Merge branch 'dev'
[picodrive.git] / platform / common / mp3_libavcodec.c
... / ...
CommitLineData
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
19static AVCodecContext *ctx;
20
21/* avoid compile time linking to libavcodec due to huge list of it's deps..
22 * we also use this old API as newer one is not available on pandora */
23void (*p_av_init_packet)(AVPacket *pkt);
24int (*p_avcodec_decode_audio3)(AVCodecContext *avctx, int16_t *samples,
25 int *frame_size_ptr, AVPacket *avpkt);
26
27int mp3dec_decode(FILE *f, int *file_pos, int file_len)
28{
29 unsigned char input_buf[2 * 1024];
30 int frame_size;
31 AVPacket avpkt;
32 int bytes_in;
33 int bytes_out;
34 int offset;
35 int len;
36
37 p_av_init_packet(&avpkt);
38
39 do
40 {
41 if (*file_pos >= file_len)
42 return 1; // EOF, nothing to do
43
44 fseek(f, *file_pos, SEEK_SET);
45 bytes_in = fread(input_buf, 1, sizeof(input_buf), f);
46
47 offset = mp3_find_sync_word(input_buf, bytes_in);
48 if (offset < 0) {
49 lprintf("find_sync_word (%i/%i) err %i\n",
50 *file_pos, file_len, offset);
51 *file_pos = file_len;
52 return 1; // EOF
53 }
54
55 // to avoid being flooded with "incorrect frame size" errors,
56 // we must calculate and pass exact frame size - lame
57 frame_size = mpeg1_l3_bitrates[input_buf[offset + 2] >> 4];
58 frame_size = frame_size * 144000 / 44100;
59 frame_size += (input_buf[offset + 2] >> 1) & 1;
60
61 if (offset > 0 && bytes_in - offset < frame_size) {
62 // underflow
63 *file_pos += offset;
64 continue;
65 }
66
67 avpkt.data = input_buf + offset;
68 avpkt.size = frame_size;
69 bytes_out = sizeof(cdda_out_buffer);
70#if LIBAVCODEC_VERSION_MAJOR < 53
71 // stupidity in v52: enforces this size even when
72 // it doesn't need/use that much at all
73 bytes_out = AVCODEC_MAX_AUDIO_FRAME_SIZE;
74#endif
75
76 len = p_avcodec_decode_audio3(ctx, cdda_out_buffer,
77 &bytes_out, &avpkt);
78 if (len <= 0) {
79 lprintf("mp3 decode err (%i/%i) %i\n",
80 *file_pos, file_len, len);
81
82 // attempt to skip the offending frame..
83 *file_pos += offset + 1;
84 continue;
85 }
86
87 *file_pos += offset + len;
88 }
89 while (0);
90
91 return 0;
92}
93
94int mp3dec_start(FILE *f, int fpos_start)
95{
96 void (*avcodec_register_all)(void);
97 AVCodec *(*avcodec_find_decoder)(enum CodecID id);
98 AVCodecContext *(*avcodec_alloc_context)(void);
99 int (*avcodec_open)(AVCodecContext *avctx, AVCodec *codec);
100 void (*av_free)(void *ptr);
101 AVCodec *codec;
102 void *soh;
103 int ret;
104
105 if (ctx != NULL)
106 return 0;
107
108 // either v52 or v53 should be ok
109 soh = dlopen("libavcodec.so.52", RTLD_NOW);
110 if (soh == NULL)
111 soh = dlopen("libavcodec.so.53", RTLD_NOW);
112 if (soh == NULL) {
113 lprintf("mp3dec: load libavcodec.so: %s\n", dlerror());
114 return -1;
115 }
116
117 avcodec_register_all = dlsym(soh, "avcodec_register_all");
118 avcodec_find_decoder = dlsym(soh, "avcodec_find_decoder");
119 avcodec_alloc_context = dlsym(soh, "avcodec_alloc_context");
120 avcodec_open = dlsym(soh, "avcodec_open");
121 av_free = dlsym(soh, "av_free");
122 p_av_init_packet = dlsym(soh, "av_init_packet");
123 p_avcodec_decode_audio3 = dlsym(soh, "avcodec_decode_audio3");
124
125 if (avcodec_register_all == NULL || avcodec_find_decoder == NULL
126 || avcodec_alloc_context == NULL || avcodec_open == NULL
127 || av_free == NULL
128 || p_av_init_packet == NULL || p_avcodec_decode_audio3 == NULL)
129 {
130 lprintf("mp3dec: missing symbol(s) in libavcodec.so\n");
131 dlclose(soh);
132 return -1;
133 }
134
135 // init decoder
136
137 //avcodec_init();
138 avcodec_register_all();
139
140 // AV_CODEC_ID_MP3 ?
141 codec = avcodec_find_decoder(CODEC_ID_MP3);
142 if (codec == NULL) {
143 lprintf("mp3dec: codec missing\n");
144 return -1;
145 }
146
147 ctx = avcodec_alloc_context();
148 if (ctx == NULL) {
149 lprintf("mp3dec: avcodec_alloc_context failed\n");
150 return -1;
151 }
152
153 ret = avcodec_open(ctx, codec);
154 if (ret < 0) {
155 lprintf("mp3dec: avcodec_open failed: %d\n", ret);
156 av_free(ctx);
157 ctx = NULL;
158 return -1;
159 }
160
161 return 0;
162}