1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2007 Dave Chapman
*
* ASF parsing code based on libasf by Juho Vähä-Herttua
* http://code.google.com/p/libasf/ libasf itself was based on the ASF
* parser in VLC - http://www.videolan.org/
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "codeclib.h"
#include "libasf/asf.h"
#include "libwma/wmadec.h"
CODEC_HEADER
/* The output buffer containing the decoded samples (channels 0 and 1)
BLOCK_MAX_SIZE is 2048 (samples) and MAX_CHANNELS is 2.
*/
static uint32_t decoded[BLOCK_MAX_SIZE * MAX_CHANNELS] IBSS_ATTR;
/* NOTE: WMADecodeContext is 120152 bytes (on x86) */
static WMADecodeContext wmadec;
/*entry point for seeks*/
static int seek(int ms, asf_waveformatex_t* wfx)
{
int time, duration, delta, temp, count=0;
/*estimate packet number from bitrate*/
int initial_packet = ci->curpos/wfx->packet_size;
int packet_num = (((int64_t)ms)*(wfx->bitrate>>3))/wfx->packet_size/1000;
int last_packet = ci->id3->filesize / wfx->packet_size;
if (packet_num > last_packet) {
packet_num = last_packet;
}
/*calculate byte address of the start of that packet*/
int packet_offset = packet_num*wfx->packet_size;
/*seek to estimated packet*/
ci->seek_buffer(ci->id3->first_frame_offset+packet_offset);
temp = ms;
while (1)
{
/*for very large files it can be difficult and unimportant to find the exact packet*/
count++;
/*check the time stamp of our packet*/
time = asf_get_timestamp(&duration, ci);
DEBUGF("seeked to %d ms with duration %d\n", time, duration);
if (time < 0) {
/*unknown error, try to recover*/
DEBUGF("UKNOWN SEEK ERROR\n");
ci->seek_buffer(ci->id3->first_frame_offset+initial_packet*wfx->packet_size);
/*seek failed so return time stamp of the initial packet*/
return asf_get_timestamp(&duration, ci);
}
if ((time+duration>=ms && time<=ms) || count > 10) {
DEBUGF("Found our packet! Now at %d packet\n", packet_num);
return time;
} else {
/*seek again*/
delta = ms-time;
/*estimate new packet number from bitrate and our current position*/
temp += delta;
packet_num = ((temp/1000)*(wfx->bitrate>>3) - (wfx->packet_size>>1))/wfx->packet_size; //round down!
packet_offset = packet_num*wfx->packet_size;
ci->seek_buffer(ci->id3->first_frame_offset+packet_offset);
}
}
}
/* this is the codec entry point */
enum codec_status codec_main(void)
{
uint32_t elapsedtime;
int retval;
asf_waveformatex_t wfx;
size_t resume_offset;
int i;
int wmares, res;
uint8_t* audiobuf;
int audiobufsize;
int packetlength = 0;
int errcount = 0;
/* Generic codec initialisation */
ci->configure(DSP_SET_SAMPLE_DEPTH, 29);
next_track:
/* Wait for the metadata to be read */
while (!*ci->taginfo_ready && !ci->stop_codec)
ci->sleep(1);
retval = CODEC_OK;
/* Remember the resume position - when the codec is opened, the
playback engine will reset it. */
resume_offset = ci->id3->offset;
restart_track:
if (codec_init()) {
LOGF("WMA: Error initialising codec\n");
retval = CODEC_ERROR;
goto exit;
}
/* Copy the format metadata we've stored in the id3 TOC field. This
saves us from parsing it again here. */
memcpy(&wfx, ci->id3->toc, sizeof(wfx));
if (wma_decode_init(&wmadec,&wfx) < 0) {
LOGF("WMA: Unsupported or corrupt file\n");
retval = CODEC_ERROR;
goto exit;
}
DEBUGF("**************** IN WMA.C ******************\n");
if (resume_offset > ci->id3->first_frame_offset)
{
/* Get start of current packet */
int packet_offset = (resume_offset - ci->id3->first_frame_offset)
% wfx.packet_size;
ci->seek_buffer(resume_offset - packet_offset);
elapsedtime = asf_get_timestamp(&i, ci);
ci->set_elapsed(elapsedtime);
}
else
{
/* Now advance the file position to the first frame */
ci->seek_buffer(ci->id3->first_frame_offset);
elapsedtime = 0;
}
resume_offset = 0;
ci->configure(DSP_SWITCH_FREQUENCY, wfx.rate);
ci->configure(DSP_SET_STEREO_MODE, wfx.channels == 1 ?
STEREO_MONO : STEREO_INTERLEAVED);
codec_set_replaygain(ci->id3);
/* The main decoding loop */
res = 1;
while (res >= 0)
{
ci->yield();
if (ci->stop_codec || ci->new_track) {
goto done;
}
/* Deal with any pending seek requests */
if (ci->seek_time){
if (ci->seek_time == 1) {
ci->seek_complete();
goto restart_track; /* Pretend you never saw this... */
}
elapsedtime = seek(ci->seek_time, &wfx);
if (elapsedtime < 1){
ci->seek_complete();
goto next_track;
}
/*DEBUGF("Seek returned %d\n", (int)elapsedtime);*/
ci->set_elapsed(elapsedtime);
/*flush the wma decoder state*/
wmadec.last_superframe_len = 0;
wmadec.last_bitoffset = 0;
ci->seek_complete();
}
errcount = 0;
new_packet:
res = asf_read_packet(&audiobuf, &audiobufsize, &packetlength, &wfx, ci);
if (res < 0) {
/* We'll try to recover from a parse error a certain number of
* times. If we succeed, the error counter will be reset.
*/
errcount++;
DEBUGF("read_packet error %d, errcount %d\n",wmares, errcount);
if (errcount > 5) {
goto done;
} else {
ci->advance_buffer(packetlength);
goto new_packet;
}
} else if (res > 0) {
wma_decode_superframe_init(&wmadec, audiobuf, audiobufsize);
for (i=0; i < wmadec.nb_frames; i++)
{
wmares = wma_decode_superframe_frame(&wmadec,
decoded,
audiobuf, audiobufsize);
ci->yield ();
if (wmares < 0) {
/* Do the above, but for errors in decode. */
errcount++;
DEBUGF("WMA decode error %d, errcount %d\n",wmares, errcount);
if (errcount > 5) {
goto done;
} else {
ci->advance_buffer(packetlength);
goto new_packet;
}
} else if (wmares > 0) {
ci->pcmbuf_insert(decoded, NULL, wmares);
elapsedtime += (wmares*10)/(wfx.rate/100);
ci->set_elapsed(elapsedtime);
}
ci->yield();
}
}
ci->advance_buffer(packetlength);
}
retval = CODEC_OK;
done:
/*LOGF("WMA: Decoded %ld samples\n",elapsedtime*wfx.rate/1000);*/
if (ci->request_next_track())
goto next_track;
exit:
return retval;
}
|
