1 /***************************************************************************
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
10 * Copyright (C) 2005 Dave Chapman
12 * All files in this archive are subject to the GNU General Public License.
13 * See the file COPYING in the source tree root for full license agreement.
15 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
16 * KIND, either express or implied.
18 ****************************************************************************/
21 #include <codecs/libffmpegFLAC/decoder.h>
25 /* The output buffers containing the decoded samples (channels 0 and 1) */
26 int32_t decoded0
[MAX_BLOCKSIZE
] IBSS_ATTR_FLAC_DECODED0
;
27 int32_t decoded1
[MAX_BLOCKSIZE
] IBSS_ATTR
;
29 #define MAX_SUPPORTED_SEEKTABLE_SIZE 5000
31 /* Notes about seeking:
33 The full seek table consists of:
34 uint64_t sample (only 36 bits are used)
38 We also limit the sample and offset values to 32-bits - Rockbox doesn't
39 support files bigger than 2GB on FAT32 filesystems.
41 The reference FLAC encoder produces a seek table with points every
42 10 seconds, but this can be overridden by the user when encoding a file.
44 With the default settings, a typical 4 minute track will contain
47 Taking the extreme case of a Rockbox supported file to be a 2GB (compressed)
48 16-bit/44.1KHz mono stream with a likely uncompressed size of 4GB:
49 Total duration is: 48694 seconds (about 810 minutes - 13.5 hours)
50 Total number of seek points: 4869
52 Therefore we limit the number of seek points to 5000. This is a
53 very extreme case, and requires 5000*8=40000 bytes of storage.
55 If we come across a FLAC file with more than this number of seekpoints, we
56 just use the first 5000.
60 struct FLACseekpoints
{
66 struct FLACseekpoints seekpoints
[MAX_SUPPORTED_SEEKTABLE_SIZE
];
69 static int8_t *bit_buffer
;
70 static size_t buff_size
;
72 static bool flac_init(FLACContext
* fc
, int first_frame_offset
)
74 unsigned char buf
[255];
75 bool found_streaminfo
=false;
76 uint32_t seekpoint_hi
,seekpoint_lo
;
77 uint32_t offset_hi
,offset_lo
;
83 ci
->memset(fc
,0,sizeof(FLACContext
));
88 /* Skip any foreign tags at start of file */
89 ci
->seek_buffer(first_frame_offset
);
91 fc
->metadatalength
= first_frame_offset
;
93 if (ci
->read_filebuf(buf
, 4) < 4)
98 if (ci
->memcmp(buf
,"fLaC",4) != 0)
102 fc
->metadatalength
+= 4;
104 while (!endofmetadata
) {
105 if (ci
->read_filebuf(buf
, 4) < 4)
110 endofmetadata
=(buf
[0]&0x80);
111 blocklength
= (buf
[1] << 16) | (buf
[2] << 8) | buf
[3];
112 fc
->metadatalength
+=blocklength
+4;
114 if ((buf
[0] & 0x7f) == 0) /* 0 is the STREAMINFO block */
116 /* FIXME: Don't trust the value of blocklength, use actual return
117 * value in bytes instead */
118 ci
->read_filebuf(buf
, blocklength
);
120 fc
->filesize
= ci
->filesize
;
121 fc
->min_blocksize
= (buf
[0] << 8) | buf
[1];
122 fc
->max_blocksize
= (buf
[2] << 8) | buf
[3];
123 fc
->min_framesize
