ov_read_filter()

declared in "vorbis/vorbisfile.h";

ov_read_filter() is a variant of ov_read(), the main function used to decode a Vorbis file within a loop. It passes the decoded floating point PCM data to the filter specified in the function arguments before converting the data to integer output samples. All other aspects of its behavior are as with ov_read().

long ov_read_filter(OggVorbis_File *vf, char *buffer, int length, int bigendianp, int word, int sgned, int *bitstream, void (*filter)(float **pcm,long channels,long samples,void *filter_param),void *filter_param);

Parameters

vf

A pointer to the OggVorbis_File structure--this is used for ALL the externally visible libvorbisfile functions.

buffer

A pointer to an output buffer. The decoded output is inserted into this buffer.

length

Number of bytes to be read into the buffer. Should be the same size as the buffer. A typical value is 4096.

bigendianp

Specifies big or little endian byte packing. 0 for little endian, 1 for b ig endian. Typical value is 0.

word

Specifies word size. Possible arguments are 1 for 8-bit samples, or 2 or 16-bit samples. Typical value is 2.

sgned

Signed or unsigned data. 0 for unsigned, 1 for signed. Typically 1.

bitstream

A pointer to the number of the current logical bitstream.

filter

Filter function to process float PCM data prior to conversion to interleaved integer output.

filter_param

Data to pass through to the filter function.

Return Values

OV_HOLE

indicates there was an interruption in the data.
(one of: garbage between pages, loss of sync followed by recapture, or a corrupt page)

OV_EBADLINK

indicates that an invalid stream section was supplied to libvorbisfile, or the requested link is corrupt.

0

indicates EOF

n

indicates actual number of bytes read. ov_read() will decode at most one vorbis packet per invocation, so the value returned will generally be less than length.

Notes

Typical usage:

bytes_read = ov_read_filter(&vf, buffer, 4096,0,2,1,&current_section, filter, (void *)filter_data_ptr)