Re: Coreaudio-api Digest, Vol 2, Issue 63
Re: Coreaudio-api Digest, Vol 2, Issue 63
- Subject: Re: Coreaudio-api Digest, Vol 2, Issue 63
- From: Craig Bakalian <email@hidden>
- Date: Sat, 26 Feb 2005 17:17:11 -0500
Hi,
I get what you are saying, but in practice do you know of any C code,
or C++ code that pushes the MIDIDataChunk into a AIFF file. I guess I
am looking for an example. And, It would be really great if the
example involved CoreAudio.
Anybody?
Craig Bakalian
www.eThinkingCap.com
On Feb 26, 2005, at 3:04 PM, email@hidden
wrote:
Hi,
After some gleaning and careful reading I have come to the conclusion
that it
is possible to get MIDI data into a AIFF file. Yet, I do not know
how to do
it, especially with CoreAudio. I understand that this is the
structure that
must be made
#define MIDIDataID 'MIDI'
type struct{
ID chunkID;
long chunkSize;
unsigned char MIDIdata[ ];
} MIDIDataChunk;
ID is 4 ASCII bytes "described by Interchange File Format". But,
now what?
Does anyone have any other information about pushing MIDI data into
an AIFF
file?
Hi Craig
Apologies for a 'non-answer answer', but MIDI files are also chunked
data. You
would just write to an AIFF file the MIDI chunkID, the size of the
MIDI file,
and then stream the MIDI file into the AIFF.
If you don't have code to generate a MIDI file in memory, you could
write a
simple program to open an AIFF file for writing, open a MIDI file for
reading,
then append the MIDI data into the AIFF.
MIDI files will typically start with a short 'MThd' chunk, followed by
other
chunks, especially 'MT
rk' chunks. A MIDI player needs to know how to parse the chunks, but
for merging
into an AIFF, I think you would just splice the entire thing in
without worrying
about the MIDI file's internal structure.
The AIFF MIDI header chunkSize will instruct any AIFF reading program
how many
bytes to 'jump over' if the program is not interested in that MIDI
file data. In
that way, an Audio-only AIFF program can safely ignore (or preserve
without
supporting) any file chunk it doesn't care about, without needing to
know
anything about the data format in that 'uninteresting' chunk.
JCJR
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden