cff531af |
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 | */ |
da42200b |
9 | |
10 | #include <stdio.h> |
11 | #include <string.h> |
12 | |
7c34867a |
13 | #include <pico/pico_int.h> |
14 | #include <pico/sound/mix.h> |
da42200b |
15 | #include "helix/pub/mp3dec.h" |
7c34867a |
16 | #include "mp3.h" |
da42200b |
17 | #include "lprintf.h" |
18 | |
da42200b |
19 | static HMP3Decoder mp3dec = 0; |
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20 | static FILE *mp3_current_file = NULL; |
21 | static int mp3_file_len = 0, mp3_file_pos = 0; |
da42200b |
22 | static int mp3_buffer_offs = 0; |
7c34867a |
23 | static unsigned char mp3_input_buffer[2*1024]; |
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24 | |
7c34867a |
25 | #ifdef __GP2X__ |
26 | #define mp3_update mp3_update_local |
27 | #define mp3_start_play mp3_start_play_local |
28 | #endif |
da42200b |
29 | |
30 | static int try_get_header(unsigned char *buff, MP3FrameInfo *fi) |
31 | { |
32 | int ret, offs1, offs = 0; |
33 | |
34 | while (1) |
35 | { |
7c18e34a |
36 | offs1 = mp3_find_sync_word(buff + offs, 2048 - offs); |
da42200b |
37 | if (offs1 < 0) return -2; |
38 | offs += offs1; |
39 | if (2048 - offs < 4) return -3; |
40 | |
41 | // printf("trying header %08x\n", *(int *)(buff + offs)); |
42 | |
43 | ret = MP3GetNextFrameInfo(mp3dec, fi, buff + offs); |
44 | if (ret == 0 && fi->bitrate != 0) break; |
45 | offs++; |
46 | } |
47 | |
48 | return ret; |
49 | } |
50 | |
7c18e34a |
51 | int mp3_get_bitrate(void *f_, int len) |
da42200b |
52 | { |
53 | unsigned char buff[2048]; |
54 | MP3FrameInfo fi; |
7c18e34a |
55 | FILE *f = f_; |
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56 | int ret; |
57 | |
7c18e34a |
58 | memset(buff, 0, sizeof(buff)); |
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59 | |
7c18e34a |
60 | if (mp3dec) |
61 | MP3FreeDecoder(mp3dec); |
091facb8 |
62 | mp3dec = MP3InitDecoder(); |
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63 | |
64 | fseek(f, 0, SEEK_SET); |
7c18e34a |
65 | ret = fread(buff, 1, sizeof(buff), f); |
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66 | fseek(f, 0, SEEK_SET); |
7c18e34a |
67 | if (ret <= 0) |
68 | return -1; |
da42200b |
69 | |
70 | ret = try_get_header(buff, &fi); |
71 | if (ret != 0 || fi.bitrate == 0) { |
72 | // try to read somewhere around the middle |
73 | fseek(f, len>>1, SEEK_SET); |
74 | fread(buff, 1, 2048, f); |
75 | fseek(f, 0, SEEK_SET); |
76 | ret = try_get_header(buff, &fi); |
77 | } |
7c18e34a |
78 | if (ret != 0) |
79 | return ret; |
da42200b |
80 | |
81 | // printf("bitrate: %i\n", fi.bitrate / 1000); |
82 | |
83 | return fi.bitrate / 1000; |
84 | } |
85 | |
da42200b |
86 | static int mp3_decode(void) |
87 | { |
88 | unsigned char *readPtr; |
89 | int bytesLeft; |
90 | int offset; // mp3 frame offset from readPtr |
7c34867a |
91 | int had_err; |
92 | int err = 0; |
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93 | |
94 | do |
95 | { |
7c34867a |
96 | if (mp3_file_pos >= mp3_file_len) |
97 | return 1; /* EOF, nothing to do */ |
da42200b |
98 | |
99 | fseek(mp3_current_file, mp3_file_pos, SEEK_SET); |
100 | bytesLeft = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), mp3_current_file); |
101 | |
7c18e34a |
102 | offset = mp3_find_sync_word(mp3_input_buffer, bytesLeft); |
da42200b |
103 | if (offset < 0) { |
7c34867a |
104 | lprintf("find_sync_word (%i/%i) err %i\n", mp3_file_pos, mp3_file_len, offset); |
da42200b |
105 | mp3_file_pos = mp3_file_len; |
106 | return 1; // EOF |
107 | } |
108 | readPtr = mp3_input_buffer + offset; |
109 | bytesLeft -= offset; |
110 | |
7c34867a |
111 | had_err = err; |
c9e1affc |
112 | err = MP3Decode(mp3dec, &readPtr, &bytesLeft, cdda_out_buffer, 0); |
da42200b |
113 | if (err) { |
7c34867a |
114 | if (err == ERR_MP3_MAINDATA_UNDERFLOW && !had_err) { |
115 | // just need another frame |
116 | mp3_file_pos += readPtr - mp3_input_buffer; |
117 | continue; |
118 | } |
119 | if (err == ERR_MP3_INDATA_UNDERFLOW && !had_err) { |
