Merge branch 't/crypto'
[paraslash.git] / fecdec_filter.c
1 /*
2 * Copyright (C) 2009-2011 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 "para.h"
13 #include "error.h"
14 #include "list.h"
15 #include "sched.h"
16 #include "ggo.h"
17 #include "buffer_tree.h"
18 #include "filter.h"
19 #include "string.h"
20 #include "portable_io.h"
21 #include "fec.h"
22 #include "fd.h"
23
24 /**
25 * How many FEC groups to store in memory.
26 *
27 * Packet reordering requires to keep more than one FEC group in memory because
28 * slices belonging to the next FEC group may arrive before the current FEC group
29 * is complete.
30 */
31 #define NUM_FEC_GROUPS 3
32
33 /** Data read from the header of a slice. */
34 struct fec_header {
35 /** Total number of slices in this group. */
36 uint8_t slices_per_group;
37 /** Number of slices needed to start decoding. */
38 uint8_t data_slices_per_group;
39 /** Size of the ogg vorbis/wma header (zero for mp3, aac). */
40 uint32_t audio_header_size;
41 /** Number of the FEC group this slice belongs to. */
42 uint32_t group_num;
43 /** Size of the data in this FEC group. */
44 uint32_t group_bytes;
45 /** Number of this slice in the group. */
46 uint8_t slice_num;
47 /** Used data bytes of this slice. */
48 uint16_t slice_bytes;
49 /** Non-zero if this group is the beginning of the stream. */
50 uint8_t bos;
51 /** Non-zero if this stream embedds audio headers into fec groups. */
52 uint8_t header_stream;
53 };
54
55 /**
56 * The status of one partially received FEC group.
57 */
58 struct fecdec_group {
59 /** The header read from the last slice. */
60 struct fec_header h;
61 /** How many slices received so far. */
62 int num_received_slices;
63 /** Bitmap of received slices. */
64 uint8_t received_slices[32];
65 /** The size of the \a idx and the \a data arrays below. */
66 int num_slices;
67 /** Array of indices of the received slices. */
68 int *idx;
69 /** Content of the received slices. */
70 unsigned char **data;
71 };
72
73 /**
74 * Data private to the fecdec filter.
75 */
76 struct private_fecdec_data {
77 /** Used by the fec core code. */
78 struct fec_parms *fec;
79 /** Keeps track of what was received so far. */
80 struct fecdec_group groups[NUM_FEC_GROUPS];
81 /** Whether an audio file header was already received. */
82 int have_header;
83 /** Points to the first received group. */
84 struct fecdec_group *first_complete_group;
85 struct btr_pool *btrp;
86 };
87
88 /** Iterate over all fecdec groups. */
89 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
90 (g) < (d)->groups + NUM_FEC_GROUPS; (g)++)
91
92 static int group_complete(struct fecdec_group *fg)
93 {
94 return fg->num_received_slices >= fg->h.data_slices_per_group;
95 }
96
97 static int group_empty(struct fecdec_group *fg)
98 {
99 return fg->num_received_slices == 0;
100 }
101
102 static void clear_group(struct fecdec_group *fg)
103 {
104 int i;
105
106 for (i = 0; i < fg->num_slices; i++)
107 free(fg->data[i]);
108 free(fg->data);
109 free(fg->idx);
110 memset(fg, 0, sizeof(*fg));
111 }
112
113 static int find_group(struct fec_header *h,
114 struct private_fecdec_data *pfd, struct fecdec_group **result)
115 {
116 struct fecdec_group *fg;
117
118 FOR_EACH_FECDEC_GROUP(fg, pfd) {
119 if (fg->h.group_num != h->group_num)
120 continue;
121 if (fg->num_received_slices == 0)
122 goto success;
123 if (fg->h.slices_per_group != h->slices_per_group)
124 return -E_BAD_FEC_HEADER;
125 if (fg->h.data_slices_per_group != h->data_slices_per_group)
126 return -E_BAD_FEC_HEADER;
127 if (fg->h.group_bytes != h->group_bytes)
128 return -E_BAD_FEC_HEADER;
129 success:
130 *result = fg;
131 return 1;
132 }
133 return 0;
134 }
135
136 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
137 {
138 struct fecdec_group *fg;
139
140 FOR_EACH_FECDEC_GROUP(fg, pfd) {
141 if (fg->num_received_slices == 0)
142 return fg;
143 }
144 return NULL;
145 }
146
147 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
148 {
149 struct fecdec_group *fg;
150
151 FOR_EACH_FECDEC_GROUP(fg, pfd) {
152 if (!group_complete(fg))
153 continue;
154 /*
155 * Don't clear the first complete group if it has not yet been
156 * decoded.
