| 1 | /* |
| 2 | * Some mp3 related code for Sega/Mega CD. |
| 3 | * Uses the Helix Fixed-point MP3 decoder |
| 4 | * (C) notaz, 2007-2009 |
| 5 | * |
| 6 | * This work is licensed under the terms of MAME license. |
| 7 | * See COPYING file in the top-level directory. |
| 8 | */ |
| 9 | |
| 10 | #include <stdio.h> |
| 11 | #include <string.h> |
| 12 | |
| 13 | #include <pico/pico_int.h> |
| 14 | #include <pico/sound/mix.h> |
| 15 | #include "helix/pub/mp3dec.h" |
| 16 | #include "mp3.h" |
| 17 | #include "lprintf.h" |
| 18 | |
| 19 | static HMP3Decoder mp3dec; |
| 20 | static unsigned char mp3_input_buffer[2 * 1024]; |
| 21 | |
| 22 | #ifdef __GP2X__ |
| 23 | #define mp3_update mp3_update_local |
| 24 | #define mp3_start_play mp3_start_play_local |
| 25 | #endif |
| 26 | |
| 27 | int mp3dec_decode(FILE *f, int *file_pos, int file_len) |
| 28 | { |
| 29 | unsigned char *readPtr; |
| 30 | int bytesLeft; |
| 31 | int offset; // mp3 frame offset from readPtr |
| 32 | int had_err; |
| 33 | int err = 0; |
| 34 | |
| 35 | do |
| 36 | { |
| 37 | if (*file_pos >= file_len) |
| 38 | return 1; /* EOF, nothing to do */ |
| 39 | |
| 40 | fseek(f, *file_pos, SEEK_SET); |
| 41 | bytesLeft = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), f); |
| 42 | |
| 43 | offset = mp3_find_sync_word(mp3_input_buffer, bytesLeft); |
| 44 | if (offset < 0) { |
| 45 | lprintf("find_sync_word (%i/%i) err %i\n", |
| 46 | *file_pos, file_len, offset); |
| 47 | *file_pos = file_len; |
| 48 | return 1; // EOF |
| 49 | } |
| 50 | readPtr = mp3_input_buffer + offset; |
| 51 | bytesLeft -= offset; |
| 52 | |
| 53 | had_err = err; |
| 54 | err = MP3Decode(mp3dec, &readPtr, &bytesLeft, cdda_out_buffer, 0); |
| 55 | if (err) { |
| 56 | if (err == ERR_MP3_MAINDATA_UNDERFLOW && !had_err) { |
| 57 | // just need another frame |
| 58 | *file_pos += readPtr - mp3_input_buffer; |
| 59 | continue; |
| 60 | } |
| 61 | if (err == ERR_MP3_INDATA_UNDERFLOW && !had_err) { |
| 62 | if (offset == 0) |
| 63 | // something's really wrong here, frame had to fit |
| 64 | *file_pos = file_len; |
| 65 | else |
| 66 | *file_pos += offset; |
| 67 | continue; |
| 68 | } |
| 69 | if (-12 <= err && err <= -6) { |
| 70 | // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_* |
| 71 | // just try to skip the offending frame.. |
| 72 | *file_pos += offset + 1; |
| 73 | continue; |
| 74 | } |
| 75 | lprintf("MP3Decode err (%i/%i) %i\n", |
| 76 | *file_pos, file_len, err); |
| 77 | *file_pos = file_len; |
| 78 | return 1; |
| 79 | } |
| 80 | *file_pos += readPtr - mp3_input_buffer; |
| 81 | } |
| 82 | while (0); |
| 83 | |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | int mp3dec_start(FILE *f, int fpos_start) |
| 88 | { |
| 89 | // must re-init decoder for new track |
| 90 | if (mp3dec) |
| 91 | MP3FreeDecoder(mp3dec); |
| 92 | mp3dec = MP3InitDecoder(); |
| 93 | |
| 94 | return (mp3dec == 0) ? -1 : 0; |
| 95 | } |