39e78163538825e696cceca43e03bf89d8db2c64
[paraslash.git] / fecdec_filter.c
1 /*
2 * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file fecdec_filter.c A filter that fec-decodes an audio stream. */
8
9 #include <regex.h>
10 #include <stdbool.h>
11
12 #include <dirent.h>
13 #include "para.h"
14 #include "error.h"
15 #include "list.h"
16 #include "sched.h"
17 #include "ggo.h"
18 #include "buffer_tree.h"
19 #include "filter.h"
20 #include "string.h"
21 #include "portable_io.h"
22 #include "fec.h"
23 #include "fd.h"
24
25 /**
26 * How many FEC groups to store in memory.
27 *
28 * Packet reordering requires to keep more than one FEC group in memory because
29 * slices belonging to the next FEC group may arrive before the current FEC group
30 * is complete.
31 */
32 #define NUM_FEC_GROUPS 3
33
34 /** Default size of the output buffer of the fecdec filter. */
35 #define FECDEC_DEFAULT_OUTBUF_SIZE (3 * 1024)
36 /** Maximal size of the output buffer of the fecdec filter. */
37 #define FECDEC_MAX_OUTBUF_SIZE (1024 * 1024)
38
39 /** Data read from the header of a slice. */
40 struct fec_header {
41 /** Total number of slices in this group. */
42 uint8_t slices_per_group;
43 /** Number of slices needed to start decoding. */
44 uint8_t data_slices_per_group;
45 /** Size of the ogg vorbis/wma header (zero for mp3, aac). */
46 uint32_t audio_header_size;
47 /** Number of the FEC group this slice belongs to. */
48 uint32_t group_num;
49 /** Size of the data in this FEC group. */
50 uint32_t group_bytes;
51 /** Number of this slice in the group. */
52 uint8_t slice_num;
53 /** Used data bytes of this slice. */
54 uint16_t slice_bytes;
55 /** Non-zero if this group is the beginning of the stream. */
56 uint8_t bos;
57 /** Non-zero if this stream embedds audio headers into fec groups. */
58 uint8_t header_stream;
59 };
60
61 /**
62 * The status of one partially received FEC group.
63 */
64 struct fecdec_group {
65 /** The header read from the last slice. */
66 struct fec_header h;
67 /** How many slices received so far. */
68 int num_received_slices;
69 /** The size of the \a idx and the \a data arrays below. */
70 int num_slices;
71 /** Array of indices of the received slices. */
72 int *idx;
73 /** Content of the received slices. */
74 unsigned char **data;
75 };
76
77 /**
78 * Data private to the fecdec filter.
79 */
80 struct private_fecdec_data {
81 /** Used by the fec core code. */
82 struct fec_parms *fec;
83 /** Keeps track of what was received so far. */
84 struct fecdec_group groups[NUM_FEC_GROUPS];
85 /** Whether an audio file header was already received. */
86 int have_header;
87 /** Points to the first received group. */
88 struct fecdec_group *first_complete_group;
89 };
90
91 /** Iterate over all fecdec groups. */
92 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
93 (g) < (d)->groups + NUM_FEC_GROUPS; (g)++)
94
95 static int group_complete(struct fecdec_group *fg)
96 {
97 return fg->num_received_slices >= fg->h.data_slices_per_group;
98 }
99
100 static int group_empty(struct fecdec_group *fg)
101 {
102 return fg->num_received_slices == 0;
103 }
104
105 static void clear_group(struct fecdec_group *fg)
106 {
107 int i;
108
109 for (i = 0; i < fg->num_slices; i++) {
110 free(fg->data[i]);
111 fg->data[i] = NULL;
112 fg->idx[i] = -1;
113 }
114 free(fg->data);
115 fg->data = NULL;
116 free(fg->idx);
117 fg->idx = NULL;
118 fg->num_slices = 0;
119 memset(&fg->h, 0, sizeof(struct fec_header));
120 fg->num_received_slices = 0;
121 }
122
123 static int find_group(struct fec_header *h,
124 struct private_fecdec_data *pfd, struct fecdec_group **result)
125 {
126 struct fecdec_group *fg;
127
128 FOR_EACH_FECDEC_GROUP(fg, pfd) {
129 if (fg->h.group_num != h->group_num)
130 continue;
131 if (fg->num_received_slices == 0)
132 goto success;
133 if (fg->h.slices_per_group != h->slices_per_group)
134 return -E_BAD_FEC_HEADER;
135 if (fg->h.data_slices_per_group != h->data_slices_per_group)
136 return -E_BAD_FEC_HEADER;
137 if (fg->h.group_bytes != h->group_bytes)
138 return -E_BAD_FEC_HEADER;
139 success:
140 *result = fg;
141 return 1;
142 }
143 return 0;
144 }
145
146 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
147 {
148 struct fecdec_group *fg;
149
150 FOR_EACH_FECDEC_GROUP(fg, pfd) {
151 if (fg->num_received_slices == 0)
152 return fg;
153 }
154 return NULL;
155 }
156
157 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
158 {
159 struct fecdec_group *fg;
160
161 FOR_EACH_FECDEC_GROUP(fg, pfd) {
162 if (!group_complete(fg))
163 continue;
164 /*
165 * Don't clear the first complete group if it has not yet been
166 * decoded.