157 */
158 if (fg == pfd->first_complete_group)
159 continue;
160 clear_group(fg);
161 return fg;
162 }
163 return NULL;
164 }
165
166 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
167 {
168 struct fecdec_group *fg, *oldest = NULL;
169
170 FOR_EACH_FECDEC_GROUP(fg, pfd) {
171 if (!oldest || oldest->h.group_num > fg->h.group_num)
172 oldest = fg;
173 }
174 if (!group_complete(oldest) && !group_empty(oldest))
175 PARA_WARNING_LOG("Clearing incomplete group %d "
176 "(contains %d slices)\n", oldest->h.group_num,
177 oldest->num_received_slices);
178 if (oldest == pfd->first_complete_group)
179 pfd->first_complete_group = NULL;
180 clear_group(oldest);
181 return oldest;
182 }
183
184 /* returns 1 if the group was found, 0 if not, negative on errors */
185 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
186 struct fecdec_group **result)
187 {
188 struct fecdec_group *fg;
189 int ret = find_group(h, pfd, &fg);
190
191 if (ret < 0)
192 return ret;
193 if (ret > 0) /* found group */
194 goto success;
195 /* group not found */
196 fg = find_unused_group(pfd);
197 if (fg)
198 goto success;
199 fg = try_to_free_group(pfd);
200 if (fg)
201 goto success;
202 fg = free_oldest_group(pfd);
203 ret = 0;
204 success:
205 fg->h = *h;
206 *result = fg;
207 return ret;
208 }
209
210 static bool test_and_set_slice_bit(struct fecdec_group *fg, uint8_t slice_num)
211 {
212 uint8_t *p = fg->received_slices + slice_num / 8, old = *p;
213
214 *p |= 1 << (slice_num % 8);
215 return old == *p;
216 }
217
218 /*
219 * returns 1 if slice was added, zero otherwise (because the group was already
220 * complete or a slice has been received twice).
221 */
222 static int add_slice(char *buf, struct fecdec_group *fg)
223 {
224 int r;
225 uint8_t slice_num = fg->h.slice_num;
226
227 if (group_complete(fg)) {
228 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
229 fg->h.group_num, slice_num);
230 return 0;
231 }
232 if (fg->num_slices == 0) {
233 fg->num_slices = fg->h.slices_per_group;
234 fg->idx = para_malloc(fg->num_slices * sizeof(int));
235 fg->data = para_calloc(fg->num_slices * sizeof(unsigned char *));
236 }
237 r = fg->num_received_slices;
238 /* Check if we already have this slice. */
239 if (test_and_set_slice_bit(fg, slice_num)) {
240 PARA_INFO_LOG("ignoring duplicate slice %d:%d\n", fg->h.group_num,
241 slice_num);
242 return 0;
243 }
244 fg->idx[r] = slice_num;
245 fg->data[r] = para_malloc(fg->h.slice_bytes);
246 memcpy(fg->data[r], buf, fg->h.slice_bytes);
247 fg->num_received_slices++;
248 return 1;
249 }
250
251 /**
252 * The different states of a complete FEC group.
253 *
254 * Even if a FEC group has been received successfully, it probably can not be
255 * used right away because some streams (ogg, wma) need to receive an audio
256 * file header before decoding can start.
