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

108 lines
2.7 KiB
C

/* Ripped off from Game_Music_Emu 0.5.2. http://www.slack.net/~ant/ */
#include <codecs/lib/codeclib.h>
#include "libgme/gbs_emu.h"
CODEC_HEADER
/* Maximum number of bytes to process in one iteration */
#define CHUNK_SIZE (1024*2)
static int16_t samples[CHUNK_SIZE] IBSS_ATTR;
static struct Gbs_Emu gbs_emu;
/****************** rockbox interface ******************/
static void set_codec_track(int t) {
Gbs_start_track(&gbs_emu, t);
/* for REPEAT_ONE we disable track limits */
if (ci->global_settings->repeat_mode != REPEAT_ONE) {
Track_set_fade(&gbs_emu, Track_get_length( &gbs_emu, t ), 4000);
}
ci->set_elapsed(t*1000); /* t is track no to display */
}
/* 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);
/* 44 Khz, Interleaved stereo */
ci->configure(DSP_SET_FREQUENCY, 44100);
ci->configure(DSP_SET_STEREO_MODE, STEREO_INTERLEAVED);
Gbs_init(&gbs_emu);
Gbs_set_sample_rate(&gbs_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;
int track = 0;
DEBUGF("GBS: next_track\n");
if (codec_init()) {
return CODEC_ERROR;
}
codec_set_replaygain(ci->id3);
/* Read the entire file */
DEBUGF("GBS: request file\n");
ci->seek_buffer(0);
buf = ci->request_buffer(&n, ci->filesize);
if (!buf || n < (size_t)ci->filesize) {
DEBUGF("GBS: file load failed\n");
return CODEC_ERROR;
}
if ((err = Gbs_load(&gbs_emu, buf, ci->filesize))) {
DEBUGF("GBS: Gbs_load failed (%s)\n", err);
return CODEC_ERROR;
}
/* Update internal track count */
if (gbs_emu.m3u.size > 0)
gbs_emu.track_count = gbs_emu.m3u.size;
next_track:
set_codec_track(track);
/* 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) {
track = param/1000;
ci->seek_complete();
if (track >= gbs_emu.track_count) break;
goto next_track;
}
/* Generate audio buffer */
err = Gbs_play(&gbs_emu, CHUNK_SIZE, samples);
if (err || gbs_emu.track_ended) {
track++;
if (track >= gbs_emu.track_count) break;
goto next_track;
}
ci->pcmbuf_insert(samples, NULL, CHUNK_SIZE >> 1);
}
return CODEC_OK;
}