167 */
168 if (fg == pfd->first_complete_group)
169 continue;
170 clear_group(fg);
171 return fg;
172 }
173 return NULL;
174 }
175
176 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
177 {
178 struct fecdec_group *fg, *oldest = NULL;
179
180 FOR_EACH_FECDEC_GROUP(fg, pfd) {
181 if (!oldest || oldest->h.group_num > fg->h.group_num)
182 oldest = fg;
183 }
184 if (!group_complete(oldest) && !group_empty(oldest))
185 PARA_WARNING_LOG("Clearing incomplete group %d "
186 "(contains %d slices)\n", oldest->h.group_num,
187 oldest->num_received_slices);
188 if (oldest == pfd->first_complete_group)
189 pfd->first_complete_group = NULL;
190 clear_group(oldest);
191 return oldest;
192 }
193
194 /* returns 1 if the group was found, 0 if not, negative on errors */
195 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
196 struct fecdec_group **result)
197 {
198 struct fecdec_group *fg;
199 int ret = find_group(h, pfd, &fg);
200
201 if (ret < 0)
202 return ret;
203 if (ret > 0) /* found group */
204 goto success;
205 /* group not found */
206 fg = find_unused_group(pfd);
207 if (fg)
208 goto success;
209 fg = try_to_free_group(pfd);
210 if (fg)
211 goto success;
212 fg = free_oldest_group(pfd);
213 ret = 0;
214 success:
215 fg->h = *h;
216 *result = fg;
217 return ret;
218 }
219
220 /*
221 * returns 1 if slice was added, zero otherwise (because the group was already
222 * complete). In any case the number of received slices is being increased by
223 * one.
224 */
225 static int add_slice(char *buf, struct fecdec_group *fg)
226 {
227 int r, slice_num;
228
229 if (group_complete(fg)) {
230 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
231 fg->h.group_num, fg->h.slice_num);
232 fg->num_received_slices++;
233 return 0;
234 }
235 slice_num = fg->h.slice_num;
236 if (fg->num_slices == 0) {
237 fg->num_slices = fg->h.slices_per_group;
238 fg->idx = para_malloc(fg->num_slices * sizeof(int));
239 fg->data = para_malloc(fg->num_slices * sizeof(unsigned char *));
240 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
241 }
242 r = fg->num_received_slices;
243 fg->idx[r] = slice_num;
244 fg->data[r] = para_malloc(fg->h.slice_bytes);
245 memcpy(fg->data[r], buf, fg->h.slice_bytes);
246 fg->num_received_slices++;
247 return 1;
248 }
249
250 /**
251 * The different states of a complete FEC group.
252 *
253 * Even if a FEC group has been received successfully, it probably can not be
254 * used right away because some streams (ogg, wma) need to receive an audio
255 * file header before decoding can start.
