apps/codecs/vgm.c

   1
   2 /* Ripped off from Game_Music_Emu 0.5.2. http://www.slack.net/~ant/ */
   3 /* Inflate code taken from WikiViewer plugin by Adam Gashlin */
   4
   5 #include <codecs/lib/codeclib.h>
   6
   7 #include "libgme/blargg_endian.h"
   8 #include "libgme/vgm_emu.h"
   9 #include "libgme/inflate/mallocer.h"
  10 #include "libgme/inflate/inflate.h"
  11
  12 CODEC_HEADER
  13
  14 /* Maximum number of bytes to process in one iteration */
  15 #define CHUNK_SIZE (1024*4)
  16 #define MAINMEMBUF 0
  17
  18 static int16_t samples[CHUNK_SIZE] IBSS_ATTR;
  19 static struct Vgm_Emu vgm_emu;
  20
  21 static void *inflatebuf;              /* heap for gunzip */
  22 static char *songbuf;               /* destination for uncompressed song */
  23 static uint32_t songbuflen=0;  /* size of the song buffer */
  24 static uint32_t songlen=0;       /* used size of the song buffer */
  25
  26 /****************** rockbox interface ******************/
  27
  28 /* this is the codec entry point */
  29 enum codec_status codec_main(enum codec_entry_call_reason reason)
  30 {
  31     if (reason == CODEC_LOAD) {
  32         /* we only render 16 bits */
  33         ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
  34
  35         /* 32 Khz, Interleaved stereo */
  36         ci->configure(DSP_SET_FREQUENCY, 44100);
  37         ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
  38
  39         Vgm_init(&vgm_emu);
  40         Vgm_set_sample_rate(&vgm_emu, 44100);
  41     }
  42
  43     return CODEC_OK;
  44 }
  45
  46 /* this is called for each file to process */
  47 enum codec_status codec_run(void)
  48 {
  49     blargg_err_t err;
  50     uint8_t *buf;
  51     size_t n;
  52     intptr_t param;
  53
  54     uint32_t elapsed_time = 0;
  55
  56     DEBUGF("VGM: next_track\n");
  57     if (codec_init()) {
  58         return CODEC_ERROR;
  59     }
  60
  61     codec_set_replaygain(ci->id3);
  62
  63     /* Read the entire file */
  64     DEBUGF("VGM: request file\n");
  65     ci->seek_buffer(0);
  66     buf = ci->request_buffer(&n, ci->filesize);
  67     if (!buf) {
  68         DEBUGF("VGM: file load failed\n");
  69         return CODEC_ERROR;
  70     }
  71
  72     /* If couldn't get the whole buffer
  73         will trim file and put and 'end_command'
  74         at the end*/
  75     if (n < (size_t)ci->filesize) {
  76         DEBUGF("VGM: file was trimmed\n");
  77     }
  78
  79     /* If is gzipped decompress it */
  80     if ( get_le16( buf ) == 0x8b1f ) {
  81         wpw_init_mempool(MAINMEMBUF);
  82         inflatebuf=wpw_malloc(MAINMEMBUF,0x13500);
  83
  84         /* Will use available remaining memory
  85             as output buffer */
  86         songbuflen=wpw_available(MAINMEMBUF);
  87         songbuf=wpw_malloc(MAINMEMBUF,songbuflen);
  88
  89         songlen=decompress(buf,n,songbuf,songbuflen,0,inflatebuf);
  90
  91         if ((err = Vgm_load_mem(&vgm_emu, songbuf, songlen, true))) {
  92             DEBUGF("VGM: Vgm_load_mem failed (%s)\n", err);
  93             return CODEC_ERROR;
  94         }
  95
  96         /* Since metadata parser doesn't support VGZ
  97              will set song length here */
  98         ci->id3->length = Track_get_length( &vgm_emu );
  99     }
 100     else if ((err = Vgm_load_mem(&vgm_emu, buf, n, false))) {
 101         DEBUGF("VGM: Vgm_load failed_mem (%s)\n", err);
 102         return CODEC_ERROR;
 103     }
 104
 105     Vgm_start_track(&vgm_emu);
 106
 107     /* for REPEAT_ONE we disable track limits */
 108     if (ci->global_settings->repeat_mode != REPEAT_ONE) {
 109         Track_set_fade(&vgm_emu, ci->id3->length - 4000, 4000);
 110     }
 111
 112     ci->set_elapsed(0);
 113
 114     /* The main decoder loop */
 115     while (1) {
 116         enum codec_command_action action = ci->get_command(&param);
 117
 118         if (action == CODEC_ACTION_HALT)
 119             break;
 120
 121         if (action == CODEC_ACTION_SEEK_TIME) {
 122             ci->set_elapsed(param);
 123             elapsed_time = param;
 124             Track_seek(&vgm_emu, param);
 125             ci->seek_complete();
 126
 127             /* Set fade again in case we seek to start of song */
 128             Track_set_fade(&vgm_emu, ci->id3->length - 4000, 4000);
 129         }
 130
 131         /* Generate audio buffer */
 132         err = Vgm_play(&vgm_emu, CHUNK_SIZE, samples);
 133         if (err || vgm_emu.track_ended) break;
 134
 135         ci->pcmbuf_insert(samples, NULL, CHUNK_SIZE >> 1);
 136
 137         elapsed_time += (CHUNK_SIZE / 2) / 44.1;
 138         ci->set_elapsed(elapsed_time);
 139     }
 140
 141     return CODEC_OK;
 142 }