apps/codecs/nsf.c

   1
   2 /* Ripped off from Game_Music_Emu 0.5.2. http://www.slack.net/~ant/ */
   3
   4 #define GME_NSF_TYPE
   5
   6 #include <codecs/lib/codeclib.h>
   7 #include "libgme/nsf_emu.h"
   8
   9 CODEC_HEADER
  10
  11 /* Maximum number of bytes to process in one iteration */
  12 #define CHUNK_SIZE (1024*2)
  13
  14 static int16_t samples[CHUNK_SIZE] IBSS_ATTR;
  15 static struct Nsf_Emu nsf_emu;
  16
  17 /****************** rockbox interface ******************/
  18
  19 static void set_codec_track(int t, int multitrack) {
  20     Nsf_start_track(&nsf_emu, t);
  21
  22     /* for REPEAT_ONE we disable track limits */
  23     if (ci->global_settings->repeat_mode != REPEAT_ONE) {
  24         Track_set_fade(&nsf_emu, Track_length( &nsf_emu, t ) - 4000, 4000);
  25     }
  26     if (multitrack) ci->set_elapsed(t*1000); /* t is track no to display */
  27     else ci->set_elapsed(0);
  28 }
  29
  30 /* this is the codec entry point */
  31 enum codec_status codec_main(enum codec_entry_call_reason reason)
  32 {
  33     if (reason == CODEC_LOAD) {
  34         /* we only render 16 bits */
  35         ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
  36
  37         /* 44 Khz, Interleaved stereo */
  38         ci->configure(DSP_SET_FREQUENCY, 44100);
  39         ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
  40
  41         Nsf_init(&nsf_emu);
  42         Nsf_set_sample_rate(&nsf_emu, 44100);
  43     }
  44
  45     return CODEC_OK;
  46 }
  47
  48 /* this is called for each file to process */
  49 enum codec_status codec_run(void)
  50 {
  51     blargg_err_t err;
  52     uint8_t *buf;
  53     size_t n;
  54     int track, is_multitrack;
  55     uint32_t elapsed_time;
  56     intptr_t param;
  57
  58     track = is_multitrack = 0;
  59     elapsed_time = 0;
  60
  61     DEBUGF("NSF: next_track\n");
  62     if (codec_init()) {
  63         return CODEC_ERROR;
  64     }
  65
  66     codec_set_replaygain(ci->id3);
  67
  68     /* Read the entire file */
  69     DEBUGF("NSF: request file\n");
  70     ci->seek_buffer(0);
  71     buf = ci->request_buffer(&n, ci->filesize);
  72     if (!buf || n < (size_t)ci->filesize) {
  73         DEBUGF("NSF: file load failed\n");
  74         return CODEC_ERROR;
  75     }
  76
  77     if ((err = Nsf_load(&nsf_emu, buf, ci->filesize))) {
  78         DEBUGF("NSF: Nsf_load failed (%s)\n", err);
  79         return CODEC_ERROR;
  80     }
  81
  82     /* Update internal track count */
  83     if (nsf_emu.m3u.size > 0)
  84         nsf_emu.track_count = nsf_emu.m3u.size;
  85
  86     if (nsf_emu.track_count > 1) is_multitrack = 1;
  87
  88 next_track:
  89     set_codec_track(track, is_multitrack);
  90
  91     /* The main decoder loop */
  92     while (1) {
  93         enum codec_command_action action = ci->get_command(&param);
  94
  95         if (action == CODEC_ACTION_HALT)
  96             break;
  97
  98         if (action == CODEC_ACTION_SEEK_TIME) {
  99             if (is_multitrack) {
 100                 track = param/1000;
 101                 ci->seek_complete();
 102                 if (track >= nsf_emu.track_count) break;
 103                 goto next_track;
 104             }
 105
 106             ci->set_elapsed(param);
 107             elapsed_time = param;
 108             Track_seek(&nsf_emu, param);
 109             ci->seek_complete();
 110
 111             /* Set fade again */
 112             if (ci->global_settings->repeat_mode != REPEAT_ONE) {
 113                 Track_set_fade(&nsf_emu, Track_length( &nsf_emu, track ), 4000);
 114             }
 115         }
 116
 117         /* Generate audio buffer */
 118         err = Nsf_play(&nsf_emu, CHUNK_SIZE, samples);
 119         if (err || nsf_emu.track_ended) {
 120             track++;
 121             if (track >= nsf_emu.track_count) break;
 122             goto next_track;
 123         }
 124
 125         ci->pcmbuf_insert(samples, NULL, CHUNK_SIZE >> 1);
 126
 127         /* Set elapsed time for one track files */
 128         if (is_multitrack == 0) {
 129             elapsed_time += (CHUNK_SIZE / 2) / 44.1;
 130             ci->set_elapsed(elapsed_time);
 131         }
 132     }
 133
 134     return CODEC_OK;
 135 }