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/* Ripped off from Game_Music_Emu 0.5.2. http://www.slack.net/~ant/ */
#include <codecs/lib/codeclib.h>
#include "libgme/ay_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 Ay_Emu ay_emu;
/****************** rockbox interface ******************/
static void set_codec_track(int t, int multitrack) {
Ay_start_track(&ay_emu, t);
/* for loop mode we disable track limits */
if (!ci->loop_track()) {
Track_set_fade(&ay_emu, Track_get_length( &ay_emu, t ) - 4000, 4000);
}
if (multitrack) ci->set_elapsed(t*1000); /* t is track no to display */
else ci->set_elapsed(0);
}
/* 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);
Ay_init(&ay_emu);
Ay_set_sample_rate(&ay_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;
int track, is_multitrack;
intptr_t param;
uint32_t elapsed_time;
/* reset values */
track = is_multitrack = 0;
elapsed_time = 0;
param = ci->id3->elapsed;
DEBUGF("AY: next_track\n");
if (codec_init()) {
return CODEC_ERROR;
}
codec_set_replaygain(ci->id3);
/* Read the entire file */
DEBUGF("AY: request file\n");
ci->seek_buffer(0);
buf = ci->request_buffer(&n, ci->filesize);
if (!buf || n < (size_t)ci->filesize) {
DEBUGF("AY: file load failed\n");
return CODEC_ERROR;
}
if ((err = Ay_load_mem(&ay_emu, buf, ci->filesize))) {
DEBUGF("AY: Ay_load_mem failed (%s)\n", err);
return CODEC_ERROR;
}
/* Update internal track count */
if (ay_emu.m3u.size > 0)
ay_emu.track_count = ay_emu.m3u.size;
/* Check if file has multiple tracks */
if (ay_emu.track_count > 1) {
is_multitrack = 1;
}
if (param) {
goto resume_start;
}
next_track:
set_codec_track(track, is_multitrack);
/* The main decoder loop */
while (1) {
long action = ci->get_command(¶m);
if (action == CODEC_ACTION_HALT)
break;
if (action == CODEC_ACTION_SEEK_TIME) {
resume_start:
if (is_multitrack) {
track = param/1000;
ci->seek_complete();
if (track >= ay_emu.track_count) break;
goto next_track;
}
ci->set_elapsed(param);
elapsed_time = param;
Track_seek(&ay_emu, param);
ci->seek_complete();
/* Set fade again */
if (!ci->loop_track()) {
Track_set_fade(&ay_emu, Track_get_length( &ay_emu, track ) - 4000, 4000);
}
}
/* Generate audio buffer */
err = Ay_play(&ay_emu, CHUNK_SIZE, samples);
if (err || Track_ended(&ay_emu)) {
track++;
if (track >= ay_emu.track_count) break;
goto next_track;
}
ci->pcmbuf_insert(samples, NULL, CHUNK_SIZE >> 1);
/* Set elapsed time for one track files */
if (!is_multitrack) {
elapsed_time += (CHUNK_SIZE / 2) * 10 / 441;
ci->set_elapsed(elapsed_time);
}
}
return CODEC_OK;
}
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