256 */
257 enum fec_group_usability {
258 /** Drop the group (because we did not receive the header yet). */
259 FEC_GROUP_UNUSABLE,
260 /** Use all data in the group. */
261 FEC_GROUP_USABLE,
262 /** Use the group, but drop its audio file header. */
263 FEC_GROUP_USABLE_SKIP_HEADER,
264 /** Use the group, including its header. */
265 FEC_GROUP_USABLE_WITH_HEADER
266 };
267
268 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
269 struct private_fecdec_data *pfd)
270 {
271 struct fec_header *h = &fg->h;
272
273 if (!h->header_stream)
274 return FEC_GROUP_USABLE;
275 if (pfd->have_header) {
276 if (h->audio_header_size)
277 return FEC_GROUP_USABLE_SKIP_HEADER;
278 return FEC_GROUP_USABLE;
279 }
280 if (fg->h.bos)
281 return FEC_GROUP_USABLE;
282 if (fg->h.audio_header_size)
283 return FEC_GROUP_USABLE_WITH_HEADER;
284 return FEC_GROUP_UNUSABLE;
285 }
286
287 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
288 {
289 int i, ret, sb = fg->h.slice_bytes;
290 size_t written, need;
291 struct private_fecdec_data *pfd = fn->private_data;
292 enum fec_group_usability u = group_is_usable(fg, pfd);
293 char *buf = NULL, *p;
294
295 if (u == FEC_GROUP_UNUSABLE) {
296 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
297 return 0;
298 }
299 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg->h.group_num,
300 fg->h.data_slices_per_group);
301 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
302 if (ret < 0)
303 return ret;
304 pfd->have_header = 1;
305 i = 0;
306 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
307 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
308 / fg->h.slice_bytes;
309 PARA_DEBUG_LOG("skipping %d header slices\n", i);
310 }
311 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
312 fg->h.group_num, fg->h.group_bytes,
313 fg->h.data_slices_per_group * sb);
314 need = fn->loaded + (fg->h.data_slices_per_group - i) * sb;
315 if (fn->btrn) {
316 buf = para_malloc(need);
317 p = buf;
318 } else {
319 if (need > fn->bufsize) {
320 fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
321 if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
322 return -E_FECDEC_OVERRUN;
323 PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
324 fn->buf = para_realloc(fn->buf, fn->bufsize);
325 }
326 p = fn->buf + fn->loaded;
327 }
328 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
329 PARA_INFO_LOG("writing audio file header\n");
330 written = 0;
331 for (i = 0; i < fg->h.data_slices_per_group; i++) {
332 size_t n = sb;
333 if (written >= fg->h.audio_header_size)
334 break;
335 if (sb + written > fg->h.audio_header_size)
336 n = fg->h.audio_header_size - written;
337 memcpy(p + written, fg->data[i], n);
338 fn->loaded += n;
339 written += n;
340 }
341 p += written;
342 }
343 written = 0;
344 for (; i < fg->h.data_slices_per_group; i++) {
345 size_t n = sb;
346 if (n + written > fg->h.group_bytes)
347 n = fg->h.group_bytes - written;
348 memcpy(p + written, fg->data[i], n);
349 fn->loaded += n;
350 written += n;
351 }
352 p += written;
353 if (fn->btrn)
354 btr_add_output(buf, p - buf, fn->btrn);
355 return 0;
356 }
357
358 /**
359 * Read a fec header from a buffer.
360 *
361 * \param buf The buffer to write to.
362 * \param h The fec header to write.
363 */
364 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
365 {
366 uint32_t magic;
367
368 if (len < FEC_HEADER_SIZE)
369 return 0;
370 magic = read_u32(buf);
371 if (magic != FEC_MAGIC)
372 return -E_BAD_FEC_HEADER;
373 h->slices_per_group = read_u8(buf + 4);
374 h->data_slices_per_group = read_u8(buf + 5);
375 h->audio_header_size = read_u32(buf + 6);
376
377 h->group_num = read_u32(buf + 10);
378 h->group_bytes = read_u32(buf + 14);
379
380 h->slice_num = read_u8(buf + 18);
381 h->slice_bytes = read_u16(buf + 20);
382 h->bos = read_u8(buf + 22);
383 h->header_stream = read_u8(buf + 23);
384 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
385 return -E_FECDEC_EOF;
386 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
387 // h->group_num, h->slice_num, h->slices_per_group);
388 return 1;
389 }
390
391 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
