Merge branch 'maint'
[paraslash.git] / fecdec_filter.c
1 /*
2 * Copyright (C) 2009-2010 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 /** Data read from the header of a slice. */
35 struct fec_header {
36 /** Total number of slices in this group. */
37 uint8_t slices_per_group;
38 /** Number of slices needed to start decoding. */
39 uint8_t data_slices_per_group;
40 /** Size of the ogg vorbis/wma header (zero for mp3, aac). */
41 uint32_t audio_header_size;
42 /** Number of the FEC group this slice belongs to. */
43 uint32_t group_num;
44 /** Size of the data in this FEC group. */
45 uint32_t group_bytes;
46 /** Number of this slice in the group. */
47 uint8_t slice_num;
48 /** Used data bytes of this slice. */
49 uint16_t slice_bytes;
50 /** Non-zero if this group is the beginning of the stream. */
51 uint8_t bos;
52 /** Non-zero if this stream embedds audio headers into fec groups. */
53 uint8_t header_stream;
54 };
55
56 /**
57 * The status of one partially received FEC group.
58 */
59 struct fecdec_group {
60 /** The header read from the last slice. */
61 struct fec_header h;
62 /** How many slices received so far. */
63 int num_received_slices;
64 /** Bitmap of received slices. */
65 uint8_t received_slices[32];
66 /** The size of the \a idx and the \a data arrays below. */
67 int num_slices;
68 /** Array of indices of the received slices. */
69 int *idx;
70 /** Content of the received slices. */
71 unsigned char **data;
72 };
73
74 /**
75 * Data private to the fecdec filter.
76 */
77 struct private_fecdec_data {
78 /** Used by the fec core code. */
79 struct fec_parms *fec;
80 /** Keeps track of what was received so far. */
81 struct fecdec_group groups[NUM_FEC_GROUPS];
82 /** Whether an audio file header was already received. */
83 int have_header;
84 /** Points to the first received group. */
85 struct fecdec_group *first_complete_group;
86 struct btr_pool *btrp;
87 };
88
89 /** Iterate over all fecdec groups. */
90 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
91 (g) < (d)->groups + NUM_FEC_GROUPS; (g)++)
92
93 static int group_complete(struct fecdec_group *fg)
94 {
95 return fg->num_received_slices >= fg->h.data_slices_per_group;
96 }
97
98 static int group_empty(struct fecdec_group *fg)
99 {
100 return fg->num_received_slices == 0;
101 }
102
103 static void clear_group(struct fecdec_group *fg)
104 {
105 int i;
106
107 for (i = 0; i < fg->num_slices; i++)
108 free(fg->data[i]);
109 free(fg->data);
110 free(fg->idx);
111 memset(fg, 0, sizeof(*fg));
112 }
113
114 static int find_group(struct fec_header *h,
115 struct private_fecdec_data *pfd, struct fecdec_group **result)
116 {
117 struct fecdec_group *fg;
118
119 FOR_EACH_FECDEC_GROUP(fg, pfd) {
120 if (fg->h.group_num != h->group_num)
121 continue;
122 if (fg->num_received_slices == 0)
123 goto success;
124 if (fg->h.slices_per_group != h->slices_per_group)
125 return -E_BAD_FEC_HEADER;
126 if (fg->h.data_slices_per_group != h->data_slices_per_group)
127 return -E_BAD_FEC_HEADER;
128 if (fg->h.group_bytes != h->group_bytes)
129 return -E_BAD_FEC_HEADER;
130 success:
131 *result = fg;
132 return 1;
133 }
134 return 0;
135 }
136
137 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
138 {
139 struct fecdec_group *fg;
140
141 FOR_EACH_FECDEC_GROUP(fg, pfd) {
142 if (fg->num_received_slices == 0)
143 return fg;
144 }
145 return NULL;
146 }
147
148 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
149 {
150 struct fecdec_group *fg;
151
152 FOR_EACH_FECDEC_GROUP(fg, pfd) {
153 if (!group_complete(fg))
154 continue;
155 /*
156 * Don't clear the first complete group if it has not yet been
157 * decoded.
158 */
159 if (fg == pfd->first_complete_group)
160 continue;
161 clear_group(fg);
162 return fg;
163 }
164 return NULL;
165 }
166
167 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
168 {
169 struct fecdec_group *fg, *oldest = NULL;
170
171 FOR_EACH_FECDEC_GROUP(fg, pfd) {
172 if (!oldest || oldest->h.group_num > fg->h.group_num)
173 oldest = fg;
174 }
175 if (!group_complete(oldest) && !group_empty(oldest))
176 PARA_WARNING_LOG("Clearing incomplete group %d "
177 "(contains %d slices)\n", oldest->h.group_num,
178 oldest->num_received_slices);
179 if (oldest == pfd->first_complete_group)
180 pfd->first_complete_group = NULL;
181 clear_group(oldest);
182 return oldest;
183 }
184
185 /* returns 1 if the group was found, 0 if not, negative on errors */
186 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
187 struct fecdec_group **result)
188 {
189 struct fecdec_group *fg;
190 int ret = find_group(h, pfd, &fg);
191
192 if (ret < 0)
193 return ret;
194 if (ret > 0) /* found group */
195 goto success;
196 /* group not found */
197 fg = find_unused_group(pfd);
198 if (fg)
199 goto success;
200 fg = try_to_free_group(pfd);
201 if (fg)
202 goto success;
203 fg = free_oldest_group(pfd);
204 ret = 0;
205 success:
206 fg->h = *h;
207 *result = fg;
208 return ret;
209 }
210
211 static bool test_and_set_slice_bit(struct fecdec_group *fg, uint8_t slice_num)
212 {
213 uint8_t *p = fg->received_slices + slice_num / 8, old = *p;
214
215 *p |= 1 << (slice_num % 8);
216 return old == *p;
217 }
218
219 /*
220 * returns 1 if slice was added, zero otherwise (because the group was already
221 * complete or a slice has been received twice).
