apps/codecs/sgc.c

   1
   2 /* Ripped off from Game_Music_Emu 0.5.2. http://www.slack.net/~ant/ */
   3
   4 #include <codecs/lib/codeclib.h>
   5 #include "libgme/sgc_emu.h"
   6
   7 CODEC_HEADER
   8
   9 /* Maximum number of bytes to process in one iteration */
  10 #define CHUNK_SIZE (1024*2)
  11
  12 static int16_t samples[CHUNK_SIZE] IBSS_ATTR;
  13 static struct Sgc_Emu sgc_emu IDATA_ATTR CACHEALIGN_ATTR;
  14
  15 /* Coleco Bios */
  16 /* Colecovision not supported yet
  17 static char coleco_bios[0x2000];
  18 */
  19
  20 /****************** rockbox interface ******************/
  21
  22 static void set_codec_track(int t) {
  23     Sgc_start_track(&sgc_emu, t);
  24
  25     /* for REPEAT_ONE we disable track limits */
  26     if (ci->global_settings->repeat_mode != REPEAT_ONE) {
  27         Track_set_fade(&sgc_emu, Track_get_length( &sgc_emu, t ), 4000);
  28     }
  29     ci->set_elapsed(t*1000); /* t is track no to display */
  30 }
  31
  32 /* this is the codec entry point */
  33 enum codec_status codec_main(enum codec_entry_call_reason reason)
  34 {
  35     if (reason == CODEC_LOAD) {
  36         /* we only render 16 bits */
  37         ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
  38
  39         /* 44 Khz, Interleaved stereo */
  40         ci->configure(DSP_SET_FREQUENCY, 44100);
  41         ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
  42
  43         Sgc_init(&sgc_emu);
  44         Sgc_set_sample_rate(&sgc_emu, 44100);
  45
  46         /* set coleco bios, should be named coleco_bios.rom */
  47         /* Colecovision not supported yet
  48         int fd = ci->open("/coleco_bios.rom", O_RDONLY);
  49         if ( fd >= 0 ) {
  50             ci->read(fd, coleco_bios, 0x2000);
  51             ci->close(fd);
  52             set_coleco_bios( &sgc_emu, coleco_bios );
  53         }
  54         */
  55     }
  56
  57     return CODEC_OK;
  58 }
  59
  60 /* this is called for each file to process */
  61 enum codec_status codec_run(void)
  62 {
  63     blargg_err_t err;
  64     uint8_t *buf;
  65     size_t n;
  66     intptr_t param;
  67     int track = 0;
  68
  69     DEBUGF("SGC: next_track\n");
  70     if (codec_init()) {
  71         return CODEC_ERROR;
  72     }
  73
  74     codec_set_replaygain(ci->id3);
  75
  76     /* Read the entire file */
  77     DEBUGF("SGC: request file\n");
  78     ci->seek_buffer(0);
  79     buf = ci->request_buffer(&n, ci->filesize);
  80     if (!buf || n < (size_t)ci->filesize) {
  81         DEBUGF("SGC: file load failed\n");
  82         return CODEC_ERROR;
  83     }
  84
  85     if ((err = Sgc_load_mem(&sgc_emu, buf, ci->filesize))) {
  86         DEBUGF("SGC: Sgc_load failed (%s)\n", err);
  87         return CODEC_ERROR;
  88     }
  89
  90     /* Update internal track count */
  91     if (sgc_emu.m3u.size > 0)
  92         sgc_emu.track_count = sgc_emu.m3u.size;
  93
  94 next_track:
  95     set_codec_track(track);
  96
  97     /* The main decoder loop */
  98     while (1) {
  99         enum codec_command_action action = ci->get_command(&param);
 100
 101         if (action == CODEC_ACTION_HALT)
 102             break;
 103
 104         if (action == CODEC_ACTION_SEEK_TIME) {
 105             track = param/1000;
 106             ci->seek_complete();
 107             if (track >= sgc_emu.track_count) break;
 108             goto next_track;
 109         }
 110
 111         /* Generate audio buffer */
 112         err = Sgc_play(&sgc_emu, CHUNK_SIZE, samples);
 113         if (err || sgc_emu.track_ended) {
 114             track++;
 115             if (track >= sgc_emu.track_count) break;
 116             goto next_track;
 117         }
 118
 119         ci->pcmbuf_insert(samples, NULL, CHUNK_SIZE >> 1);
 120     }
 121
 122     return CODEC_OK;
 123 }