hi

i just spent a lot of time searching the forum for information about gapless playback! so i actually found some articles but nowhere the information i was searching for.

what about gapless playback of wave files? can wave files be cut whereever i want them to be or is there also some special way i have to cut them. i'm asking because i want to split some cd images and i don't know where eac cuts them. at special boundaries or where or not! is a splitted image file the same as if i extract all tracks on their own? i absolutely don't get that topic. i had so much questions. has anyone a good tutorial or some basic information about the structure of a wave file and what happens with this file when burning or extracting.

thanks a lot, bye fabian

Most of the itme, a .wav file is made of a RIFF header followed by raw PCM data. If you use an audio editor to cut the file, you'll be able to cut it anywhere you want.

Assuming nothing went wrong, the split files should be the same as if you had extracted them separately.

Gapless playback is usually only a concern when dealing with lossy encoders, as their algorithms usually introduce a small delay at the beginning of the song.

.wav files can contain all kinds of data (it's similar to the AVI format), but most often they are used to contain PCM data. PCM data is the rawest form of audio data you'll encounter, it consists of a (usually quite long) sequence of samples (which describe the original signal). Each sample represents the signal level at a certain point in time, if enough samples are taken each second it's possible to almost perfectly restore the original signal (up to a certain frequency). The sample rate of a CD is 44100Hz, which means the signal is sampled 44100 times per second.

Also see:
http://doc.hydrogenaudio.org/wikis/hydrogenaudio/PCM
http://doc.hydrogenaudio.org/wikis/hydrogenaudio/NyquistRate
http://doc.hydrogenaudio.org/wikis/hydroge...io/SamplingRate

IIRC, what kjoonlee said is correct, unless the files are to burnt to a CD, in which case they must be split in a specific spot (though for the life of me, I can't remember what it is). If you use Adobe Audition (or the old Cool Edit Pro) there is option to automatically split for CD's.

They have to be split at multiples of 588 samples.

1 sec on a CD is divided into 75 frames, 1 frame = 588 samples.
588 * 75 = 44100
and that brings us back to the samplerate of 44 100 samples per second

hi

First of all "I'm absolutely overwhelmed", so many answers! Thanks, really!

Ok, this time I've got more time to write!

I do know that "stuff" about sample rate and so on, so you needn't care about that! :-)

Some more questions concerning gapless playback:

So, I needn't worry about that 588 sample sectors (I also read about this just before concerning a programme called CDWave or something like this) as long as I juse my wave file just on (or at???) the computer. When I want to burn that file on(to) CD, I have to cut it on a position which is a multiple of 588 samples. right? So I conclude that all CDs I rip (btw. EAC) are already cut on the right position! am I right? What about live concerts when there are no audiable gaps? how are such cds structured? In most cases also those CDs have got track-marks! Does anybody know?

Can anyone of you give me more information why there can be only files of a lenght which is a multiple of 588 samples on a cd???



So now the second question:

Does EAC care about that 588 "limit"? No thats a stupid question! It has to cut where the track-mark is, and if, as you explaind, all files on a cd are a multiple of 588 samples, there isn't anything to care about because those guys who pressed the cd already cut the file propperly. ok when I think about my question concerning live concert cds it's also a stupid one because they simple set the track-mark at/on a position (X*588). right?

one final question:

When all cds are stuctured that way, why do people worry that mp3 doesn't support gapless playback? All files on the CD are the right size!?!?

bye and best regards fabian