paulo@0: /*
paulo@0: 
paulo@0: ljvorbis.c
paulo@0: Simple wrapper around vorbisfile for use with the Allegro library
paulo@0: copyright 2006 Damian Yerrick
paulo@0: based on vorbisfile example
paulo@0: copyright 1994-2004 Xiph.Org Foundation
paulo@0: licensed under a BSD style license set forth in COPYING-OGG.txt
paulo@0: 
paulo@0: */
paulo@0: 
paulo@0: #define ALLEGRO_USE_CONSOLE
paulo@0: #include <stdio.h>
paulo@0: #include "ljvorbis.h"
paulo@0: 
paulo@0: #define VORBIS_BYTEDEPTH 2  // number of bytes per sample; 2 means 16-bit
paulo@0: #define VORBIS_ENDIAN 0  // 0: x86/little; 2: ppc/big
paulo@0: #define VORBIS_SIGNED 0  // 0: unsigned; 1: signed; Allegro uses unsigned
paulo@0: 
paulo@0: LJVorbis *LJVorbis_open(const char *filename) {
paulo@0:   LJVorbis *ogg = malloc(sizeof(LJVorbis));
paulo@0:   if (!ogg) {
paulo@0:     return NULL;
paulo@0:   }
paulo@0:   ogg->fp = fopen(filename, "rb");
paulo@0:   if (!ogg->fp) {
paulo@0:     free(ogg);
paulo@0:     return NULL;
paulo@0:   }
paulo@0:   if (ov_open(ogg->fp, &(ogg->vf), NULL, 0) < 0) {
paulo@0:     fclose(ogg->fp);
paulo@0:     free(ogg);
paulo@0:     return NULL;
paulo@0:   }
paulo@0:   vorbis_info *vi=ov_info(&(ogg->vf),-1);
paulo@0:   ogg->rate = vi->rate;
paulo@0:   ogg->channels = vi->channels;
paulo@0:   ogg->length = ov_pcm_total(&(ogg->vf),-1);
paulo@0:   ogg->loopPoint = 0;
paulo@0:   ogg->voice = NULL;
paulo@0:   ogg->paused = 0;
paulo@0:   return ogg;
paulo@0: }
paulo@0: 
paulo@0: void LJVorbis_setLoop(LJVorbis *ogg, unsigned long int loopPoint) {
paulo@0:   if (ogg) {
paulo@0:     if (loopPoint < ogg->length) {
paulo@0:       ogg->loopPoint = loopPoint;
paulo@0:     } else {
paulo@0:       ogg->loopPoint = 0;
paulo@0:     }
paulo@0:   }
paulo@0: }
paulo@0: 
paulo@0: int LJVorbis_start(LJVorbis *ogg, int bufferSize, int vol, int pan) {
paulo@0:   if (ogg) {
paulo@0:   
paulo@0:     // if restarting, stop first
paulo@0:     if (ogg->voice) {
paulo@0:       LJVorbis_stop(ogg);
paulo@0:     }
paulo@0:     ogg->voice = play_audio_stream(bufferSize,
paulo@0:                                    8 * VORBIS_BYTEDEPTH,
paulo@0:                                    ogg->channels > 1,
paulo@0:                                    ogg->rate,
paulo@0:                                    vol, pan);
paulo@0:     ogg->bufferSize = bufferSize;
paulo@0:     if (!ogg->voice) {
paulo@0:       return -1;
paulo@0:     }
paulo@0:     ov_pcm_seek(&(ogg->vf), 0);
paulo@0:     return 0;
paulo@0:   }
paulo@0:   return -1;
paulo@0: }
paulo@0: 
paulo@0: void LJVorbis_stop(LJVorbis *ogg) {
paulo@0:   if (ogg && ogg->voice) {
paulo@0:     stop_audio_stream(ogg->voice);
paulo@0:     ogg->voice = NULL;
paulo@0:   }
paulo@0: }
paulo@0: 
paulo@0: void LJVorbis_close(LJVorbis *ogg) {
paulo@0:   if (ogg) {
paulo@0:     LJVorbis_stop(ogg);
paulo@0:     ov_clear(&(ogg->vf));  // finalize decoder and close the file
paulo@0:     // thanks kesiev for reminding me that ov_clear closes the file itself
paulo@0:     free(ogg);
paulo@0:   }
paulo@0: }
paulo@0: 
paulo@0: void LJVorbis_pause(LJVorbis *ogg, int value) {
paulo@0:   if (ogg && ogg->voice) {
paulo@0:     int hwVoice = ogg->voice->voice;
paulo@0:     voice_set_frequency(hwVoice, value ? 0 : ogg->rate);
paulo@0:     ogg->paused = value ? 1 : 0;
paulo@0:   }
paulo@0: }
paulo@0: 
paulo@0: int LJVorbis_poll(LJVorbis *ogg) {
paulo@0:   if (!ogg || !ogg->voice) {
paulo@0:     return -1;
paulo@0:   }
paulo@0:   char *buf = get_audio_stream_buffer(ogg->voice);
paulo@0:   int eofReached = 0;
paulo@0:     
paulo@0:   if (buf) {
paulo@0:     // the number of bytes left in this buffer
paulo@0:     long int bytesLeft = ogg->bufferSize * VORBIS_BYTEDEPTH * ogg->channels;
paulo@0: 
paulo@0:     while (bytesLeft > 0) {
paulo@0:       long ret=ov_read(&(ogg->vf),
paulo@0:                        buf,
paulo@0:                        bytesLeft,
paulo@0:                        VORBIS_ENDIAN,
paulo@0:                        VORBIS_BYTEDEPTH,
paulo@0:                        VORBIS_SIGNED,
paulo@0:                        &(ogg->bitstream));
paulo@0:       if (ret == 0) {
paulo@0:         // try to seek back to the beginning of the file
paulo@0:         int pcmErr = ov_pcm_seek(&(ogg->vf), ogg->loopPoint);
paulo@0:         if (pcmErr) {
paulo@0:           /* EOF */
paulo@0:           eofReached = 1;
paulo@0:           bytesLeft = 0;
paulo@0:         }
paulo@0:       } else if (ret < 0) {
paulo@0:         // Stream error. Just ignore it.