da42200b |
120 | if (offset == 0) |
121 | // something's really wrong here, frame had to fit |
122 | mp3_file_pos = mp3_file_len; |
123 | else |
124 | mp3_file_pos += offset; |
125 | continue; |
7c34867a |
126 | } |
127 | if (-12 <= err && err <= -6) { |
da42200b |
128 | // ERR_MP3_INVALID_FRAMEHEADER, ERR_MP3_INVALID_* |
129 | // just try to skip the offending frame.. |
130 | mp3_file_pos += offset + 1; |
131 | continue; |
132 | } |
7c34867a |
133 | lprintf("MP3Decode err (%i/%i) %i\n", mp3_file_pos, mp3_file_len, err); |
da42200b |
134 | mp3_file_pos = mp3_file_len; |
135 | return 1; |
136 | } |
137 | mp3_file_pos += readPtr - mp3_input_buffer; |
138 | } |
139 | while (0); |
140 | |
141 | return 0; |
142 | } |
143 | |
7c18e34a |
144 | void mp3_start_play(void *f_, int pos) |
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145 | { |
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146 | FILE *f = f_; |
147 | |
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148 | mp3_file_len = mp3_file_pos = 0; |
149 | mp3_current_file = NULL; |
150 | mp3_buffer_offs = 0; |
151 | |
7c34867a |
152 | if (!(PicoOpt & POPT_EN_MCD_CDDA) || f == NULL) // cdda disabled or no file? |
da42200b |
153 | return; |
154 | |
7c34867a |
155 | // must re-init decoder for new track |
156 | if (mp3dec) |
157 | MP3FreeDecoder(mp3dec); |
158 | mp3dec = MP3InitDecoder(); |
da42200b |
159 | |
160 | mp3_current_file = f; |
161 | fseek(f, 0, SEEK_END); |
162 | mp3_file_len = ftell(f); |
163 | |
7c18e34a |
164 | // search for first sync word, skipping stuff like ID3 tags |
165 | while (mp3_file_pos < 128*1024) { |
166 | int offs, bytes; |
167 | |
168 | fseek(f, mp3_file_pos, SEEK_SET); |
169 | bytes = fread(mp3_input_buffer, 1, sizeof(mp3_input_buffer), f); |
170 | if (bytes < 4) |
171 | break; |
172 | offs = mp3_find_sync_word(mp3_input_buffer, bytes); |
173 | if (offs >= 0) { |
174 | mp3_file_pos += offs; |
175 | break; |
176 | } |
177 | mp3_file_pos += bytes - 2; |
178 | } |
179 | |
da42200b |
180 | // seek.. |
181 | if (pos) { |
7c18e34a |
182 | unsigned long long pos64 = mp3_file_len - mp3_file_pos; |
7c34867a |
183 | pos64 *= pos; |
7c18e34a |
184 | mp3_file_pos += pos64 >> 10; |
da42200b |
185 | } |
186 | |
187 | mp3_decode(); |
188 | } |
189 | |
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190 | void mp3_update(int *buffer, int length, int stereo) |
191 | { |
192 | int length_mp3, shr = 0; |
193 | void (*mix_samples)(int *dest_buf, short *mp3_buf, int count) = mix_16h_to_32; |
194 | |
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195 | if (mp3_current_file == NULL || mp3_file_pos >= mp3_file_len) |
196 | return; /* no file / EOF */ |
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197 | |
198 | length_mp3 = length; |
02da059d |
199 | if (PsndRate <= 11025 + 100) { |
200 | mix_samples = mix_16h_to_32_s2; |
201 | length_mp3 <<= 2; shr = 2; |
202 | } |
203 | else if (PsndRate <= 22050 + 100) { |
204 | mix_samples = mix_16h_to_32_s1; |
205 | length_mp3 <<= 1; shr = 1; |
206 | } |
da42200b |
207 | |
208 | if (1152 - mp3_buffer_offs >= length_mp3) { |
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209 | mix_samples(buffer, cdda_out_buffer + mp3_buffer_offs*2, length<<1); |
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210 | |
211 | mp3_buffer_offs += length_mp3; |
212 | } else { |
213 | int ret, left = 1152 - mp3_buffer_offs; |
214 | |
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215 | mix_samples(buffer, cdda_out_buffer + mp3_buffer_offs*2, (left>>shr)<<1); |
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216 | ret = mp3_decode(); |
217 | if (ret == 0) { |
218 | mp3_buffer_offs = length_mp3 - left; |
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219 | mix_samples(buffer + ((left>>shr)<<1), cdda_out_buffer, (mp3_buffer_offs>>shr)<<1); |
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220 | } else |
221 | mp3_buffer_offs = 0; |
222 | } |
223 | } |
224 | |