392 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
393 struct filter_node *fn)
394 {
395 struct fecdec_group *fg;
396 int ret, k, n;
397 struct private_fecdec_data *pfd = fn->private_data;
398
399 PARA_CRIT_LOG("sb: %d, len: %d\n", h->slice_bytes, len);
400 if (h->slice_bytes > len) { /* can not use the thing, try to read more */
401 fn->min_iqs = h->slice_bytes + FEC_HEADER_SIZE;
402 return 0;
403 }
404 ret = get_group(h, pfd, &fg);
405 if (ret < 0)
406 return ret;
407 if (!add_slice(buf, fg)) /* group already complete */
408 return 1;
409 if (!group_complete(fg))
410 return 1;
411 /* this slice completed the group */
412 if (pfd->fec)
413 goto decode;
414 /* it's either the first or the second complete group */
415 if (!pfd->first_complete_group) { /* it's the first group */
416 enum fec_group_usability u = group_is_usable(fg, pfd);
417 assert(u != FEC_GROUP_USABLE_SKIP_HEADER);
418 if (u == FEC_GROUP_UNUSABLE) /* forget it */
419 return 1;
420 pfd->first_complete_group = fg; /* remember it */
421 return 1;
422 }
423 /* we have two complete groups, let's go */
424 k = h->data_slices_per_group;
425 n = h->slices_per_group;
426 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
427 ret = fec_new(k, n, &pfd->fec);
428 if (ret < 0)
429 return ret;
430 /* decode and clear the first group */
431 ret = decode_group(pfd->first_complete_group, fn);
432 if (ret < 0)
433 return ret;
434 clear_group(pfd->first_complete_group);
435 pfd->first_complete_group = NULL;
436 decode:
437 ret = decode_group(fg, fn);
438 if (ret < 0)
439 return ret;
440 return 1;
441 }
442
443 static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
444 {
445 int ret;
446 struct fec_header h;
447
448 ret = read_fec_header(buf, len, &h);
449 if (ret <= 0)
450 return ret;
451 if (!h.slice_bytes)
452 return -E_BAD_SLICE_SIZE;
453 if (h.slice_num > h.slices_per_group)
454 return -E_BAD_SLICE_NUM;
455 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
456 &h, fn);
457 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
458 if (ret <= 0)
459 return ret;
460 return FEC_HEADER_SIZE + h.slice_bytes;
461 }
462
463 static void fecdec_close(struct filter_node *fn)
464 {
465 struct private_fecdec_data *pfd = fn->private_data;
466 struct fecdec_group *fg;
467
468 FOR_EACH_FECDEC_GROUP(fg, pfd)
469 clear_group(fg);
470 free(fn->buf);
471 fn->buf = NULL;
472 fec_free(pfd->fec);
473 free(fn->private_data);
474 fn->private_data = NULL;
475 fn->conf = NULL;
476 }
477
478 static void fecdec_post_select(__a_unused struct sched *s, struct task *t)
479 {
480 struct filter_node *fn = container_of(t, struct filter_node, task);
481 struct btr_node *btrn = fn->btrn;
482 int ret;
483 struct fec_header h;
484 char *buf;
485 size_t len;
486
487 next_buffer:
488 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
489 if (ret <= 0)
490 goto out;
491 btr_merge(btrn, fn->min_iqs);
492 len = btr_next_buffer(btrn, &buf);
493 ret = read_fec_header(buf, len, &h);
494 if (ret <= 0)
495 goto out;
496 ret = -E_BAD_SLICE_SIZE;
497 if (!h.slice_bytes)
498 goto out;
499 ret = -E_BAD_SLICE_NUM;
500 if (h.slice_num > h.slices_per_group)
501 goto out;
502 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
503 &h, fn);
504 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
505 if (ret <= 0)
506 goto out;
507 btr_consume(btrn, FEC_HEADER_SIZE + h.slice_bytes);
508 goto next_buffer;
509 out:
510 t->error = ret;
511 if (ret < 0)
512 btr_remove_node(btrn);
513 }
514
515 static void fecdec_open(struct filter_node *fn)
516 {
517 struct private_fecdec_data *pfd;
518 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
519 fn->buf = para_malloc(fn->bufsize);
520 pfd = para_calloc(sizeof(*pfd));
521 fn->private_data = pfd;
522 fn->loaded = 0;
523 fn->min_iqs = FEC_HEADER_SIZE;
524 }
525
526 /**
527 * The init function of the fecdec filter.
528 *
529 * \param f Struct to initialize.
530 */
531 void fecdec_filter_init(struct filter *f)
532 {
533 f->convert = fecdec;
534 f->close = fecdec_close;
535 f->open = fecdec_open;
536 f->pre_select = generic_filter_pre_select;
537 f->post_select = fecdec_post_select;
538 }