diff options
Diffstat (limited to 'lib/rbcodec/codecs/a52.c')
-rw-r--r-- | lib/rbcodec/codecs/a52.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/a52.c b/lib/rbcodec/codecs/a52.c new file mode 100644 index 0000000000..cb6e66dd05 --- /dev/null +++ b/lib/rbcodec/codecs/a52.c | |||
@@ -0,0 +1,192 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2005 Dave Chapman | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version 2 | ||
15 | * of the License, or (at your option) any later version. | ||
16 | * | ||
17 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
18 | * KIND, either express or implied. | ||
19 | * | ||
20 | ****************************************************************************/ | ||
21 | |||
22 | #include "codeclib.h" | ||
23 | #include <inttypes.h> /* Needed by a52.h */ | ||
24 | #include <codecs/liba52/config-a52.h> | ||
25 | #include <codecs/liba52/a52.h> | ||
26 | |||
27 | CODEC_HEADER | ||
28 | |||
29 | #define BUFFER_SIZE 4096 | ||
30 | |||
31 | #define A52_SAMPLESPERFRAME (6*256) | ||
32 | |||
33 | static a52_state_t *state; | ||
34 | static unsigned long samplesdone; | ||
35 | static unsigned long frequency; | ||
36 | |||
37 | /* used outside liba52 */ | ||
38 | static uint8_t buf[3840] IBSS_ATTR; | ||
39 | |||
40 | static inline void output_audio(sample_t *samples) | ||
41 | { | ||
42 | ci->yield(); | ||
43 | ci->pcmbuf_insert(&samples[0], &samples[256], 256); | ||
44 | } | ||
45 | |||
46 | static void a52_decode_data(uint8_t *start, uint8_t *end) | ||
47 | { | ||
48 | static uint8_t *bufptr = buf; | ||
49 | static uint8_t *bufpos = buf + 7; | ||
50 | /* | ||
51 | * sample_rate and flags are static because this routine could | ||
52 | * exit between the a52_syncinfo() and the ao_setup(), and we want | ||
53 | * to have the same values when we get back ! | ||
54 | */ | ||
55 | static int sample_rate; | ||
56 | static int flags; | ||
57 | int bit_rate; | ||
58 | int len; | ||
59 | |||
60 | while (1) { | ||
61 | len = end - start; | ||
62 | if (!len) | ||
63 | break; | ||
64 | if (len > bufpos - bufptr) | ||
65 | len = bufpos - bufptr; | ||
66 | memcpy(bufptr, start, len); | ||
67 | bufptr += len; | ||
68 | start += len; | ||
69 | if (bufptr == bufpos) { | ||
70 | if (bufpos == buf + 7) { | ||
71 | int length; | ||
72 | |||
73 | length = a52_syncinfo(buf, &flags, &sample_rate, &bit_rate); | ||
74 | if (!length) { | ||
75 | //DEBUGF("skip\n"); | ||
76 | for (bufptr = buf; bufptr < buf + 6; bufptr++) | ||
77 | bufptr[0] = bufptr[1]; | ||
78 | continue; | ||
79 | } | ||
80 | bufpos = buf + length; | ||
81 | } else { | ||
82 | /* Unity gain is 1 << 26, and we want to end up on 28 bits | ||
83 | of precision instead of the default 30. | ||
84 | */ | ||
85 | level_t level = 1 << 24; | ||
86 | sample_t bias = 0; | ||
87 | int i; | ||
88 | |||
89 | /* This is the configuration for the downmixing: */ | ||
90 | flags = A52_STEREO | A52_ADJUST_LEVEL; | ||
91 | |||
92 | if (a52_frame(state, buf, &flags, &level, bias)) | ||
93 | goto error; | ||
94 | a52_dynrng(state, NULL, NULL); | ||
