 4 2011, 17:37
- - googlebot   32 bit float values can safely store 24 bit int sa...   Jan 4 2011, 17:50
- - googlebot   AFAIK the meaning is well defined. Just the precis...   Jan 4 2011, 20:04
- - lvqcl   Both compressing and decompressing can be performe...   Jan 4 2011, 21:11
- - Axon   Certainly doing anything meaningful with floating ...   Jan 4 2011, 21:49
- - indybrett   I recall years ago reading (on this board) about n...   Jan 4 2011, 22:22
- - lvqcl   FLAC has --keep-foreign-metadata switch: QUOTE If ...   Jan 4 2011, 22:28
|- - indybrett   QUOTE (lvqcl @ Jan 4 2011, 16:28) FLAC ha...   Jan 4 2011, 22:31
|- - greynol   QUOTE (indybrett @ Jan 4 2011, 13:31) or ...   Jan 4 2011, 22:50
- - greynol   That's not really on-topic but... It was with...   Jan 4 2011, 22:31
- - Porcus   Even though I originally asked about encoders, I d...   Jan 5 2011, 00:54
- - Axon   For that matter, IIRC, since IEEE 754 demands norm...   Jan 5 2011, 02:37
- - bryant   Id like to clarify a couple things about WavPack ...   Jan 5 2011, 21:32


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