client: Fix return value check for sb_received().
[paraslash.git] / fecdec_filter.c
1 /*
2 * Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>
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
11 #include "para.h"
12 #include "error.h"
13 #include "list.h"
14 #include "sched.h"
15 #include "ggo.h"
16 #include "buffer_tree.h"
17 #include "filter.h"
18 #include "string.h"
19 #include "portable_io.h"
20 #include "fec.h"
21 #include "fd.h"
22
23 /**
24 * How many FEC groups to store in memory.
25 *
26 * Packet reordering requires to keep more than one FEC group in memory because
27 * slices belonging to the next FEC group may arrive before the current FEC group
28 * is complete.
29 */
30 #define NUM_FEC_GROUPS 3
31
32 /** Data read from the header of a slice. */
33 struct fec_header {
34 /** Total number of slices in this group. */
35 uint8_t slices_per_group;
36 /** Number of slices needed to start decoding. */
37 uint8_t data_slices_per_group;
38 /** Size of the ogg vorbis/wma header (zero for mp3, aac). */
39 uint32_t audio_header_size;
40 /** Number of the FEC group this slice belongs to. */
41 uint32_t group_num;
42 /** Size of the data in this FEC group. */
43 uint32_t group_bytes;
44 /** Number of this slice in the group. */
45 uint8_t slice_num;
46 /** Used data bytes of this slice. */
47 uint16_t slice_bytes;
48 /** Non-zero if this group is the beginning of the stream. */
49 uint8_t bos;
50 /** Non-zero if this stream embeds audio headers into fec groups. */
51 uint8_t header_stream;
52 };
53
54 /**
55 * The status of one partially received FEC group.
56 */
57 struct fecdec_group {
58 /** The header read from the last slice. */
59 struct fec_header h;
60 /** How many slices received so far. */
61 int num_received_slices;
62 /** Bitmap of received slices. */
63 uint8_t received_slices[32];
64 /** The size of the \a idx and the \a data arrays below. */
65 int num_slices;
66 /** Array of indices of the received slices. */
67 int *idx;
68 /** Content of the received slices. */
69 unsigned char **data;
70 };
71
72 /**
73 * Data private to the fecdec filter.
74 */
75 struct private_fecdec_data {
76 /** Used by the fec core code. */
77 struct fec_parms *fec;
78 /** Keeps track of what was received so far. */
79 struct fecdec_group groups[NUM_FEC_GROUPS];
80 /** Whether an audio file header was already received. */
81 int have_header;
82 /** Points to the first received group. */
83 struct fecdec_group *first_complete_group;
84 struct btr_pool *btrp;
85 };
86
87 /** Iterate over all fecdec groups. */
88 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
89 (g) < (d)->groups + NUM_FEC_GROUPS; (g)++)
90
91 static int group_complete(struct fecdec_group *fg)
92 {
93 return fg->num_received_slices >= fg->h.data_slices_per_group;
94 }
95
96 static int group_empty(struct fecdec_group *fg)
97 {
98 return fg->num_received_slices == 0;
99 }
100
101 static void clear_group(struct fecdec_group *fg)
102 {
103 int i;
104
105 for (i = 0; i < fg->num_slices; i++)
106 free(fg->data[i]);
107 free(fg->data);
108 free(fg->idx);
109 memset(fg, 0, sizeof(*fg));
110 }
111
112 static int find_group(struct fec_header *h,
113 struct private_fecdec_data *pfd, struct fecdec_group **result)
114 {
115 struct fecdec_group *fg;
116
117 FOR_EACH_FECDEC_GROUP(fg, pfd) {
118 if (fg->h.group_num != h->group_num)
119 continue;
120 if (fg->num_received_slices == 0)
121 goto success;
122 if (fg->h.slices_per_group != h->slices_per_group)
123 return -E_BAD_FEC_HEADER;
124 if (fg->h.data_slices_per_group != h->data_slices_per_group)
125 return -E_BAD_FEC_HEADER;
126 if (fg->h.group_bytes != h->group_bytes)
127 return -E_BAD_FEC_HEADER;
128 success:
129 *result = fg;
130 return 1;
131 }
132 return 0;
133 }
134
135 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
136 {
137 struct fecdec_group *fg;
138
139 FOR_EACH_FECDEC_GROUP(fg, pfd) {
140 if (fg->num_received_slices == 0)
141 return fg;
142 }
143 return NULL;
144 }
145
146 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
147 {
148 struct fecdec_group *fg;
149
150 FOR_EACH_FECDEC_GROUP(fg, pfd) {
151 if (!group_complete(fg))
152 continue;
153 /*
154 * Don't clear the first complete group if it has not yet been
155 * decoded.
