OK. I’m trying to learn about audio and compression. I have a fundamental question that I haven’t found the answer to yet scouring the internet.
I know that there are self describing formats with header information. If I convert different files into “raw” format with sox, am I wrong in thinking that gives them the same number of “channels” and “sample rate”?
I guess I was thinking that raw would be the great “neutralizer.” Is this not the case? Like you could treat all files as if they were the same if they were in raw format?
Wikipedia says…
RAW Audio format or just RAW Audio is
a computer format for storing
uncompressed audio in raw form.
Comparable to WAV or AIFF in size, RAW
Audio file does not include any header
information (sampling rate, bit depth,
endian, or number of channels). Data
can be written in PCM, IEEE 754 or
ASCII.[citation needed]
There is also some good information on file format in general at http://en.wikipedia.org/wiki/Audio_file_format
Clarification
I need to concatenate mp3 files that may start out with different numbers of channels and sampling rates. I don’t honestly know how many channels I want to end up with. I am trying to combine the different files with sox. However, sox needs the files be in the same file format. So, I was hoping to get them in the “same file format” meaning the same number of channels and sampling rate.
However, now it seems that raw might just these two items but remove the self describing header information? In other words, an mp3 file converted to raw, retains the same properties (sampling rate and number of channels)?
What you want to do is:
RAW-files are the same as WAV-files, only that they have no header that tells you the format. So you can completely forget about RAW-files unless you happen to know the audio format of the file anyway, and therefore don’t need that header information.