257 */
258 enum fec_group_usability {
259 /** Drop the group (because we did not receive the header yet). */
260 FEC_GROUP_UNUSABLE,
261 /** Use all data in the group. */
262 FEC_GROUP_USABLE,
263 /** Use the group, but drop its audio file header. */
264 FEC_GROUP_USABLE_SKIP_HEADER,
265 /** Use the group, including its header. */
266 FEC_GROUP_USABLE_WITH_HEADER
267 };
268
269 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
270 struct private_fecdec_data *pfd)
271 {
272 struct fec_header *h = &fg->h;
273
274 if (!h->header_stream)
275 return FEC_GROUP_USABLE;
276 if (pfd->have_header) {
277 if (h->audio_header_size)
278 return FEC_GROUP_USABLE_SKIP_HEADER;
279 return FEC_GROUP_USABLE;
280 }
281 if (fg->h.bos)
282 return FEC_GROUP_USABLE;
283 if (fg->h.audio_header_size)
284 return FEC_GROUP_USABLE_WITH_HEADER;
285 return FEC_GROUP_UNUSABLE;
286 }
287
288 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
289 {
290 int i, ret, sb = fg->h.slice_bytes;
291 size_t written, need;
292 struct private_fecdec_data *pfd = fn->private_data;
293 enum fec_group_usability u = group_is_usable(fg, pfd);
294 char *buf = NULL;
295
296 if (u == FEC_GROUP_UNUSABLE) {
297 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
298 return 0;
299 }
300 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg->h.group_num,
301 fg->h.data_slices_per_group);
302 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
303 if (ret < 0)
304 return ret;
305 pfd->have_header = 1;
306 i = 0;
307 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
308 i = DIV_ROUND_UP(fg->h.audio_header_size, 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 = (fg->h.data_slices_per_group - i) * sb;
315 if (need > btr_pool_unused(pfd->btrp))
316 return -E_FECDEC_OVERRUN;
317 btr_pool_get_buffer(pfd->btrp, &buf);
318 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
319 PARA_INFO_LOG("writing audio file header\n");
320 written = 0;
321 for (i = 0; i < fg->h.data_slices_per_group; i++) {
322 size_t n = sb;
323 if (written >= fg->h.audio_header_size)
324 break;
325 if (sb + written > fg->h.audio_header_size)
326 n = fg->h.audio_header_size - written;
327 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
328 written += n;
329 }
330 }
331 written = 0;
332 for (; i < fg->h.data_slices_per_group; i++) {
333 size_t n = sb;
334 if (n + written > fg->h.group_bytes)
335 n = fg->h.group_bytes - written;
336 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
337 written += n;
338 }
339 return 0;
340 }
341
342 /**
343 * Read a fec header from a buffer.
344 *
345 * \param buf The buffer to write to.
346 * \param h The fec header to write.