156 */
157 if (fg == pfd->first_complete_group)
158 continue;
159 clear_group(fg);
160 return fg;
161 }
162 return NULL;
163 }
164
165 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
166 {
167 struct fecdec_group *fg, *oldest = NULL;
168
169 FOR_EACH_FECDEC_GROUP(fg, pfd) {
170 if (!oldest || oldest->h.group_num > fg->h.group_num)
171 oldest = fg;
172 }
173 if (!group_complete(oldest) && !group_empty(oldest))
174 PARA_WARNING_LOG("Clearing incomplete group %d "
175 "(contains %d slices)\n", oldest->h.group_num,
176 oldest->num_received_slices);
177 if (oldest == pfd->first_complete_group)
178 pfd->first_complete_group = NULL;
179 clear_group(oldest);
180 return oldest;
181 }
182
183 /* returns 1 if the group was found, 0 if not, negative on errors */
184 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
185 struct fecdec_group **result)
186 {
187 struct fecdec_group *fg;
188 int ret = find_group(h, pfd, &fg);
189
190 if (ret < 0)
191 return ret;
192 if (ret > 0) /* found group */
193 goto success;
194 /* group not found */
195 fg = find_unused_group(pfd);
196 if (fg)
197 goto success;
198 fg = try_to_free_group(pfd);
199 if (fg)
200 goto success;
201 fg = free_oldest_group(pfd);
202 ret = 0;
203 success:
204 fg->h = *h;
205 *result = fg;
206 return ret;
207 }
208
209 static bool test_and_set_slice_bit(struct fecdec_group *fg, uint8_t slice_num)
210 {
211 uint8_t *p = fg->received_slices + slice_num / 8, old = *p;
212
213 *p |= 1 << (slice_num % 8);
214 return old == *p;
215 }
216
217 /*
218 * returns 1 if slice was added, zero otherwise (because the group was already
219 * complete or a slice has been received twice).
220 */
221 static int add_slice(char *buf, struct fecdec_group *fg)
222 {
223 int r;
224 uint8_t slice_num = fg->h.slice_num;
225
226 if (group_complete(fg)) {
227 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
228 fg->h.group_num, slice_num);
229 return 0;
230 }
231 if (fg->num_slices == 0) {
232 fg->num_slices = fg->h.slices_per_group;
233 fg->idx = para_malloc(fg->num_slices * sizeof(int));
234 fg->data = para_calloc(fg->num_slices * sizeof(unsigned char *));
235 }
236 r = fg->num_received_slices;
237 /* Check if we already have this slice. */
238 if (test_and_set_slice_bit(fg, slice_num)) {
239 PARA_INFO_LOG("ignoring duplicate slice %d:%d\n", fg->h.group_num,
240 slice_num);
241 return 0;
242 }
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;
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 = DIV_ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes);
308 PARA_DEBUG_LOG("skipping %d header slices\n", i);
309 }
310 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
311 fg->h.group_num, fg->h.group_bytes,
312 fg->h.data_slices_per_group * sb);
313 need = (fg->h.data_slices_per_group - i) * sb;
314 if (need > btr_pool_unused(pfd->btrp))
315 return -E_FECDEC_OVERRUN;
316 btr_pool_get_buffer(pfd->btrp, &buf);
317 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
318 PARA_INFO_LOG("writing audio file header\n");
319 written = 0;
320 for (i = 0; i < fg->h.data_slices_per_group; i++) {
321 size_t n = sb;
322 if (written >= fg->h.audio_header_size)
323 break;
324 if (sb + written > fg->h.audio_header_size)
325 n = fg->h.audio_header_size - written;
326 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
327 written += n;
328 }
329 }
330 written = 0;
331 for (; i < fg->h.data_slices_per_group; i++) {
332 size_t n = sb;
333 if (n + written > fg->h.group_bytes)
334 n = fg->h.group_bytes - written;
335 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
336 written += n;
337 }
338 return 0;
339 }
340
341 /**
342 * Read a fec header from a buffer.
343 *
344 * \param buf The buffer to write to.
345 * \param h The fec header to write.
