Is PCM Wave = WAV??

[Stecchino]

I want to buy a particular song from a music website. The site gives me the option to download it in various lossless formats (including Monkey's Audio, FLAC, OptimFROG, WMA 9, and PCM Wave).

I need the format to be compatible with iTunes.

One of the lossless options for downloading is "PCM Wave." Is this the same thing as a file with .WAV at the end of it (which is compatible with iTunes)?

If not, which of these formats would be easily convertible to .AIFF or .WAV in order to be compatible with iTunes? Thanks so much!

 

[Fish Tank X]

PCM is the lossless method that is used to store audio, and is essentially the same as WAV

You should be able to convert it to AIFF.

 

[DanT]

For all practical reason yes PCM is a .wav files. You're going to download a .wav files if you chose PCM wave

Technicaly they are not the same thing at all. PCM (Pulse Code Modulation) is a technique use to represent analog sound in digital form. The data on CD are in PCM form as most wav files. Wav is a file format. Is just a container to store the data in a way that readable by windows. Most wav has PCM data in it but In fact nothing prevent you to mp3 encoded data inside a wav filesformat it's perfectly fine and readable by windows.

An analogy is the question is a book(Wav) the same thing as writting(PCM)? In a bookstore they sell some novel only writing format or in audio format but I want a book.

 

[recephasan]

Quote:

Originally Posted by Fish Tank X PCM is the lossless method that is used to store audio, and is essentially the same as WAV You should be able to convert it to AIFF.

lossless... if only that were true

 

[breez]

Quote:

Originally Posted by recephasan lossless... if only that were true

It's lossless to what you input it

Bits come in and out the same.

omg, teh world is lossy

 

[DanT]

Quote:

Originally Posted by breez It's lossless to what you input it Bits come in and out the same. omg, teh world is lossy

It's not lossless. Because when we talk about lossless we usualy mean encoding. So when do you encode in pcm? If your only transfering (cd to computer) there is no encoding the same data is there. It's like saying I copy my mp3 from my hard drive to my ipod It didn't lose any data so it's lossless well true a mp3 transfer is lossless.

The most common time to encode pcm is from an analog sound, a higer bitrate pcm 96hz/24 bits for example or maybe from an DSD stream all those are lossy.

 

[breez]

You know what... You are right

 

[blessingx]

I wish the had sites like that over here in Russia!

 

[jefemeister]

You can usually convert a .wav file into a .pcm file by simply stripping off the first 44 bytes which is just a header with sample rate info etc. They header length can vary, but I've only seen 44 byte headers. Be careful of "conversion utilities" out there that claim to be able to convert file formats. I know that both Audacity and Goldwave do not handle near-full scale (amplitude) files correctly and will force all digital code within these near full scale regions to be even, when half of them are supposed to be odd.

 

[gaboo]

Quote:

Originally Posted by jefemeister I know that both Audacity and Goldwave do not handle near-full scale (amplitude) files correctly and will force all digital code within these near full scale regions to be even, when half of them are supposed to be odd.

Can you elaborate on that?

 

[jefemeister]

Quote:

Originally Posted by gaboo Can you elaborate on that?

Sure,

I might be a little off on the exact signal modifications but this is best of what I remember. Goldwave doesn't represent -32768 correcly and forces this value to -32767. Audacity forces the least significant bit of the top and bottom 32 values to 0, effectively losing a bit of resolution at near-full scale. This is strictly for their .pcm to/from .wav conversion features. I make no claim for playback, file save, etc.

The background: A few weeks ago I wasted an entire day looking at TI DSP errata sheets because I couldn't figure out why one of the peripherals was messing with the least most significant bit of my data. Finally, I decided to check if the problem was actually in the utility I was using to convert pcm into wav files (I like to use matlab's wavread function to analyze data). Of course it was. We've now developed out own utilites that simply strip/addend header files and leaves the data alone.

 

[gaboo]

Interesting. I'm sure you can get the fokes developing audacity to fix it rather quickly by submitting a bug report (or even better a patch) to audacity-help@lists.sourceforge.net.

 

[jefemeister]

Quote:

Originally Posted by gaboo Interesting. I'm sure you can get the fokes developing audacity to fix it rather quickly by submitting a bug report (or even better a patch) to audacity-help@lists.sourceforge.net.

good suggestion. I'll do that.

 

[Stecchino]

Quote:

Originally Posted by DanT For all practical reason yes PCM is a .wav files. You're going to download a .wav files if you chose PCM wave Technicaly they are not the same thing at all. PCM (Pulse Code Modulation) is a technique use to represent analog sound in digital form. The data on CD are in PCM form as most wav files. Wav is a file format. Is just a container to store the data in a way that readable by windows. Most wav has PCM data in it but In fact nothing prevent you to mp3 encoded data inside a wav filesformat it's perfectly fine and readable by windows. An analogy is the question is a book(Wav) the same thing as writting(PCM)? In a bookstore they sell some novel only writing format or in audio format but I want a book.

Thanks for your input everyone. I downloaded the song in what the store called "PCM Wave" format. It was a .WAV file. I was happy because it didn't require any further conversion or manipulation to import it into iTunes.

I also learned a bit more about the .WAV format and PCM in general as well as getting my question answered.

 

[Stecchino]

Quote:

Originally Posted by blessingx I wish the had sites like that over here in Russia!

FYI, I downloaded that song from a Russian music site.