+++ /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/pico_int.h>
-#include <pico/sound/mix.h>
-#include "helix/pub/mp3dec.h"
-#include "mp3.h"
-#include "lprintf.h"
-
-static HMP3Decoder mp3dec = 0;
-static FILE *mp3_current_file = NULL;
-static int mp3_file_len = 0, mp3_file_pos = 0;
-static int mp3_buffer_offs = 0;
-static unsigned char mp3_input_buffer[2*1024];
-
-#ifdef __GP2X__
-#define mp3_update mp3_update_local
-#define mp3_start_play mp3_start_play_local
-#endif
-
-static int try_get_header(unsigned char *buff, MP3FrameInfo *fi)
-{
- int ret, offs1, offs = 0;
-
- while (1)
- {
- offs1 = mp3_find_sync_word(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(void *f_, int len)
-{
- unsigned char buff[2048];
- MP3FrameInfo fi;
- FILE *f = f_;
- int ret;
-
- memset(buff, 0, sizeof(buff));
-
- if (mp3dec)
- MP3FreeDecoder(mp3dec);
- mp3dec = MP3InitDecoder();
-
- fseek(f, 0, SEEK_SET);
- ret = fread(buff, 1, sizeof(buff), 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;
-}
-
-static int mp3_decode(void)
-{
- unsigned char *readPtr;
- int bytesLeft;
- int offset; // mp3 frame offset from readPtr
- int had_err;
- int err = 0;
-
- 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 = mp3_find_sync_word(mp3_input_buffer, bytesLeft);
- if (offset < 0) {
- lprintf("find_sync_word (%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;
-
- had_err = err;
- err = MP3Decode(mp3dec, &readPtr, &bytesLeft, cdda_out_buffer, 0);
- if (err) {
- if (err == ERR_MP3_MAINDATA_UNDERFLOW && !had_err) {
- // just need another frame
- mp3_file_pos += readPtr - mp3_input_buffer;
- continue;
- }
- if (err == ERR_MP3_INDATA_UNDERFLOW && !had_err) {
- if (offset == 0)
- // something's really wrong here, frame had to fit
- mp3_file_pos = mp3_file_len;
- else
- mp3_file_pos += offset;
- continue;
- }
- if (-12 <= err && err <= -6) {
- // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_*
- // just try to skip the offending frame..
- mp3_file_pos += offset + 1;
- continue;
- }
- lprintf("MP3Decode err (%i/%i) %i\n", mp3_file_pos, mp3_file_len, err);
- mp3_file_pos = mp3_file_len;
- return 1;
- }
- mp3_file_pos += readPtr - mp3_input_buffer;
- }
- while (0);
-
- return 0;
-}
-
-void mp3_start_play(void *f_, int pos)
-{
- FILE *f = f_;
-
- mp3_file_len = mp3_file_pos = 0;
- mp3_current_file = NULL;
- mp3_buffer_offs = 0;
-
- if (!(PicoOpt & POPT_EN_MCD_CDDA) || f == NULL) // cdda disabled or no file?
- return;
-
- // must re-init decoder for new track
- if (mp3dec)
- MP3FreeDecoder(mp3dec);
- mp3dec = MP3InitDecoder();
-
- mp3_current_file = f;
- fseek(f, 0, SEEK_END);
- mp3_file_len = ftell(f);
-
- // search for first sync word, skipping stuff like ID3 tags
- while (mp3_file_pos < 128*1024) {
- int offs, bytes;
-
- fseek(f, mp3_file_pos, SEEK_SET);
- bytes = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), f);
- if (bytes < 4)
- break;
- offs = mp3_find_sync_word(mp3_input_buffer, bytes);
- if (offs >= 0) {
- mp3_file_pos += offs;
- break;
- }
- mp3_file_pos += bytes - 2;
- }
-
- // seek..
- if (pos) {
- unsigned long long pos64 = mp3_file_len - mp3_file_pos;
- pos64 *= pos;
- mp3_file_pos += pos64 >> 10;
- }
-
- mp3_decode();
-}
-
-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;
-
- if (mp3_current_file == NULL || mp3_file_pos >= mp3_file_len)
- return; /* no file / EOF */
-
- length_mp3 = length;
- if (PsndRate <= 11025 + 100) {
- mix_samples = mix_16h_to_32_s2;
- length_mp3 <<= 2; shr = 2;
- }
- else if (PsndRate <= 22050 + 100) {
- mix_samples = mix_16h_to_32_s1;
- length_mp3 <<= 1; shr = 1;
- }
-
- if (1152 - mp3_buffer_offs >= length_mp3) {
- mix_samples(buffer, cdda_out_buffer + mp3_buffer_offs*2, length<<1);
-
- mp3_buffer_offs += length_mp3;
- } else {
- int ret, left = 1152 - mp3_buffer_offs;
-
- mix_samples(buffer, cdda_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), cdda_out_buffer, (mp3_buffer_offs>>shr)<<1);
- } else
- mp3_buffer_offs = 0;
- }
-}
-
notaz.gp2x.de / libpicofe.git / blobdiff