346 */
347 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
348 {
349 uint32_t magic;
350
351 if (len < FEC_HEADER_SIZE)
352 return 0;
353 magic = read_u32(buf);
354 if (magic != FEC_MAGIC)
355 return -E_BAD_FEC_HEADER;
356 h->slices_per_group = read_u8(buf + 4);
357 h->data_slices_per_group = read_u8(buf + 5);
358 h->audio_header_size = read_u32(buf + 6);
359
360 h->group_num = read_u32(buf + 10);
361 h->group_bytes = read_u32(buf + 14);
362
363 h->slice_num = read_u8(buf + 18);
364 h->slice_bytes = read_u16(buf + 20);
365 h->bos = read_u8(buf + 22);
366 h->header_stream = read_u8(buf + 23);
367 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
368 return -E_FECDEC_EOF;
369 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
370 // h->group_num, h->slice_num, h->slices_per_group);
371 return 1;
372 }
373
374 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
375 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
376 struct filter_node *fn)
377 {
378 struct fecdec_group *fg;
379 int ret, k, n;
380 struct private_fecdec_data *pfd = fn->private_data;
381
382 if (h->slice_bytes > len) { /* can not use the thing, try to read more */
383 fn->min_iqs = h->slice_bytes + FEC_HEADER_SIZE;
384 return 0;
385 }
386 ret = get_group(h, pfd, &fg);
387 if (ret < 0)
388 return ret;
389 if (!add_slice(buf, fg)) /* group already complete */
390 return 1;
391 if (!group_complete(fg))
392 return 1;
393 /* this slice completed the group */
394 if (pfd->fec)
395 goto decode;
396 /* it's either the first or the second complete group */
397 if (!pfd->first_complete_group) { /* it's the first group */
398 enum fec_group_usability u = group_is_usable(fg, pfd);
399 assert(u != FEC_GROUP_USABLE_SKIP_HEADER);
400 if (u == FEC_GROUP_UNUSABLE) /* forget it */
401 return 1;
402 pfd->first_complete_group = fg; /* remember it */
403 return 1;
404 }
405 /* we have two complete groups, let's go */
406 k = h->data_slices_per_group;
407 n = h->slices_per_group;
408 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
409 ret = fec_new(k, n, &pfd->fec);
410 if (ret < 0)
411 return ret;
412 pfd->btrp = btr_pool_new("fecdec", 128 * 1024);
413 /* decode and clear the first group */
414 ret = decode_group(pfd->first_complete_group, fn);
415 if (ret < 0)
416 return ret;
417 clear_group(pfd->first_complete_group);
418 pfd->first_complete_group = NULL;
419 decode:
420 ret = decode_group(fg, fn);
421 if (ret < 0)
422 return ret;
423 return 1;
424 }
425
426 static void fecdec_close(struct filter_node *fn)
427 {
428 struct private_fecdec_data *pfd = fn->private_data;
429 struct fecdec_group *fg;
430
431 FOR_EACH_FECDEC_GROUP(fg, pfd)
432 clear_group(fg);
433 fec_free(pfd->fec);
434 btr_pool_free(pfd->btrp);
435 free(fn->private_data);
436 fn->private_data = NULL;
437 }
438
439 static int fecdec_post_select(__a_unused struct sched *s, void *context)
440 {
441 struct filter_node *fn = context;
442 struct btr_node *btrn = fn->btrn;
443 int ret;
444 struct fec_header h;
445 char *buf;
446 size_t len;
447
448 next_buffer:
449 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
450 if (ret <= 0)
451 goto out;
452 btr_merge(btrn, fn->min_iqs);
453 len = btr_next_buffer(btrn, &buf);
454 ret = read_fec_header(buf, len, &h);
455 if (ret <= 0)
456 goto out;
457 ret = -E_BAD_SLICE_SIZE;
458 if (!h.slice_bytes)
459 goto out;
460 ret = -E_BAD_SLICE_NUM;
461 if (h.slice_num > h.slices_per_group)
462 goto out;
463 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
464 &h, fn);
465 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
466 if (ret <= 0)
467 goto out;
468 btr_consume(btrn, FEC_HEADER_SIZE + h.slice_bytes);
469 goto next_buffer;
470 out:
471 if (ret < 0)
472 btr_remove_node(&fn->btrn);
473 return ret;
474 }
475
476 static void fecdec_open(struct filter_node *fn)
477 {
478 struct private_fecdec_data *pfd;
479 pfd = para_calloc(sizeof(*pfd));
480 fn->private_data = pfd;
481 fn->min_iqs = FEC_HEADER_SIZE;
482 }
483
484 /**
485 * The init function of the fecdec filter.
486 *
487 * \param f Struct to initialize.
488 */
489 void fecdec_filter_init(struct filter *f)
490 {
491 f->close = fecdec_close;
492 f->open = fecdec_open;
493 f->pre_select = generic_filter_pre_select;
494 f->post_select = fecdec_post_select;
495 }