libkate: decoding.c

# decoding.c

    /*
      This shows the steps necessary to encode a Kate stream.
      For clarity, error checking is omitted.
      For simplicity, the input is assumed to be a single Kate stream.
      Usually, Kate streams will be multiplexed with other streams (either
      other Kate streams, or audio, or video). In these cases, the Ogg
      part will have to be more complex, but the Kate specific code will
      be the same.
      */

    #include <stdio.h>
    #include <string.h>
    #include "common.h"

    /* All the libkate API is available from the main kate header file: */

    #include <kate/oggkate.h>

    int main()
    {
      ogg_sync_state oy;
      ogg_stream_state os;
      int init=0;
      ogg_packet op;
      kate_state k;
      kate_info ki;
      kate_comment kc;
      const kate_event *ev;

      /* for the benefit of windows, which mangles data otherwise */
      set_binary_file(stdin);

      /* we initialize ogg and kate info/comment structures */
      ogg_sync_init(&oy);
      kate_info_init(&ki);
      kate_comment_init(&kc);

      /*
        First, read the headers, which must appear first in a Kate stream. When
        kate_decode_header returns a positive number, all headers have been seen
        and we're ready to decode data.
        */
      do {
        get_packet(&oy,&os,&init,&op);
      } while (kate_ogg_decode_headerin(&ki,&kc,&op)==0);

      /*
        We now have all the information we need from the headers, so we can
        initialize kate for decoding
        */
      kate_decode_init(&k,&ki);

      /*
        We can now read data, until kate_decode_packetin returns a positive
        number, signaling the end of the stream
        */
      while (1) {
        if (get_packet(&oy,&os,&init,&op)) break;
        if (kate_ogg_decode_packetin(&k,&op)>0) break;

        /* we may have an event (eg, text) */
        if (kate_decode_eventout(&k,&ev)==0) {
          printf("Kate stream has text: %s\n",ev->text);
        }
      }

      /* That's it, we can now cleanup */
      ogg_stream_clear(&os);
      ogg_sync_clear(&oy);

      kate_clear(&k);
      kate_info_clear(&ki);
      kate_comment_clear(&kc);

      return 0;
    }