222 */
223 static int add_slice(char *buf, struct fecdec_group *fg)
224 {
225 int r;
226 uint8_t slice_num = fg->h.slice_num;
227
228 if (group_complete(fg)) {
229 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
230 fg->h.group_num, slice_num);
231 return 0;
232 }
233 if (fg->num_slices == 0) {
234 fg->num_slices = fg->h.slices_per_group;
235 fg->idx = para_malloc(fg->num_slices * sizeof(int));
236 fg->data = para_calloc(fg->num_slices * sizeof(unsigned char *));
237 }
238 r = fg->num_received_slices;
239 /* Check if we already have this slice. */
240 if (test_and_set_slice_bit(fg, slice_num)) {
241 PARA_INFO_LOG("ignoring duplicate slice %d:%d\n", fg->h.group_num,
242 slice_num);
243 return 0;
244 }
245 fg->idx[r] = slice_num;
246 fg->data[r] = para_malloc(fg->h.slice_bytes);
247 memcpy(fg->data[r], buf, fg->h.slice_bytes);
248 fg->num_received_slices++;
249 return 1;
250 }
251
252 /**
253 * The different states of a complete FEC group.
254 *
255 * Even if a FEC group has been received successfully, it probably can not be
256 * used right away because some streams (ogg, wma) need to receive an audio
257 * file header before decoding can start.
258 */
259 enum fec_group_usability {
260 /** Drop the group (because we did not receive the header yet). */
261 FEC_GROUP_UNUSABLE,
262 /** Use all data in the group. */
263 FEC_GROUP_USABLE,
264 /** Use the group, but drop its audio file header. */
265 FEC_GROUP_USABLE_SKIP_HEADER,
266 /** Use the group, including its header. */
267 FEC_GROUP_USABLE_WITH_HEADER
268 };
269
270 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
271 struct private_fecdec_data *pfd)
272 {
273 struct fec_header *h = &fg->h;
274
275 if (!h->header_stream)
276 return FEC_GROUP_USABLE;
277 if (pfd->have_header) {
278 if (h->audio_header_size)
279 return FEC_GROUP_USABLE_SKIP_HEADER;
280 return FEC_GROUP_USABLE;
281 }
282 if (fg->h.bos)
283 return FEC_GROUP_USABLE;
284 if (fg->h.audio_header_size)
285 return FEC_GROUP_USABLE_WITH_HEADER;
286 return FEC_GROUP_UNUSABLE;
287 }
288
289 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
290 {
291 int i, ret, sb = fg->h.slice_bytes;
292 size_t written, need;
293 struct private_fecdec_data *pfd = fn->private_data;
294 enum fec_group_usability u = group_is_usable(fg, pfd);
295 char *buf = NULL, *p;
296
297 if (u == FEC_GROUP_UNUSABLE) {
298 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
299 return 0;
300 }
301 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg->h.group_num,
302 fg->h.data_slices_per_group);
303 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
304 if (ret < 0)
305 return ret;
306 pfd->have_header = 1;
307 i = 0;
308 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
309 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
310 / fg->h.slice_bytes;
311 PARA_DEBUG_LOG("skipping %d header slices\n", i);
312 }
313 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
314 fg->h.group_num, fg->h.group_bytes,
315 fg->h.data_slices_per_group * sb);
316 need = (fg->h.data_slices_per_group - i) * sb;
317 if (need > btr_pool_unused(pfd->btrp))
318 return -E_FECDEC_OVERRUN;
319 btr_pool_get_buffer(pfd->btrp, &buf);
320 p = buf;
321 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
322 PARA_INFO_LOG("writing audio file header\n");
323 written = 0;
324 for (i = 0; i < fg->h.data_slices_per_group; i++) {
325 size_t n = sb;
326 if (written >= fg->h.audio_header_size)
327 break;
328 if (sb + written > fg->h.audio_header_size)
329 n = fg->h.audio_header_size - written;
330 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
331 written += n;
332 }
333 p += written;
334 }
335 written = 0;
336 for (; i < fg->h.data_slices_per_group; i++) {
337 size_t n = sb;
338 if (n + written > fg->h.group_bytes)
339 n = fg->h.group_bytes - written;
340 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
341 written += n;
342 }
343 p += written;
344 return 0;
345 }
346
347 /**
348 * Read a fec header from a buffer.