95 | frequency = sample_rate; | ||
96 | |||
97 | /* An A52 frame consists of 6 blocks of 256 samples | ||
98 | So we decode and output them one block at a time */ | ||
99 | for (i = 0; i < 6; i++) { | ||
100 | if (a52_block(state)) | ||
101 | goto error; | ||
102 | output_audio(a52_samples(state)); | ||
103 | samplesdone += 256; | ||
104 | } | ||
105 | ci->set_elapsed(samplesdone/(frequency/1000)); | ||
106 | bufptr = buf; | ||
107 | bufpos = buf + 7; | ||
108 | continue; | ||
109 | error: | ||
110 | //logf("Error decoding A52 stream\n"); | ||
111 | bufptr = buf; | ||
112 | bufpos = buf + 7; | ||
113 | } | ||
114 | } | ||
115 | } | ||
116 | } | ||
117 | |||
118 | /* this is the codec entry point */ | ||
119 | enum codec_status codec_main(enum codec_entry_call_reason reason) | ||
120 | { | ||
121 | if (reason == CODEC_LOAD) { | ||
122 | /* Generic codec initialisation */ | ||
123 | ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED); | ||
124 | ci->configure(DSP_SET_SAMPLE_DEPTH, 28); | ||
125 | } | ||
126 | else if (reason == CODEC_UNLOAD) { | ||
127 | if (state) | ||
128 | a52_free(state); | ||
129 | } | ||
130 | |||
131 | return CODEC_OK; | ||
132 | } | ||
133 | |||
134 | /* this is called for each file to process */ | ||
135 | enum codec_status codec_run(void) | ||
136 | { | ||
137 | size_t n; | ||
138 | unsigned char *filebuf; | ||
139 | int sample_loc; | ||
140 | intptr_t param; | ||
141 | |||
142 | if (codec_init()) | ||
143 | return CODEC_ERROR; | ||
144 | |||
145 | ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency); | ||
146 | codec_set_replaygain(ci->id3); | ||
147 | |||
148 | /* Intialise the A52 decoder and check for success */ | ||
149 | state = a52_init(0); | ||
150 | |||
151 | samplesdone = 0; | ||
152 | |||
153 | /* The main decoding loop */ | ||
154 | if (ci->id3->offset) { | ||
155 | if (ci->seek_buffer(ci->id3->offset)) { | ||
156 | samplesdone = (ci->id3->offset / ci->id3->bytesperframe) * | ||
157 | A52_SAMPLESPERFRAME; | ||
158 | ci->set_elapsed(samplesdone/(ci->id3->frequency / 1000)); | ||
159 | } | ||
160 | } | ||
161 | else { | ||
162 | ci->seek_buffer(ci->id3->first_frame_offset); | ||
163 | ci->set_elapsed(0); | ||
164 | } | ||
165 | |||
166 | while (1) { | ||
167 | enum codec_command_action action = ci->get_command(¶m); | ||
168 | |||
169 | if (action == CODEC_ACTION_HALT) | ||
170 | break; | ||
171 | |||
172 | if (action == CODEC_ACTION_SEEK_TIME) { | ||
173 | sample_loc = param/1000 * ci->id3->frequency; | ||
174 | |||
175 | if (ci->seek_buffer((sample_loc/A52_SAMPLESPERFRAME)*ci->id3->bytesperframe)) { | ||
176 | samplesdone = sample_loc; | ||
177 | ci->set_elapsed(samplesdone/(ci->id3->frequency/1000)); | ||
178 | } | ||
179 | ci->seek_complete(); | ||
180 | } | ||
181 | |||
182 | filebuf = ci->request_buffer(&n, BUFFER_SIZE); | ||
183 | |||
184 | if (n == 0) /* End of Stream */ | ||
185 | break; | ||
186 | |||
187 | a52_decode_data(filebuf, filebuf + n); | ||
188 | ci->advance_buffer(n); | ||
189 | } | ||
190 | |||
191 | return CODEC_OK; | ||
192 | } | ||