fd35d5f5d6a278a615c34e02c9c096d775330c0a
[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 struct btr_pool *btrp;
90 };
91
92 /** Iterate over all fecdec groups. */
93 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
94 (g) < (d)->groups + NUM_FEC_GROUPS; (g)++)
95
96 static int group_complete(struct fecdec_group *fg)
97 {
98 return fg->num_received_slices >= fg->h.data_slices_per_group;
99 }
100
101 static int group_empty(struct fecdec_group *fg)
102 {
103 return fg->num_received_slices == 0;
104 }
105
106 static void clear_group(struct fecdec_group *fg)
107 {
108 int i;
109
110 for (i = 0; i < fg->num_slices; i++) {
111 free(fg->data[i]);
112 fg->data[i] = NULL;
113 fg->idx[i] = -1;
114 }
115 free(fg->data);
116 fg->data = NULL;
117 free(fg->idx);
118 fg->idx = NULL;
119 fg->num_slices = 0;
120 memset(&fg->h, 0, sizeof(struct fec_header));
121 fg->num_received_slices = 0;
122 }
123
124 static int find_group(struct fec_header *h,
125 struct private_fecdec_data *pfd, struct fecdec_group **result)
126 {
127 struct fecdec_group *fg;
128
129 FOR_EACH_FECDEC_GROUP(fg, pfd) {
130 if (fg->h.group_num != h->group_num)
131 continue;
132 if (fg->num_received_slices == 0)
133 goto success;
134 if (fg->h.slices_per_group != h->slices_per_group)
135 return -E_BAD_FEC_HEADER;
136 if (fg->h.data_slices_per_group != h->data_slices_per_group)
137 return -E_BAD_FEC_HEADER;
138 if (fg->h.group_bytes != h->group_bytes)
139 return -E_BAD_FEC_HEADER;
140 success:
141 *result = fg;
142 return 1;
143 }
144 return 0;
145 }
146
147 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
148 {
149 struct fecdec_group *fg;
150
151 FOR_EACH_FECDEC_GROUP(fg, pfd) {
152 if (fg->num_received_slices == 0)
153 return fg;
154 }
155 return NULL;
156 }
157
158 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
159 {
160 struct fecdec_group *fg;
161
162 FOR_EACH_FECDEC_GROUP(fg, pfd) {
163 if (!group_complete(fg))
164 continue;
165 /*
166 * Don't clear the first complete group if it has not yet been
167 * decoded.
168 */
169 if (fg == pfd->first_complete_group)
170 continue;
171 clear_group(fg);
172 return fg;
173 }
174 return NULL;
175 }
176
177 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
178 {
179 struct fecdec_group *fg, *oldest = NULL;
180
181 FOR_EACH_FECDEC_GROUP(fg, pfd) {
182 if (!oldest || oldest->h.group_num > fg->h.group_num)
183 oldest = fg;
184 }
185 if (!group_complete(oldest) && !group_empty(oldest))
186 PARA_WARNING_LOG("Clearing incomplete group %d "
187 "(contains %d slices)\n", oldest->h.group_num,
188 oldest->num_received_slices);
189 if (oldest == pfd->first_complete_group)
190 pfd->first_complete_group = NULL;
191 clear_group(oldest);
192 return oldest;
193 }
194
195 /* returns 1 if the group was found, 0 if not, negative on errors */
196 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
197 struct fecdec_group **result)
198 {
199 struct fecdec_group *fg;
200 int ret = find_group(h, pfd, &fg);
201
202 if (ret < 0)
203 return ret;
204 if (ret > 0) /* found group */
205 goto success;
206 /* group not found */
207 fg = find_unused_group(pfd);
208 if (fg)
209 goto success;
210 fg = try_to_free_group(pfd);
211 if (fg)
212 goto success;
213 fg = free_oldest_group(pfd);
214 ret = 0;
215 success:
216 fg->h = *h;
217 *result = fg;
218 return ret;
219 }
220
221 /*
222 * returns 1 if slice was added, zero otherwise (because the group was already
223 * complete). In any case the number of received slices is being increased by
224 * one.