= (buf
[4] << 16) | (buf
[5] << 8) | buf
[6];
124 fc
->max_framesize
= (buf
[7] << 16) | (buf
[8] << 8) | buf
[9];
125 fc
->samplerate
= (buf
[10] << 12) | (buf
[11] << 4)
126 | ((buf
[12] & 0xf0) >> 4);
127 fc
->channels
= ((buf
[12]&0x0e)>>1) + 1;
128 fc
->bps
= (((buf
[12]&0x01) << 4) | ((buf
[13]&0xf0)>>4) ) + 1;
130 /* totalsamples is a 36-bit field, but we assume <= 32 bits are
132 fc
->totalsamples
= (buf
[14] << 24) | (buf
[15] << 16)
133 | (buf
[16] << 8) | buf
[17];
135 /* Calculate track length (in ms) and estimate the bitrate
137 fc
->length
= (fc
->totalsamples
/ fc
->samplerate
) * 1000;
139 found_streaminfo
=true;
140 } else if ((buf
[0] & 0x7f) == 3) { /* 3 is the SEEKTABLE block */
141 while ((nseekpoints
< MAX_SUPPORTED_SEEKTABLE_SIZE
) &&
142 (blocklength
>= 18)) {
143 n
=ci
->read_filebuf(buf
,18);
144 if (n
< 18) return false;
147 seekpoint_hi
=(buf
[0] << 24) | (buf
[1] << 16) |
148 (buf
[2] << 8) | buf
[3];
149 seekpoint_lo
=(buf
[4] << 24) | (buf
[5] << 16) |
150 (buf
[6] << 8) | buf
[7];
151 offset_hi
=(buf
[8] << 24) | (buf
[9] << 16) |
152 (buf
[10] << 8) | buf
[11];
153 offset_lo
=(buf
[12] << 24) | (buf
[13] << 16) |
154 (buf
[14] << 8) | buf
[15];
156 blocksize
=(buf
[16] << 8) | buf
[17];
158 /* Only store seekpoints where the high 32 bits are zero */
159 if ((seekpoint_hi
== 0) && (seekpoint_lo
!= 0xffffffff) &&
161 seekpoints
[nseekpoints
].sample
=seekpoint_lo
;
162 seekpoints
[nseekpoints
].offset
=offset_lo
;
163 seekpoints
[nseekpoints
].blocksize
=blocksize
;
167 /* Skip any unread seekpoints */
169 ci
->advance_buffer(blocklength
);
171 /* Skip to next metadata block */
172 ci
->advance_buffer(blocklength
);
176 if (found_streaminfo
) {
177 fc
->bitrate
= ((fc
->filesize
-fc
->metadatalength
) * 8) / fc
->length
;
184 /* Synchronize to next frame in stream - adapted from libFLAC 1.1.3b2 */
185 bool frame_sync(FLACContext
* fc
) {
189 /* Make sure we're byte aligned. */
190 align_get_bits(&fc
->gb
);
193 if(fc
->gb
.size_in_bits
- get_bits_count(&fc
->gb
) < 8) {
194 /* Error, end of bitstream, a valid stream should never reach here
195 * since the buffer should contain at least one frame header.
203 x
= get_bits(&fc
->gb
, 8);
205 if(x
== 0xff) { /* MAGIC NUMBER for first 8 frame sync bits. */
206 x
= get_bits(&fc
->gb
, 8);
207 /* We have to check if we just read two 0xff's in a row; the second
208 * may actually be the beginning of the sync code.
210 if(x
== 0xff) { /* MAGIC NUMBER for first 8 frame sync bits. */
213 else if(x
>> 2 == 0x3e) { /* MAGIC NUMBER for last 6 sync bits. */
214 /* Succesfully synced. */
220 /* Advance and init bit buffer to the new frame. */
221 ci
->advance_buffer((get_bits_count(&fc
->gb
)-16)>>3); /* consumed bytes */
222 bit_buffer
= ci
->request_buffer(&buff_size
, MAX_FRAMESIZE
+16);
223 init_get_bits(&fc
->gb
, bit_buffer
, buff_size
*8);
225 /* Decode the frame to verify the frame crc and
226 * fill fc with its metadata.
