rockbox/apps/codecs/vgm.c
2011-08-13 16:41:14 +00:00

142 lines
4 KiB
C

/* Ripped off from Game_Music_Emu 0.5.2. http://www.slack.net/~ant/ */
/* Inflate code taken from WikiViewer plugin by Adam Gashlin */
#include <codecs/lib/codeclib.h>
#include "libgme/blargg_endian.h"
#include "libgme/vgm_emu.h"
#include "libgme/inflate/mallocer.h"
#include "libgme/inflate/inflate.h"
CODEC_HEADER
/* Maximum number of bytes to process in one iteration */
#define CHUNK_SIZE (1024*4)
#define MAINMEMBUF 0
static int16_t samples[CHUNK_SIZE] IBSS_ATTR;
static struct Vgm_Emu vgm_emu;
static void *inflatebuf; /* heap for gunzip */
static char *songbuf; /* destination for uncompressed song */
static uint32_t songbuflen=0; /* size of the song buffer */
static uint32_t songlen=0; /* used size of the song buffer */
/****************** rockbox interface ******************/
/* this is the codec entry point */
enum codec_status codec_main(enum codec_entry_call_reason reason)
{
if (reason == CODEC_LOAD) {
/* we only render 16 bits */
ci->configure(DSP_SET_SAMPLE_DEPTH, 16);
/* 32 Khz, Interleaved stereo */
ci->configure(DSP_SET_FREQUENCY, 44100);
ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
Vgm_init(&vgm_emu);
Vgm_set_sample_rate(&vgm_emu, 44100);
}
return CODEC_OK;
}
/* this is called for each file to process */
enum codec_status codec_run(void)
{
blargg_err_t err;
uint8_t *buf;
size_t n;
intptr_t param;
uint32_t elapsed_time = 0;
DEBUGF("VGM: next_track\n");
if (codec_init()) {
return CODEC_ERROR;
}
codec_set_replaygain(ci->id3);
/* Read the entire file */
DEBUGF("VGM: request file\n");
ci->seek_buffer(0);
buf = ci->request_buffer(&n, ci->filesize);
if (!buf) {
DEBUGF("VGM: file load failed\n");
return CODEC_ERROR;
}
/* If couldn't get the whole buffer
will trim file and put and 'end_command'
at the end*/
if (n < (size_t)ci->filesize) {
DEBUGF("VGM: file was trimmed\n");
}
/* If is gzipped decompress it */
if ( get_le16( buf ) == 0x8b1f ) {
wpw_init_mempool(MAINMEMBUF);
inflatebuf=wpw_malloc(MAINMEMBUF,0x13500);
/* Will use available remaining memory
as output buffer */
songbuflen=wpw_available(MAINMEMBUF);
songbuf=wpw_malloc(MAINMEMBUF,songbuflen);
songlen=decompress(buf,n,songbuf,songbuflen,0,inflatebuf);
if ((err = Vgm_load_mem(&vgm_emu, songbuf, songlen, true))) {
DEBUGF("VGM: Vgm_load_mem failed (%s)\n", err);
return CODEC_ERROR;
}
/* Since metadata parser doesn't support VGZ
will set song length here */
ci->id3->length = Track_get_length( &vgm_emu );
}
else if ((err = Vgm_load_mem(&vgm_emu, buf, n, false))) {
DEBUGF("VGM: Vgm_load failed_mem (%s)\n", err);
return CODEC_ERROR;
}
Vgm_start_track(&vgm_emu);
/* for REPEAT_ONE we disable track limits */
if (ci->global_settings->repeat_mode != REPEAT_ONE) {
Track_set_fade(&vgm_emu, ci->id3->length - 4000, 4000);
}
ci->set_elapsed(0);
/* The main decoder loop */
while (1) {
enum codec_command_action action = ci->get_command(&param);
if (action == CODEC_ACTION_HALT)
break;
if (action == CODEC_ACTION_SEEK_TIME) {
ci->set_elapsed(param);
elapsed_time = param;
Track_seek(&vgm_emu, param);
ci->seek_complete();
/* Set fade again in case we seek to start of song */
Track_set_fade(&vgm_emu, ci->id3->length - 4000, 4000);
}
/* Generate audio buffer */
err = Vgm_play(&vgm_emu, CHUNK_SIZE, samples);
if (err || vgm_emu.track_ended) break;
ci->pcmbuf_insert(samples, NULL, CHUNK_SIZE >> 1);
elapsed_time += (CHUNK_SIZE / 2) / 44.1;
ci->set_elapsed(elapsed_time);
}
return CODEC_OK;
}