paulo@0:       } else {
paulo@0:         /* FIXME: handle sample rate changes, etc */
paulo@0:         // advance forward in the buffer
paulo@0:         buf += ret;
paulo@0:         bytesLeft -= ret;
paulo@0:       }
paulo@0:     }
paulo@0:     free_audio_stream_buffer(ogg->voice);
paulo@0:   }
paulo@0:   return eofReached;
paulo@0: }
paulo@0: 
paulo@0: #ifdef LJVORBIS_DEMO
paulo@0: int main(){
paulo@0:   int eofReached = 0;
paulo@0:   LJVorbis *ogg = LJVorbis_open("AM-3P.ogg");
paulo@0: 
paulo@0:   if (!ogg) {
paulo@0:     fprintf(stderr, "Could not open AM-3P.ogg.\n");
paulo@0:     exit(1);
paulo@0:   }
paulo@0:   LJVorbis_setLoop(ogg, 650772);
paulo@0: 
paulo@0:   if (allegro_init() < 0
paulo@0:       || install_timer() < 0
paulo@0:       || set_gfx_mode(GFX_SAFE, 320, 200, 0, 0) < 0
paulo@0:       || install_keyboard() < 0
paulo@0:       || install_sound(DIGI_AUTODETECT, MIDI_NONE, NULL) < 0) {
paulo@0:     allegro_exit();
paulo@0:     LJVorbis_close(ogg);
paulo@0:     fprintf(stderr, "Could not start Allegro library: %s\n", allegro_error);
paulo@0:     exit(1);
paulo@0:   }
paulo@0: 
paulo@0:   /* Throw the comments plus a few lines about the bitstream we're
paulo@0:      decoding */
paulo@0:   if (0)
paulo@0:   {
paulo@0:     char line1[80], line2[80];
paulo@0:     
paulo@0:     usprintf(line1,"%d channels, %u Hz", ogg->channels, ogg->rate);
paulo@0:     usprintf(line2,"length: %lu samples", ogg->length);
paulo@0:     alert(line1, line2, "ready?",
paulo@0:           "Play", 0, 13, 0);
paulo@0:   }
paulo@0:   
paulo@0:   if (LJVorbis_start(ogg, 1024, 192, 128) < 0) {
paulo@0:     LJVorbis_close(ogg);
paulo@0:     alert("Could not allocate voice",
paulo@0:           "for playing audio.",
paulo@0:           "",
paulo@0:           "OK", 0, 13, 0);
paulo@0:     exit(1);
paulo@0:   }
paulo@0:   
paulo@0:   while(!eofReached){
paulo@0:     eofReached = LJVorbis_poll(ogg);
paulo@0:     rest(16);
paulo@0:     
paulo@0:     if (keypressed()) {
paulo@0:       int scancode;
paulo@0:       ureadkey(&scancode);
paulo@0:       
paulo@0:       if (scancode == KEY_P) {
paulo@0:         LJVorbis_pause(ogg, !ogg->paused);
paulo@0:       } else if (scancode == KEY_ESC) {
paulo@0:         eofReached = 1;
paulo@0:       }
paulo@0:     }
paulo@0:   }
paulo@0: 
paulo@0:   /* cleanup */
paulo@0:   LJVorbis_close(ogg);
paulo@0:   return(0);
paulo@0: }
paulo@0: END_OF_MAIN();
paulo@0: #endif