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Hydrogenaudio Forums > Lossy Audio Compression > MP3 > MP3 - General
NatGun
i get gaps between mp3s that are supposed to flow from one to another seamlessly on a CD. when decode these mp3s to wav and burn them to a disk, the gaps get worse. could the offset correction feature in EAC eliminate these gaps?
paranoos
I suspect that when you're burning the CD, you're using the default gap size of 2 seconds. To the unexperienced user, this may look normal, but let me explain what is happening.

When you rip the CD, the gaps are actually appended to the tracks, so that there is blank space at the end of all your WAV and MP3 files. The reason for this is that some albums actually put music in the gap space, so I don't suggest removing the gaps.

In your case, you have mp3s that are supposed to be played back without gaps, and the burning software is putting 2 seconds between each song. The reason there are gaps in the mp3 playback (with winamp or whatever) is that mp3s are not gapless, although I'm pretty sure that decoding them to WAV will fix this, as you are doing. Still, you need to get rid of the gaps while burning.

So the solution is, while setting up the songs to burn, change the gap length between tracks to 0s. As a note, the first track ALWAYS requires 2 seconds of gap... this isn't a gap that is played, but rather a format standard.

The way to change the gaps depends on what software you are using, and I'm sure there are many programs which do not allow it, which means you need to find a different program, at least for burning audio discs. If this is the case, perhaps somebody else can help with suggestions, as I am a GNU/Linux user wink.gif
minix
QUOTE (paranoos @ Sep 26 2003, 04:36 AM)
So the solution is, while setting up the songs to burn, change the gap length between tracks to 0s. As a note, the first track ALWAYS requires 2 seconds of gap... this isn't a gap that is played, but rather a format standard.

No.
MP3 format usually adds little silences at the beginning and end of files.
You have to manually remove those silences with an editor, and then burning them with a program like Feurio, Sequoia, Samplitude or WaveLab (they can burn tracks not multiple of 588 samples without pauses, unlike most burning programs).

Offsets are not a problem in this case!
Configuring them won't improve the situation.


More threads:
http://www.hydrogenaudio.org/forums/index....showtopic=13351
http://www.hydrogenaudio.org/forums/index.php?showtopic=9004
NatGun
ok so is there any way i can get rid of these gaps? i know there are some settings that delete leading and trailing silences, can this be done during encoding? also, should i even bother with the offsett correction in EAC? is this not needed with lame?
minix
QUOTE (NatGun @ Sep 26 2003, 08:49 PM)
i know there are some settings that delete leading and trailing silences, can this be done during encoding?

You can't do it in the encoding process because of the frames problem, I guess: An MP3 file has an integer number of frames, and if the end of track doesn't occur at the same time as the end of the frame, then that last frame needs to be filled with silence.
I think that LAME has a "nogap" option (and also Blade encoder), but it was buggy some time ago. Search the forum about this "nogap" option.

(The settings for deleting leadind and trailing silences only work perfectly with WAV files because of the limitations of MP3 format).


You can fix the problem after decoding or while decoding.
I think that Foobar has an option to decode gaplessly, at least if the MP3 files are encoded with the latest LAME versions.

After that, those WAV files decoded by Foobar or the WAVs edited by you (maybe WavTrim can be helpful here?), have to be burned with one of those few programs named before (and proper pauses settings).


QUOTE
should i even bother with the offsett correction in EAC?

No.
Offset won't make a difference when listening the tracks. This is an issue if the offset of your drive is relatively big and you make copies of the copies of the copies and so on... (finally the tracks will be too much shifted).
AtaqueEG
QUOTE (minix @ Sep 26 2003, 02:22 PM)
You can't do it in the encoding process because of the frames problem, I guess: An MP3 file has an integer number of frames, and if the end of track doesn't occur at the same time as the end of the frame, then that last frame needs to be filled with silence.


You are right

QUOTE
I think that LAME has a "nogap" option (and also Blade encoder), but it was buggy some time ago. Search the forum about this "nogap" option.


QUOTE
(The settings for deleting leadind and trailing silences only work perfectly with WAV files because of the limitations of MP3 format)


You are right, also

QUOTE
You can fix the problem after decoding or while decoding.
I think that Foobar has an option to decode gaplessly, at least if the MP3 files are encoded with the latest LAME versions.


Not quite.
foobar2000 has no option to decode MP3 gaplessly, it just does it! That is, if your files were encoded using the latest LAME versions (don' t exactly know which ones, but the recommended compiles would do). Do not alter anything in EAC, as it could be counterproductive. Do not select "delete leading and trailing silence", it willl not help on CDs that are already mastered to flow seamlessly between tracks. Forget about offsets also, they are not the problem.
Whenever you want to burn a CD from MP3 (I don't think downloaded files will work), just load them in foobar2000, select them all and right click. Select "Convert-->Run conversion" and you are set (you can also configure foobar2000 to apply ReplayGain and dithering, which is very recommended on MP3 files).
Then, load the resulting wav files on your burning software of choice and burn (make sure to disable gaps when burning)
This will work 100%.
minix
QUOTE (AtaqueEG @ Sep 27 2003, 01:58 AM)
Whenever you want to burn a CD from MP3 (I don't think downloaded files will work), just load them in foobar2000, select them all and right click. Select "Convert-->Run conversion" and you are set.

Alright.
Does that gapless function only work with the latest LAME versions?
I've never tried Foobar, so I don't know. I thought that maybe there were options to not play the small silences in every kind of MP3 file.


QUOTE
Then, load the resulting wav files on your burning software of choice and burn (make sure to disable gaps when burning)
This will work 100%.

You can't use your burning software of choice.
Only Feurio, Sequoia, Samplitude or WaveLab.
The rest of the programs will introduce small silences at the end of the track to fill the last sector, which can be as big as 587 samples (13ms).

That is because the length of the decoded MP3 file won't be a multiple of the size of a CD-DA track.
AtaqueEG
QUOTE (minix @ Sep 26 2003, 08:19 PM)
You can't use your burning software of choice.
Only Feurio, Sequoia, Samplitude or WaveLab.
The rest of the programs will introduce small silences at the end of the track to fill the last sector, which can be as big as 587 samples (13ms).

That is because the length of the decoded MP3 file won't be a multiple of the size of a CD-DA track.

Trust me, it will work.

foobar2000 will produce decoded files that match the length of the original file (and if the original was ripped from CD, then it is already cut to fit frame sizes)
minix
QUOTE (AtaqueEG @ Sep 27 2003, 05:07 AM)
Trust me, it will work.

It doesn't work for me blink.gif
foobar2k doesn't even remove the silences.
I've compressed to MP3 with one the LAME_ENC.DLL 3.90.3 compiles at rarewares, and then decoded with foobar2k with no setting changed (installed now).
minix
OK.
It doesn't work with MP3 files encoded with lame_enc.dll, but it works perfectly fine with LAME.EXE as you said. The decoded WAVs have the same size as the original tracks. Great smile.gif

Therefore, we have two options.
If the MP3s are encoded with latest versions of LAME.EXE, we can decode with foobar2k and burn with any program.
Otherwise, we'll have to remove the silences manually and burn with specialized programs.
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