228 if(flac_decode_frame(fc
, decoded0
, decoded1
,
229 bit_buffer
, buff_size
, ci
->yield
) < 0) {
236 /* Seek to sample - adapted from libFLAC 1.1.3b2+ */
237 bool flac_seek(FLACContext
* fc
, uint32_t target_sample
) {
238 off_t orig_pos
= ci
->curpos
;
240 unsigned long lower_bound
, upper_bound
;
241 unsigned long lower_bound_sample
, upper_bound_sample
;
243 unsigned approx_bytes_per_frame
;
244 uint32_t this_frame_sample
= fc
->samplenumber
;
245 unsigned this_block_size
= fc
->blocksize
;
246 bool needs_seek
= true, first_seek
= true;
248 /* We are just guessing here. */
249 if(fc
->max_framesize
> 0)
250 approx_bytes_per_frame
= (fc
->max_framesize
+ fc
->min_framesize
)/2 + 1;
251 /* Check if it's a known fixed-blocksize stream. */
252 else if(fc
->min_blocksize
== fc
->max_blocksize
&& fc
->min_blocksize
> 0)
253 approx_bytes_per_frame
= fc
->min_blocksize
*fc
->channels
*fc
->bps
/8 + 64;
255 approx_bytes_per_frame
= 4608 * fc
->channels
* fc
->bps
/8 + 64;
257 /* Set an upper and lower bound on where in the stream we will search. */
258 lower_bound
= fc
->metadatalength
;
259 lower_bound_sample
= 0;
260 upper_bound
= fc
->filesize
;
261 upper_bound_sample
= fc
->totalsamples
>0 ? fc
->totalsamples
: target_sample
;
263 /* Refine the bounds if we have a seektable with suitable points. */
264 if(nseekpoints
> 0) {
265 /* Find the closest seek point <= target_sample, if it exists. */
266 for(i
= nseekpoints
-1; i
>= 0; i
--) {
267 if(seekpoints
[i
].sample
<= target_sample
)
270 if(i
>= 0) { /* i.e. we found a suitable seek point... */
271 lower_bound
= fc
->metadatalength
+ seekpoints
[i
].offset
;
272 lower_bound_sample
= seekpoints
[i
].sample
;
275 /* Find the closest seek point > target_sample, if it exists. */
276 for(i
= 0; i
< nseekpoints
; i
++) {
277 if(seekpoints
[i
].sample
> target_sample
)
280 if(i
< nseekpoints
) { /* i.e. we found a suitable seek point... */
281 upper_bound
= fc
->metadatalength
+ seekpoints
[i
].offset
;
282 upper_bound_sample
= seekpoints
[i
].sample
;
287 /* Check if bounds are still ok. */
288 if(lower_bound_sample
>= upper_bound_sample
||
289 lower_bound
> upper_bound
) {
293 /* Calculate new seek position */
295 pos
= (off_t
)(lower_bound
+
296 (((target_sample
- lower_bound_sample
) *
297 (int64_t)(upper_bound
- lower_bound
)) /
298 (upper_bound_sample
- lower_bound_sample
)) -
299 approx_bytes_per_frame
);
301 if(pos
>= (off_t
)upper_bound
)
302 pos
= (off_t
)upper_bound
-1;
303 if(pos
< (off_t
)lower_bound
)
304 pos
= (off_t
)lower_bound
;
307 if(!ci
->seek_buffer(pos
))
310 bit_buffer
= ci
->request_buffer(&buff_size
, MAX_FRAMESIZE
+16);
311 init_get_bits(&fc
->gb
, bit_buffer
, buff_size
*8);
313 /* Now we need to get a frame. It is possible for our seek
314 * to land in the middle of audio data that looks exactly like
315 * a frame header from a future version of an encoder. When
316 * that happens, frame_sync() will return false.
317 * But there is a remote possibility that it is properly
318 * synced at such a "future-codec frame", so to make sure,
319 * we wait to see several "unparseable" errors in a row before
323 unsigned unparseable_count
;
324 bool got_a_frame
= false;
325 for(unparseable_count
= 0; !got_a_frame
326 && unparseable_count
< 10; unparseable_count
++) {
331 ci
->seek_buffer(orig_pos
);
336 this_frame_sample
= fc
->samplenumber
;
337 this_block_size
= fc
->blocksize
;
339 if(target_sample
>= this_frame_sample
340 && target_sample
< this_frame_sample
+this_block_size
) {
341 /* Found the frame containing the target sample. */
342 fc
->sample_skip
= target_sample
- this_frame_sample
;
346 if(this_frame_sample
+ this_block_size
>= upper_bound_sample
&&
348 if(pos
== (off_t
)lower_bound
|| !needs_seek
) {
349 ci
->seek_buffer(orig_pos
);
352 /* Our last move backwards wasn't big enough, try again. */
353 approx_bytes_per_frame
*= 2;
356 /* Allow one seek over upper bound,
357 * required for streams with unknown total samples.
