--- /dev/null
+// Some mp3 related code for Sega/Mega CD.
+// Uses the Helix Fixed-point MP3 decoder
+
+// (c) Copyright 2007, Grazvydas "notaz" Ignotas
+
+#include <stdio.h>
+#include <string.h>
+
+#include "../../Pico/PicoInt.h"
+#include "../../Pico/sound/mix.h"
+#include "helix/pub/mp3dec.h"
+#include "lprintf.h"
+
+static short mp3_out_buffer[2*1152];
+static HMP3Decoder mp3dec = 0;
+static int mp3_buffer_offs = 0;
+
+
+static int try_get_header(unsigned char *buff, MP3FrameInfo *fi)
+{
+ int ret, offs1, offs = 0;
+
+ while (1)
+ {
+ offs1 = MP3FindSyncWord(buff + offs, 2048 - offs);
+ if (offs1 < 0) return -2;
+ offs += offs1;
+ if (2048 - offs < 4) return -3;
+
+ // printf("trying header %08x\n", *(int *)(buff + offs));
+
+ ret = MP3GetNextFrameInfo(mp3dec, fi, buff + offs);
+ if (ret == 0 && fi->bitrate != 0) break;
+ offs++;
+ }
+
+ return ret;
+}
+
+int mp3_get_bitrate(FILE *f, int len)
+{
+ unsigned char buff[2048];
+ MP3FrameInfo fi;
+ int ret;
+
+ memset(buff, 0, 2048);
+
+ if (!mp3dec) mp3dec = MP3InitDecoder();
+
+ fseek(f, 0, SEEK_SET);
+ ret = fread(buff, 1, 2048, f);
+ fseek(f, 0, SEEK_SET);
+ if (ret <= 0) return -1;
+
+ ret = try_get_header(buff, &fi);
+ if (ret != 0 || fi.bitrate == 0) {
+ // try to read somewhere around the middle
+ fseek(f, len>>1, SEEK_SET);
+ fread(buff, 1, 2048, f);
+ fseek(f, 0, SEEK_SET);
+ ret = try_get_header(buff, &fi);
+ }
+ if (ret != 0) return ret;
+
+ // printf("bitrate: %i\n", fi.bitrate / 1000);
+
+ return fi.bitrate / 1000;
+}
+
+
+#ifdef __GP2X__
+
+#include "../gp2x/code940/940shared.h"
+
+extern _940_ctl_t *shared_ctl;
+extern unsigned char *mp3_mem;
+
+static int mp3_decode(void)
+{
+ // tried copying this to cached mem, no improvement noticed
+ int mp3_offs = shared_ctl->mp3_offs;
+ unsigned char *readPtr = mp3_mem + mp3_offs;
+ int bytesLeft = shared_ctl->mp3_len - mp3_offs;
+ int offset; // frame offset from readPtr
+ int err;
+
+ if (bytesLeft <= 0) return 1; // EOF, nothing to do
+
+ offset = MP3FindSyncWord(readPtr, bytesLeft);
+ if (offset < 0) {
+ shared_ctl->mp3_offs = shared_ctl->mp3_len;
+ return 1; // EOF
+ }
+ readPtr += offset;
+ bytesLeft -= offset;
+
+ err = MP3Decode(mp3dec, &readPtr, &bytesLeft, mp3_out_buffer, 0);
+ if (err) {
+ if (err == ERR_MP3_INDATA_UNDERFLOW) {
+ shared_ctl->mp3_offs = shared_ctl->mp3_len; // EOF
+ return 1;
+ } else if (err <= -6 && err >= -12) {
+ // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
+ // just try to skip the offending frame..
