ogg_afh_common.h

   1 /* Copyright (C) 2010 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /**
   4  * \file ogg_afh_common.h Structures and prototypes common to audio format
   5  * handlers that use the ogg container format.
   6  */
   7
   8 struct oac_custom_header *oac_custom_header_new(void);
   9 void oac_custom_header_init(int serial, struct oac_custom_header *h);
  10 int oac_custom_header_append(ogg_packet *op, struct oac_custom_header *h);
  11 void oac_custom_header_flush(struct oac_custom_header *h);
  12 size_t oac_custom_header_get(char **buf, struct oac_custom_header *h);
  13
  14 /**
  15  * Callback structure provided by audio format handlers.
  16  *
  17  * All audio formats which utilize the ogg container format define a callback
  18  * function whose purpose is to extract the meta information about the audio
  19  * file from the first few ogg packets of the bitstream.
  20  */
  21 struct oac_callback_info {
  22         /**
  23          * ogg_get_file_info() calls this function for the first three ogg
  24          * packets, or until the callback returns a non-positive value. If it
  25          * returns negative, the audio file was not recognized by the audio
  26          * format handler. If it returns zero, the audio file is considered
  27          * valid, and no further processing by the callback is needed. In this
  28          * case the header chunk, i.e. chunk number zero, is defined as the
  29          * concatenation of all packets that have been processed by the
  30          * callback.
  31          */
  32         int (*packet_callback)(ogg_packet *packet, int packet_num,
  33                 int serial, struct afh_info *afhi, void *private_data);
  34         /** Data specific to the audio format handler. */
  35         void *private_data;
  36 };
  37
  38 int oac_get_file_info(char *map, size_t numbytes, struct afh_info *afhi,
  39                 struct oac_callback_info *ci);
  40 int oac_rewrite_tags(const char *map, size_t mapsize, int fd,
  41                 char *meta_packet, size_t meta_sz);