361 /* Make sure we are not seeking in a corrupted stream */
362 if(this_frame_sample
< lower_bound_sample
) {
363 ci
->seek_buffer(orig_pos
);
367 approx_bytes_per_frame
= this_block_size
*fc
->channels
*fc
->bps
/8 + 64;
369 /* We need to narrow the search. */
370 if(target_sample
< this_frame_sample
) {
371 upper_bound_sample
= this_frame_sample
;
372 upper_bound
= ci
->curpos
;
374 else { /* Target is beyond this frame. */
375 /* We are close, continue in decoding next frames. */
376 if(target_sample
< this_frame_sample
+ 4*this_block_size
) {
377 pos
= ci
->curpos
+ fc
->framesize
;
381 lower_bound_sample
= this_frame_sample
+ this_block_size
;
382 lower_bound
= ci
->curpos
+ fc
->framesize
;
389 /* Seek to file offset */
390 bool flac_seek_offset(FLACContext
* fc
, uint32_t offset
) {
391 unsigned unparseable_count
;
392 bool got_a_frame
= false;
394 if(!ci
->seek_buffer(offset
))
397 bit_buffer
= ci
->request_buffer(&buff_size
, MAX_FRAMESIZE
);
398 init_get_bits(&fc
->gb
, bit_buffer
, buff_size
*8);
400 for(unparseable_count
= 0; !got_a_frame
401 && unparseable_count
< 10; unparseable_count
++) {
407 ci
->seek_buffer(fc
->metadatalength
);
414 /* this is the codec entry point */
415 enum codec_status
codec_main(void)
419 uint32_t samplesdone
= 0;
420 uint32_t elapsedtime
;
427 /* Generic codec initialisation */
428 ci
->configure(CODEC_SET_FILEBUF_WATERMARK
, 1024*512);
429 ci
->configure(CODEC_SET_FILEBUF_CHUNKSIZE
, 1024*128);
431 ci
->configure(DSP_SET_SAMPLE_DEPTH
, FLAC_OUTPUT_DEPTH
-1);
435 /* Need to save offset for later use (cleared indirectly by flac_init) */
436 samplesdone
=ci
->id3
->offset
;
439 LOGF("FLAC: Error initialising codec\n");
440 retval
= CODEC_ERROR
;
444 if (!flac_init(&fc
,ci
->id3
->first_frame_offset
)) {
445 LOGF("FLAC: Error initialising codec\n");
446 retval
= CODEC_ERROR
;
450 while (!*ci
->taginfo_ready
&& !ci
->stop_codec
)
453 ci
->configure(DSP_SWITCH_FREQUENCY
, ci
->id3
->frequency
);
454 ci
->configure(DSP_SET_STEREO_MODE
, fc
.channels
== 1 ?
455 STEREO_MONO
: STEREO_NONINTERLEAVED
);
456 codec_set_replaygain(ci
->id3
);
459 flac_seek_offset(&fc
, samplesdone
);
463 /* The main decoding loop */
465 buf
= ci
->request_buffer(&bytesleft
, MAX_FRAMESIZE
);
468 if (ci
->stop_codec
|| ci
->new_track
) {
472 /* Deal with any pending seek requests */
474 if (flac_seek(&fc
,(uint32_t)(((uint64_t)(ci
->seek_time
-1)
475 *ci
->id3
->frequency
)/1000))) {
476 /* Refill the input buffer */
477 buf
= ci
->request_buffer(&bytesleft
, MAX_FRAMESIZE
);
482 if((res
=flac_decode_frame(&fc
,decoded0
,decoded1
,buf
,
483 bytesleft
,ci
->yield
)) < 0) {
484 LOGF("FLAC: Frame %d, error %d\n",frame
,res
);
485 retval
= CODEC_ERROR
;
488 consumed
=fc
.gb
.index
/8;
492 ci
->pcmbuf_insert(&decoded0
[fc
.sample_skip
], &decoded1
[fc
.sample_skip
],
493 fc
.blocksize
- fc
.sample_skip
);
497 /* Update the elapsed-time indicator */
498 samplesdone
=fc
.samplenumber
+fc
.blocksize
;
499 elapsedtime
=(samplesdone
*10)/(ci
->id3
->frequency
/100);
500 ci
->set_elapsed(elapsedtime
);
502 ci
->advance_buffer(consumed
);
504 buf
= ci
->request_buffer(&bytesleft
, MAX_FRAMESIZE
);
509 LOGF("FLAC: Decoded %ld samples\n",samplesdone
);
511 if (ci
->request_next_track())