+ readPtr++;
+ }
+ shared_ctl->mp3_errors++;
+ shared_ctl->mp3_lasterr = err;
+ }
+ shared_ctl->mp3_offs = readPtr - mp3_mem;
+ return 0;
+}
+
+void mp3_start_local(void)
+{
+ mp3_buffer_offs = 0;
+ mp3_decode();
+}
+
+#define mp3_update mp3_update_local
+
+#else
+
+static FILE *mp3_current_file = NULL;
+static int mp3_file_len = 0, mp3_file_pos = 0;
+static unsigned char mp3_input_buffer[2*1024];
+
+static int mp3_decode(void)
+{
+ unsigned char *readPtr;
+ int bytesLeft;
+ int offset; // mp3 frame offset from readPtr
+ int err;
+
+ do
+ {
+ if (mp3_file_pos >= mp3_file_len) return 1; // EOF, nothing to do
+
+ fseek(mp3_current_file, mp3_file_pos, SEEK_SET);
+ bytesLeft = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), mp3_current_file);
+
+ offset = MP3FindSyncWord(mp3_input_buffer, bytesLeft);
+ if (offset < 0) {
+ //lprintf("MP3FindSyncWord (%i/%i) err %i\n", mp3_file_pos, mp3_file_len, offset);
+ mp3_file_pos = mp3_file_len;
+ return 1; // EOF
+ }
+ readPtr = mp3_input_buffer + offset;
+ bytesLeft -= offset;
+
+ err = MP3Decode(mp3dec, &readPtr, &bytesLeft, mp3_out_buffer, 0);
+ if (err) {
+ //lprintf("MP3Decode err (%i/%i) %i\n", mp3_file_pos, mp3_file_len, err);
+ if (err == ERR_MP3_INDATA_UNDERFLOW) {
+ if (offset == 0)
+ // something's really wrong here, frame had to fit
+ mp3_file_pos = mp3_file_len;
+ else
+ mp3_file_pos += offset;
+ continue;
+ } else if (err <= -6 && err >= -12) {
+ // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
+ // just try to skip the offending frame..
+ mp3_file_pos += offset + 1;
+ continue;
+ }
+ mp3_file_pos = mp3_file_len;
+ return 1;
+ }
+ mp3_file_pos += readPtr - mp3_input_buffer;
+ }
+ while (0);
+
+ return 0;
+}
+
+void mp3_start_play(FILE *f, int pos)
+{
+ mp3_file_len = mp3_file_pos = 0;
+ mp3_current_file = NULL;
+ mp3_buffer_offs = 0;
+
+ if (!(PicoOpt&0x800) || f == NULL) // cdda disabled or no file?
+ return;
+
+ //lprintf("mp3_start_play %p %i\n", f, pos);
+
+ mp3_current_file = f;
+ fseek(f, 0, SEEK_END);
+ mp3_file_len = ftell(f);
+
+ // seek..
+ if (pos) {
+ mp3_file_pos = (mp3_file_len << 6) >> 10;
+ mp3_file_pos *= pos;
+ mp3_file_pos >>= 6;
+ }
+
+ mp3_decode();
+}
+
+int mp3_get_offset(void)
+{
+ unsigned int offs1024 = 0;
+ int cdda_on;
+
+ cdda_on = (PicoMCD & 1) && (PicoOpt&0x800) && !(Pico_mcd->s68k_regs[0x36] & 1) &&
+ (Pico_mcd->scd.Status_CDC & 1) && mp3_current_file != NULL;
+
+ if (cdda_on) {
+ offs1024 = mp3_file_pos << 7;
+ offs1024 /= mp3_file_len >> 3;
+ }
+ //lprintf("mp3_get_offset offs1024=%u (%i/%i)\n", offs1024, mp3_file_pos, mp3_file_len);
+
+ return offs1024;
+}
+
+#endif // ifndef __GP2X__
+
+void mp3_update(int *buffer, int length, int stereo)
+{
+ int length_mp3, shr = 0;
+ void (*mix_samples)(int *dest_buf, short *mp3_buf, int count) = mix_16h_to_32;
+
+#ifndef __GP2X__
+ if (mp3_current_file == NULL || mp3_file_pos >= mp3_file_len) return; // no file / EOF
+#endif
+
+ length_mp3 = length;
+ if (PsndRate == 22050) { mix_samples = mix_16h_to_32_s1; length_mp3 <<= 1; shr = 1; }
+ else if (PsndRate == 11025) { mix_samples = mix_16h_to_32_s2; length_mp3 <<= 2; shr = 2; }
+
+ if (1152 - mp3_buffer_offs >= length_mp3) {
+ mix_samples(buffer, mp3_out_buffer + mp3_buffer_offs*2, length<<1);
+
+ mp3_buffer_offs += length_mp3;
+ } else {
+ int ret, left = 1152 - mp3_buffer_offs;
+
+ mix_samples(buffer, mp3_out_buffer + mp3_buffer_offs*2, (left>>shr)<<1);
+ ret = mp3_decode();
+ if (ret == 0) {
+ mp3_buffer_offs = length_mp3 - left;
+ mix_samples(buffer + ((left>>shr)<<1), mp3_out_buffer, (mp3_buffer_offs>>shr)<<1);
+ } else
+ mp3_buffer_offs = 0;
+ }
+}
+
+
notaz.gp2x.de / libpicofe.git / blobdiff