| 1 | /* |
| 2 | * Some mp3 related code for Sega/Mega CD. |
| 3 | * Uses Libav/FFmpeg libavcodec |
| 4 | * (C) notaz, 2013 |
| 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 | #include <libavcodec/avcodec.h> |
| 13 | #include <dlfcn.h> |
| 14 | |
| 15 | #include <pico/pico_int.h> |
| 16 | #include "../libpicofe/lprintf.h" |
| 17 | #include "mp3.h" |
| 18 | |
| 19 | #if LIBAVCODEC_VERSION_MAJOR < 55 |
| 20 | #define AVCodecID CodecID |
| 21 | #define AV_CODEC_ID_MP3 CODEC_ID_MP3 |
| 22 | #endif |
| 23 | |
| 24 | static AVCodecContext *ctx; |
| 25 | |
| 26 | /* avoid compile time linking to libavcodec due to huge list of it's deps.. |
| 27 | * we also use this old API as newer one is not available on pandora */ |
| 28 | void (*p_av_init_packet)(AVPacket *pkt); |
| 29 | int (*p_avcodec_decode_audio3)(AVCodecContext *avctx, int16_t *samples, |
| 30 | int *frame_size_ptr, AVPacket *avpkt); |
| 31 | |
| 32 | int mp3dec_decode(FILE *f, int *file_pos, int file_len) |
| 33 | { |
| 34 | unsigned char input_buf[2 * 1024]; |
| 35 | int frame_size; |
| 36 | AVPacket avpkt; |
| 37 | int bytes_in; |
| 38 | int bytes_out; |
| 39 | int offset; |
| 40 | int len; |
| 41 | |
| 42 | p_av_init_packet(&avpkt); |
| 43 | |
| 44 | do |
| 45 | { |
| 46 | if (*file_pos >= file_len) |
| 47 | return 1; // EOF, nothing to do |
| 48 | |
| 49 | fseek(f, *file_pos, SEEK_SET); |
| 50 | bytes_in = fread(input_buf, 1, sizeof(input_buf), f); |
| 51 | |
| 52 | offset = mp3_find_sync_word(input_buf, bytes_in); |
| 53 | if (offset < 0) { |
| 54 | lprintf("find_sync_word (%i/%i) err %i\n", |
| 55 | *file_pos, file_len, offset); |
| 56 | *file_pos = file_len; |
| 57 | return 1; // EOF |
| 58 | } |
| 59 | |
| 60 | // to avoid being flooded with "incorrect frame size" errors, |
| 61 | // we must calculate and pass exact frame size - lame |
| 62 | frame_size = mpeg1_l3_bitrates[input_buf[offset + 2] >> 4]; |
| 63 | frame_size = frame_size * 144000 / 44100; |
| 64 | frame_size += (input_buf[offset + 2] >> 1) & 1; |
| 65 | |
| 66 | if (offset > 0 && bytes_in - offset < frame_size) { |
| 67 | // underflow |
| 68 | *file_pos += offset; |
| 69 | continue; |
| 70 | } |
| 71 | |
| 72 | avpkt.data = input_buf + offset; |
| 73 | avpkt.size = frame_size; |
| 74 | bytes_out = sizeof(cdda_out_buffer); |
| 75 | #if LIBAVCODEC_VERSION_MAJOR < 53 |
| 76 | // stupidity in v52: enforces this size even when |
| 77 | // it doesn't need/use that much at all |
| 78 | bytes_out = AVCODEC_MAX_AUDIO_FRAME_SIZE; |
| 79 | #endif |
| 80 | |
| 81 | len = p_avcodec_decode_audio3(ctx, cdda_out_buffer, |
| 82 | &bytes_out, &avpkt); |
| 83 | if (len <= 0) { |
| 84 | lprintf("mp3 decode err (%i/%i) %i\n", |
| 85 | *file_pos, file_len, len); |
| 86 | |
| 87 | // attempt to skip the offending frame.. |
| 88 | *file_pos += offset + 1; |
| 89 | continue; |
| 90 | } |
| 91 | |
| 92 | *file_pos += offset + len; |
| 93 | } |
| 94 | while (0); |
| 95 | |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | int mp3dec_start(FILE *f, int fpos_start) |
| 100 | { |
| 101 | void (*avcodec_register_all)(void); |
| 102 | AVCodec *(*avcodec_find_decoder)(enum AVCodecID id); |
| 103 | AVCodecContext *(*avcodec_alloc_context)(void); |
| 104 | int (*avcodec_open)(AVCodecContext *avctx, AVCodec *codec); |
| 105 | void (*av_free)(void *ptr); |
| 106 | AVCodec *codec; |
| 107 | void *soh; |
| 108 | int ret; |
| 109 | |
| 110 | if (ctx != NULL) |
| 111 | return 0; |
| 112 | |
| 113 | // either v52 or v53 should be ok |
| 114 | soh = dlopen("libavcodec.so.52", RTLD_NOW); |
| 115 | if (soh == NULL) |
| 116 | soh = dlopen("libavcodec.so.53", RTLD_NOW); |
| 117 | if (soh == NULL) { |
| 118 | lprintf("mp3dec: load libavcodec.so: %s\n", dlerror()); |
| 119 | return -1; |
| 120 | } |
| 121 | |
| 122 | avcodec_register_all = dlsym(soh, "avcodec_register_all"); |
| 123 | avcodec_find_decoder = dlsym(soh, "avcodec_find_decoder"); |
| 124 | avcodec_alloc_context = dlsym(soh, "avcodec_alloc_context"); |
| 125 | avcodec_open = dlsym(soh, "avcodec_open"); |
| 126 | av_free = dlsym(soh, "av_free"); |
| 127 | p_av_init_packet = dlsym(soh, "av_init_packet"); |
| 128 | p_avcodec_decode_audio3 = dlsym(soh, "avcodec_decode_audio3"); |
| 129 | |
| 130 | if (avcodec_register_all == NULL || avcodec_find_decoder == NULL |
| 131 | || avcodec_alloc_context == NULL || avcodec_open == NULL |
| 132 | || av_free == NULL |
| 133 | || p_av_init_packet == NULL || p_avcodec_decode_audio3 == NULL) |
| 134 | { |
| 135 | lprintf("mp3dec: missing symbol(s) in libavcodec.so\n"); |
| 136 | dlclose(soh); |
| 137 | return -1; |
| 138 | } |
| 139 | |
| 140 | // init decoder |
| 141 | |
| 142 | //avcodec_init(); |
| 143 | avcodec_register_all(); |
| 144 | |
| 145 | codec = avcodec_find_decoder(AV_CODEC_ID_MP3); |
| 146 | if (codec == NULL) { |
| 147 | lprintf("mp3dec: codec missing\n"); |
| 148 | return -1; |
| 149 | } |
| 150 | |
| 151 | ctx = avcodec_alloc_context(); |
| 152 | if (ctx == NULL) { |
| 153 | lprintf("mp3dec: avcodec_alloc_context failed\n"); |
| 154 | return -1; |
| 155 | } |
| 156 | |
| 157 | ret = avcodec_open(ctx, codec); |
| 158 | if (ret < 0) { |
| 159 | lprintf("mp3dec: avcodec_open failed: %d\n", ret); |
| 160 | av_free(ctx); |
| 161 | ctx = NULL; |
| 162 | return -1; |
| 163 | } |
| 164 | |
| 165 | return 0; |
| 166 | } |