347 */
348 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
349 {
350 uint32_t magic;
351
352 if (len < FEC_HEADER_SIZE)
353 return 0;
354 magic = read_u32(buf);
355 if (magic != FEC_MAGIC)
356 return -E_BAD_FEC_HEADER;
357 h->slices_per_group = read_u8(buf + 4);
358 h->data_slices_per_group = read_u8(buf + 5);
359 h->audio_header_size = read_u32(buf + 6);
360
361 h->group_num = read_u32(buf + 10);
362 h->group_bytes = read_u32(buf + 14);
363
364 h->slice_num = read_u8(buf + 18);
365 h->slice_bytes = read_u16(buf + 20);
366 h->bos = read_u8(buf + 22);
367 h->header_stream = read_u8(buf + 23);
368 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
369 return -E_FECDEC_EOF;
370 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
371 // h->group_num, h->slice_num, h->slices_per_group);
372 return 1;
373 }
374
375 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
376 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
377 struct filter_node *fn)
378 {
379 struct fecdec_group *fg;
380 int ret, k, n;
381 struct private_fecdec_data *pfd = fn->private_data;
382
383 if (h->slice_bytes > len) { /* can not use the thing, try to read more */
384 fn->min_iqs = h->slice_bytes + FEC_HEADER_SIZE;
385 return 0;
386 }
387 ret = get_group(h, pfd, &fg);
388 if (ret < 0)
389 return ret;
390 if (!add_slice(buf, fg)) /* group already complete */
391 return 1;
392 if (!group_complete(fg))
393 return 1;
394 /* this slice completed the group */
395 if (pfd->fec)
396 goto decode;
397 /* it's either the first or the second complete group */
398 if (!pfd->first_complete_group) { /* it's the first group */
399 enum fec_group_usability u = group_is_usable(fg, pfd);
400 assert(u != FEC_GROUP_USABLE_SKIP_HEADER);
401 if (u == FEC_GROUP_UNUSABLE) /* forget it */
402 return 1;
403 pfd->first_complete_group = fg; /* remember it */
404 return 1;
405 }
406 /* we have two complete groups, let's go */
407 k = h->data_slices_per_group;
408 n = h->slices_per_group;
409 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
410 ret = fec_new(k, n, &pfd->fec);
411 if (ret < 0)
412 return ret;
413 pfd->btrp = btr_pool_new("fecdec", 64 * 1024);
414 /* decode and clear the first group */
415 ret = decode_group(pfd->first_complete_group, fn);
416 if (ret < 0)
417 return ret;
418 clear_group(pfd->first_complete_group);
419 pfd->first_complete_group = NULL;
420 decode:
421 ret = decode_group(fg, fn);
422 if (ret < 0)
423 return ret;
424 return 1;
425 }
426
427 static void fecdec_close(struct filter_node *fn)
428 {
429 struct private_fecdec_data *pfd = fn->private_data;
430 struct fecdec_group *fg;
431
432 FOR_EACH_FECDEC_GROUP(fg, pfd)
433 clear_group(fg);
434 fec_free(pfd->fec);
435 btr_pool_free(pfd->btrp);
436 free(fn->private_data);
437 fn->private_data = NULL;
438 }
439
440 static void fecdec_post_select(__a_unused struct sched *s, struct task *t)
441 {
442 struct filter_node *fn = container_of(t, struct filter_node, task);
443 struct btr_node *btrn = fn->btrn;
444 int ret;
445 struct fec_header h;
446 char *buf;
447 size_t len;
448
449 next_buffer:
450 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
451 if (ret <= 0)
452 goto out;
453 btr_merge(btrn, fn->min_iqs);
454 len = btr_next_buffer(btrn, &buf);
455 ret = read_fec_header(buf, len, &h);
456 if (ret <= 0)
457 goto out;
458 ret = -E_BAD_SLICE_SIZE;
459 if (!h.slice_bytes)
460 goto out;
461 ret = -E_BAD_SLICE_NUM;
462 if (h.slice_num > h.slices_per_group)
463 goto out;
464 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
465 &h, fn);
466 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
467 if (ret <= 0)
468 goto out;
469 btr_consume(btrn, FEC_HEADER_SIZE + h.slice_bytes);
470 goto next_buffer;
471 out:
472 t->error = ret;
473 if (ret < 0)
474 btr_remove_node(btrn);
475 }
476
477 static void fecdec_open(struct filter_node *fn)
478 {
479 struct private_fecdec_data *pfd;
480 pfd = para_calloc(sizeof(*pfd));
481 fn->private_data = pfd;
482 fn->min_iqs = FEC_HEADER_SIZE;
483 }
484
485 /**
486 * The init function of the fecdec filter.
487 *
488 * \param f Struct to initialize.
489 */
490 void fecdec_filter_init(struct filter *f)
491 {
492 f->close = fecdec_close;
493 f->open = fecdec_open;
494 f->pre_select = generic_filter_pre_select;
495 f->post_select = fecdec_post_select;
496 }