349 *
350 * \param buf The buffer to write to.
351 * \param h The fec header to write.
352 */
353 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
354 {
355 uint32_t magic;
356
357 if (len < FEC_HEADER_SIZE)
358 return 0;
359 magic = read_u32(buf);
360 if (magic != FEC_MAGIC)
361 return -E_BAD_FEC_HEADER;
362 h->slices_per_group = read_u8(buf + 4);
363 h->data_slices_per_group = read_u8(buf + 5);
364 h->audio_header_size = read_u32(buf + 6);
365
366 h->group_num = read_u32(buf + 10);
367 h->group_bytes = read_u32(buf + 14);
368
369 h->slice_num = read_u8(buf + 18);
370 h->slice_bytes = read_u16(buf + 20);
371 h->bos = read_u8(buf + 22);
372 h->header_stream = read_u8(buf + 23);
373 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
374 return -E_FECDEC_EOF;
375 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
376 // h->group_num, h->slice_num, h->slices_per_group);
377 return 1;
378 }
379
380 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
381 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
382 struct filter_node *fn)
383 {
384 struct fecdec_group *fg;
385 int ret, k, n;
386 struct private_fecdec_data *pfd = fn->private_data;
387
388 if (h->slice_bytes > len) { /* can not use the thing, try to read more */
389 fn->min_iqs = h->slice_bytes + FEC_HEADER_SIZE;
390 return 0;
391 }
392 ret = get_group(h, pfd, &fg);
393 if (ret < 0)
394 return ret;
395 if (!add_slice(buf, fg)) /* group already complete */
396 return 1;
397 if (!group_complete(fg))
398 return 1;
399 /* this slice completed the group */
400 if (pfd->fec)
401 goto decode;
402 /* it's either the first or the second complete group */
403 if (!pfd->first_complete_group) { /* it's the first group */
404 enum fec_group_usability u = group_is_usable(fg, pfd);
405 assert(u != FEC_GROUP_USABLE_SKIP_HEADER);
406 if (u == FEC_GROUP_UNUSABLE) /* forget it */
407 return 1;
408 pfd->first_complete_group = fg; /* remember it */
409 return 1;
410 }
411 /* we have two complete groups, let's go */
412 k = h->data_slices_per_group;
413 n = h->slices_per_group;
414 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
415 ret = fec_new(k, n, &pfd->fec);
416 if (ret < 0)
417 return ret;
418 pfd->btrp = btr_pool_new("fecdec", 20 * k * h->slice_bytes);
419 /* decode and clear the first group */
420 ret = decode_group(pfd->first_complete_group, fn);
421 if (ret < 0)
422 return ret;
423 clear_group(pfd->first_complete_group);
424 pfd->first_complete_group = NULL;
425 decode:
426 ret = decode_group(fg, fn);
427 if (ret < 0)
428 return ret;
429 return 1;
430 }
431
432 static void fecdec_close(struct filter_node *fn)
433 {
434 struct private_fecdec_data *pfd = fn->private_data;
435 struct fecdec_group *fg;
436
437 FOR_EACH_FECDEC_GROUP(fg, pfd)
438 clear_group(fg);
439 fec_free(pfd->fec);
440 btr_pool_free(pfd->btrp);
441 free(fn->private_data);
442 fn->private_data = NULL;
443 }
444
445 static void fecdec_post_select(__a_unused struct sched *s, struct task *t)
446 {
447 struct filter_node *fn = container_of(t, struct filter_node, task);
448 struct btr_node *btrn = fn->btrn;
449 int ret;
450 struct fec_header h;
451 char *buf;
452 size_t len;
453
454 next_buffer:
455 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
456 if (ret <= 0)
457 goto out;
458 btr_merge(btrn, fn->min_iqs);
459 len = btr_next_buffer(btrn, &buf);
460 ret = read_fec_header(buf, len, &h);
461 if (ret <= 0)
462 goto out;
463 ret = -E_BAD_SLICE_SIZE;
464 if (!h.slice_bytes)
465 goto out;
466 ret = -E_BAD_SLICE_NUM;
467 if (h.slice_num > h.slices_per_group)
468 goto out;
469 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
470 &h, fn);
471 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
472 if (ret <= 0)
473 goto out;
474 btr_consume(btrn, FEC_HEADER_SIZE + h.slice_bytes);
475 goto next_buffer;
476 out:
477 t->error = ret;
478 if (ret < 0)
479 btr_remove_node(btrn);
480 }
481
482 static void fecdec_open(struct filter_node *fn)
483 {
484 struct private_fecdec_data *pfd;
485 pfd = para_calloc(sizeof(*pfd));
486 fn->private_data = pfd;
487 fn->min_iqs = FEC_HEADER_SIZE;
488 }
489
490 /**
491 * The init function of the fecdec filter.
492 *
493 * \param f Struct to initialize.
494 */
495 void fecdec_filter_init(struct filter *f)
496 {
497 f->close = fecdec_close;
498 f->open = fecdec_open;
499 f->pre_select = generic_filter_pre_select;
500 f->post_select = fecdec_post_select;
501 }