mpg123 low level I/O

Functions
int	mpg123_replace_buffer (mpg123_handle *mh, unsigned char *data, size_t size)
size_t	mpg123_outblock (mpg123_handle *mh)
int	mpg123_replace_reader (mpg123_handle *mh, ssize_t(*r_read)(int, void *, size_t), off_t(*r_lseek)(int, off_t, int))
int	mpg123_replace_reader_handle (mpg123_handle *mh, ssize_t(*r_read)(void *, void *, size_t), off_t(*r_lseek)(void *, off_t, int), void(*cleanup)(void *))

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Detailed Description

You may want to do tricky stuff with I/O that does not work with mpg123's default file access or you want to make it decode into your own pocket...

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Function Documentation

int mpg123_replace_buffer	(	mpg123_handle *	mh,
		unsigned char *	data,
		size_t	size
	)

Replace default internal buffer with user-supplied buffer. Instead of working on it's own private buffer, mpg123 will directly use the one you provide for storing decoded audio.

size_t mpg123_outblock

(

mpg123_handle *

mh

)

The max size of one frame's decoded output with current settings. Use that to determine an appropriate minimum buffer size for decoding one frame.

int mpg123_replace_reader	(	mpg123_handle *	mh,
		ssize_t(*)(int, void *, size_t)	r_read,
		off_t(*)(int, off_t, int)	r_lseek
	)

Replace low-level stream access functions; read and lseek as known in POSIX. You can use this to make any fancy file opening/closing yourself, using mpg123_open_fd() to set the file descriptor for your read/lseek (doesn't need to be a "real" file descriptor...). Setting a function to NULL means that the default internal read is used (active from next mpg123_open call on). Note: As it would be troublesome to mess with this while having a file open, this implies mpg123_close().

int mpg123_replace_reader_handle	(	mpg123_handle *	mh,
		ssize_t(*)(void *, void *, size_t)	r_read,
		off_t(*)(void *, off_t, int)	r_lseek,
		void(*)(void *)	cleanup
	)

Replace I/O functions with your own ones operating on some kind of handle instead of integer descriptors. The handle is a void pointer, so you can pass any data you want... mpg123_open_handle() is the call you make to use the I/O defined here. There is no fallback to internal read/seek here. Note: As it would be troublesome to mess with this while having a file open, this mpg123_close() is implied here.

Parameters:

	r_read	The callback for reading (behaviour like posix read).
	r_lseek	The callback for seeking (like posix lseek).
	cleanup	A callback to clean up an I/O handle on mpg123_close, can be NULL for none (you take care of cleaning your handles).