/* * Some mp3 related code for Sega/Mega CD. * Uses Libav/FFmpeg libavcodec * (C) notaz, 2013 * * This work is licensed under the terms of MAME license. * See COPYING file in the top-level directory. */ #include #include #include #include #include #include "mp3.h" #if LIBAVCODEC_VERSION_MAJOR < 55 #define AVCodecID CodecID #define AV_CODEC_ID_MP3 CODEC_ID_MP3 #define AV_CH_LAYOUT_STEREO CH_LAYOUT_STEREO #define AV_SAMPLE_FMT_S16 SAMPLE_FMT_S16 #define request_sample_fmt sample_fmt #endif static void *libavcodec; static AVCodecContext *ctx; /* avoid compile time linking to libavcodec due to huge list of it's deps.. * we also use this old API as newer one is not available on pandora */ void (*p_av_init_packet)(AVPacket *pkt); int (*p_avcodec_decode_audio3)(AVCodecContext *avctx, int16_t *samples, int *frame_size_ptr, AVPacket *avpkt); int mp3dec_decode(FILE *f, int *file_pos, int file_len) { unsigned char input_buf[2 * 1024]; int frame_size; AVPacket avpkt; int bytes_in; int bytes_out; int offset; int len = -1; int retry = 3; p_av_init_packet(&avpkt); do { if (*file_pos >= file_len) return 1; // EOF, nothing to do fseek(f, *file_pos, SEEK_SET); bytes_in = fread(input_buf, 1, sizeof(input_buf), f); offset = mp3_find_sync_word(input_buf, bytes_in); if (offset < 0) { lprintf("find_sync_word (%i/%i) err %i\n", *file_pos, file_len, offset); *file_pos = file_len; return 1; // EOF } *file_pos += offset; // to avoid being flooded with "incorrect frame size" errors, // we must calculate and pass exact frame size - lame frame_size = mpeg1_l3_bitrates[input_buf[offset + 2] >> 4]; frame_size = frame_size * 144000 / 44100; frame_size += (input_buf[offset + 2] >> 1) & 1; if (offset > 0 && bytes_in - offset < frame_size) { // underflow continue; } avpkt.data = input_buf + offset; avpkt.size = frame_size; bytes_out = sizeof(cdda_out_buffer); #if LIBAVCODEC_VERSION_MAJOR < 53 // stupidity in v52: enforces this size even when // it doesn't need/use that much at all bytes_out = AVCODEC_MAX_AUDIO_FRAME_SIZE; #endif len = p_avcodec_decode_audio3(ctx, cdda_out_buffer, &bytes_out, &avpkt); if (len <= 0) { lprintf("mp3 decode err (%i/%i) %i\n", *file_pos, file_len, len); // attempt to skip the offending frame.. *file_pos += 1; } else *file_pos += len; } while (len <= 0 && --retry > 0); return len <= 0; } int mp3dec_start(FILE *f, int fpos_start) { void (*avcodec_register_all)(void); AVCodec *(*avcodec_find_decoder)(enum AVCodecID id); #if LIBAVCODEC_VERSION_MAJOR < 54 AVCodecContext *(*avcodec_alloc_context)(void); int (*avcodec_open)(AVCodecContext *avctx, AVCodec *codec); #else AVCodecContext *(*avcodec_alloc_context)(AVCodec *); int (*avcodec_open)(AVCodecContext *avctx, AVCodec *codec, AVDictionary **); #endif void (*av_free)(void *ptr); AVCodec *codec; int ret; if (ctx != NULL) return 0; #if LIBAVCODEC_VERSION_MAJOR < 54 // either v52 or v53 should be ok if (libavcodec == NULL) libavcodec = dlopen("libavcodec.so.52", RTLD_NOW); if (libavcodec == NULL) libavcodec = dlopen("libavcodec.so.53", RTLD_NOW); #else if (libavcodec == NULL) libavcodec = dlopen("libavcodec.so", RTLD_NOW); #endif if (libavcodec == NULL) { lprintf("mp3dec: load libavcodec.so: %s\n", dlerror()); return -1; } avcodec_register_all = dlsym(libavcodec, "avcodec_register_all"); avcodec_find_decoder = dlsym(libavcodec, "avcodec_find_decoder"); #if LIBAVCODEC_VERSION_MAJOR < 54 avcodec_alloc_context = dlsym(libavcodec, "avcodec_alloc_context"); avcodec_open = dlsym(libavcodec, "avcodec_open"); #else avcodec_alloc_context = dlsym(libavcodec, "avcodec_alloc_context3"); avcodec_open = dlsym(libavcodec, "avcodec_open2"); #endif av_free = dlsym(libavcodec, "av_free"); p_av_init_packet = dlsym(libavcodec, "av_init_packet"); p_avcodec_decode_audio3 = dlsym(libavcodec, "avcodec_decode_audio3"); if (avcodec_register_all == NULL || avcodec_find_decoder == NULL || avcodec_alloc_context == NULL || avcodec_open == NULL || av_free == NULL || p_av_init_packet == NULL || p_avcodec_decode_audio3 == NULL) { lprintf("mp3dec: missing symbol(s) in libavcodec.so\n"); return -1; } // init decoder //avcodec_init(); avcodec_register_all(); codec = avcodec_find_decoder(AV_CODEC_ID_MP3); if (codec == NULL) { lprintf("mp3dec: codec missing\n"); return -1; } #if LIBAVCODEC_VERSION_MAJOR < 54 ctx = avcodec_alloc_context(); if (ctx == NULL) { lprintf("mp3dec: avcodec_alloc_context failed\n"); return -1; } #else ctx = avcodec_alloc_context(codec); if (ctx == NULL) { lprintf("mp3dec: avcodec_alloc_context failed\n"); return -1; } #endif ctx->request_channel_layout = AV_CH_LAYOUT_STEREO; ctx->request_sample_fmt = AV_SAMPLE_FMT_S16; ctx->sample_rate = 44100; #if LIBAVCODEC_VERSION_MAJOR < 54 ret = avcodec_open(ctx, codec); if (ret < 0) { lprintf("mp3dec: avcodec_open failed: %d\n", ret); av_free(ctx); ctx = NULL; return -1; } #else ret = avcodec_open(ctx, codec, NULL); if (ret < 0) { lprintf("mp3dec: avcodec_open failed: %d\n", ret); av_free(ctx); ctx = NULL; return -1; } #endif return 0; }