# Oggz Read API

Oggz parses Ogg bitstreams, forming ogg_packet structures, and calling your OggzReadPacket callback(s). More...

## Typedefs
typedef int(* | OggzReadPacket )(OGGZ *oggz, oggz_packet *packet, long serialno, void *user_data)
| This is the signature of a callback which you must provide for Oggz to call whenever it finds a new packet in the Ogg stream associated with oggz.
typedef int(* | OggzReadPage )(OGGZ *oggz, const ogg_page *og, long serialno, void *user_data)
| This is the signature of a callback which you must provide for Oggz to call whenever it finds a new page in the Ogg stream associated with oggz.
## Functions
int | oggz_set_read_callback (OGGZ *oggz, long serialno, OggzReadPacket read_packet, void *user_data)
| Set a callback for Oggz to call when a new Ogg packet is found in the stream.
int | oggz_set_read_page (OGGZ *oggz, long serialno, OggzReadPage read_page, void *user_data)
| Set a callback for Oggz to call when a new Ogg page is found in the stream.
long | oggz_read (OGGZ *oggz, long n)
| Read n bytes into oggz, calling any read callbacks on the fly.
long | oggz_read_input (OGGZ *oggz, unsigned char *buf, long n)
| Input data into oggz.

## Detailed Description

Oggz parses Ogg bitstreams, forming ogg_packet structures, and calling your OggzReadPacket callback(s).

You provide Ogg data to Oggz with oggz_read() or oggz_read_input(), and independently process it in OggzReadPacket callbacks. It is possible to set a different callback per serialno (ie. for each logical bitstream in the Ogg bitstream - see the Ogg basics section for more detail).

When using an OGGZ* opened with the OGGZ_AUTO flag set, Oggz will internally calculate the granulepos for each packet, even though these are not all recorded in the file: only the last packet ending on a page will have its granulepos recorded in the page header. Within a OggzReadPacket callback, calling oggz_tell_granulepos() will retrieve the calculated granulepos.

See Oggz Seek API for information on seeking on interleaved Ogg data, and for working with calculated granulepos values.

## Typedef Documentation

typedef int(* OggzReadPacket)(OGGZ *oggz, oggz_packet *packet, long serialno, void *user_data)

This is the signature of a callback which you must provide for Oggz to call whenever it finds a new packet in the Ogg stream associated with oggz.

Parameters:

  | oggz | The OGGZ handle
  | packet | The packet, including its position in the stream.
  | serialno | Identify the logical bistream in oggz that contains packet
  | user_data | A generic pointer you have provided earlier

Returns:
  0 to continue, non-zero to instruct Oggz to stop.

Note:
  It is possible to provide different callbacks per logical bitstream -- see oggz_set_read_callback() for more information.

typedef int(* OggzReadPage)(OGGZ *oggz, const ogg_page *og, long serialno, void *user_data)

This is the signature of a callback which you must provide for Oggz to call whenever it finds a new page in the Ogg stream associated with oggz.

Parameters:

  | oggz | The OGGZ handle
  | op | The full ogg_page (see <ogg/ogg.h>)
  | user_data | A generic pointer you have provided earlier

Returns:
  0 to continue, non-zero to instruct Oggz to stop.

## Function Documentation

long oggz_read | ( | OGGZ * | oggz,
|  | long | n |
| ) |  |  |

Read n bytes into oggz, calling any read callbacks on the fly.

Parameters:

  | oggz | An OGGZ handle previously opened for reading
  | n | A count of bytes to ingest

Return values:

  | > 0 | The number of bytes successfully ingested.
  | 0 | End of file
  | OGGZ_ERR_BAD_OGGZ | oggz does not refer to an existing OGGZ
  | OGGZ_ERR_INVALID | Operation not suitable for this OGGZ
  | OGGZ_ERR_SYSTEM | System error; check errno for details
  | OGGZ_ERR_STOP_OK | Reading was stopped by a user callback returning OGGZ_STOP_OK
  | OGGZ_ERR_STOP_ERR | Reading was stopped by a user callback returning OGGZ_STOP_ERR
  | OGGZ_ERR_HOLE_IN_DATA | Hole (sequence number gap) detected in input data
  | OGGZ_ERR_OUT_OF_MEMORY | Out of memory

long oggz_read_input | ( | OGGZ * | oggz,
|  | unsigned char * | buf,
|  | long | n |
| ) |  |  |

Input data into oggz.

Parameters:

  | oggz | An OGGZ handle previously opened for reading
  | buf | A memory buffer
  | n | A count of bytes to input

Return values:

  | > 0 | The number of bytes successfully ingested.
  | OGGZ_ERR_BAD_OGGZ | oggz does not refer to an existing OGGZ
  | OGGZ_ERR_INVALID | Operation not suitable for this OGGZ
  | OGGZ_ERR_STOP_OK | Reading was stopped by a user callback returning OGGZ_STOP_OK
  | OGGZ_ERR_STOP_ERR | Reading was stopped by a user callback returning OGGZ_STOP_ERR
  | OGGZ_ERR_HOLE_IN_DATA | Hole (sequence number gap) detected in input data
  | OGGZ_ERR_OUT_OF_MEMORY | Out of memory

int oggz_set_read_callback | ( | OGGZ * | oggz,
|  | long | serialno,
|  | OggzReadPacket | read_packet,
|  | void * | user_data |
| ) |  |  |

Set a callback for Oggz to call when a new Ogg packet is found in the stream.

Parameters:

  | oggz | An OGGZ handle previously opened for reading
  | serialno | Identify the logical bitstream in oggz to attach this callback to, or -1 to attach this callback to all unattached logical bitstreams in oggz.
  | read_packet | Your callback function
  | user_data | Arbitrary data you wish to pass to your callback

Return values:

  | 0 | Success
  | OGGZ_ERR_BAD_SERIALNO | serialno does not identify an existing logical bitstream in oggz.
  | OGGZ_ERR_BAD_OGGZ | oggz does not refer to an existing OGGZ
  | OGGZ_ERR_INVALID | Operation not suitable for this OGGZ
  | OGGZ_ERR_OUT_OF_MEMORY | Out of memory

Note:
  Values of serialno other than -1 allows you to specify different callback functions for each logical bitstream.

  It is safe to call this callback from within an OggzReadPacket function, in order to specify that subsequent packets should be handled by a different OggzReadPacket function.

int oggz_set_read_page | ( | OGGZ * | oggz,
|  | long | serialno,
|  | OggzReadPage | read_page,
|  | void * | user_data |
| ) |  |  |

Set a callback for Oggz to call when a new Ogg page is found in the stream.

Parameters:

  | oggz | An OGGZ handle previously opened for reading
  | serialno | Identify the logical bitstream in oggz to attach this callback to, or -1 to attach this callback to all unattached logical bitstreams in oggz.
  | read_page | Your OggzReadPage callback function
  | user_data | Arbitrary data you wish to pass to your callback

Return values:

  | 0 | Success
  | OGGZ_ERR_BAD_OGGZ | oggz does not refer to an existing OGGZ
  | OGGZ_ERR_INVALID | Operation not suitable for this OGGZ
  | OGGZ_ERR_OUT_OF_MEMORY | Out of memory

Note:
  Values of serialno other than -1 allows you to specify different callback functions for each logical bitstream.

  It is safe to call this callback from within an OggzReadPage function, in order to specify that subsequent pages should be handled by a different OggzReadPage function.