225 */
226 static int add_slice(char *buf, struct fecdec_group *fg)
227 {
228 int r, slice_num;
229
230 if (group_complete(fg)) {
231 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
232 fg->h.group_num, fg->h.slice_num);
233 fg->num_received_slices++;
234 return 0;
235 }
236 slice_num = fg->h.slice_num;
237 if (fg->num_slices == 0) {
238 fg->num_slices = fg->h.slices_per_group;
239 fg->idx = para_malloc(fg->num_slices * sizeof(int));
240 fg->data = para_malloc(fg->num_slices * sizeof(unsigned char *));
241 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
242 }
243 r = fg->num_received_slices;
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, *p;
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 = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
309 / fg->h.slice_bytes;
310 PARA_DEBUG_LOG("skipping %d header slices\n", i);
311 }
312 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
313 fg->h.group_num, fg->h.group_bytes,
314 fg->h.data_slices_per_group * sb);
315 need = (fg->h.data_slices_per_group - i) * sb;
316 if (need > btr_pool_unused(pfd->btrp))
317 return -E_FECDEC_OVERRUN;
318 btr_pool_get_buffer(pfd->btrp, &buf);
319 p = buf;
320 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
321 PARA_INFO_LOG("writing audio file header\n");
322 written = 0;
323 for (i = 0; i < fg->h.data_slices_per_group; i++) {
324 size_t n = sb;
325 if (written >= fg->h.audio_header_size)
326 break;
327 if (sb + written > fg->h.audio_header_size)
328 n = fg->h.audio_header_size - written;
329 if (fn->btrn)
330 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
331 else
332 memcpy(p + written, fg->data[i], n);
333 fn->loaded += n;
334 written += n;
335 }
336 p += written;
337 }
338 written = 0;
339 for (; i < fg->h.data_slices_per_group; i++) {
340 size_t n = sb;
341 if (n + written > fg->h.group_bytes)
342 n = fg->h.group_bytes - written;
343 if (fn->btrn)
344 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
345 else
346 memcpy(p + written, fg->data[i], n);
347 fn->loaded += n;
348 written += n;
349 }
350 p += written;
351 return 0;
352 }
353
354 /**
355 * Read a fec header from a buffer.
356 *
357 * \param buf The buffer to write to.
358 * \param h The fec header to write.
359 */
360 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
361 {
362 uint32_t magic;
363
364 if (len < FEC_HEADER_SIZE)
365 return 0;
366 magic = read_u32(buf);
367 if (magic != FEC_MAGIC)
368 return -E_BAD_FEC_HEADER;
369 h->slices_per_group = read_u8(buf + 4);
370 h->data_slices_per_group = read_u8(buf + 5);
371 h->audio_header_size = read_u32(buf + 6);
372
373 h->group_num = read_u32(buf + 10);
374 h->group_bytes = read_u32(buf + 14);
375
376 h->slice_num = read_u8(buf + 18);
377 h->slice_bytes = read_u16(buf + 20);
378 h->bos = read_u8(buf + 22);
379 h->header_stream = read_u8(buf + 23);
380 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
381 return -E_FECDEC_EOF;
382 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
383 // h->group_num, h->slice_num, h->slices_per_group);
384 return 1;
385 }
386
387 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
388 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
389 struct filter_node *fn)
390 {
391 struct fecdec_group *fg;
392 int ret, k, n;
393 struct private_fecdec_data *pfd = fn->private_data;
394
395 if (h->slice_bytes > len) { /* can not use the thing, try to read more */
396 fn->min_iqs = h->slice_bytes + FEC_HEADER_SIZE;
397 return 0;
398 }
399 ret = get_group(h, pfd, &fg);
400 if (ret < 0)
401 return ret;
402 if (!add_slice(buf, fg)) /* group already complete */
403 return 1;
404 if (!group_complete(fg))
405 return 1;
406 /* this slice completed the group */
407 if (pfd->fec)
408 goto decode;
409 /* it's either the first or the second complete group */
410 if (!pfd->first_complete_group) { /* it's the first group */
411 enum fec_group_usability u = group_is_usable(fg, pfd);
412 assert(u != FEC_GROUP_USABLE_SKIP_HEADER);
413 if (u == FEC_GROUP_UNUSABLE) /* forget it */
414 return 1;
415 pfd->first_complete_group = fg; /* remember it */
416 return 1;
417 }
418 /* we have two complete groups, let's go */
419 k = h->data_slices_per_group;
420 n = h->slices_per_group;
421 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
422 ret = fec_new(k, n, &pfd->fec);
423 if (ret < 0)
424 return ret;
425 pfd->btrp = btr_pool_new("fecdec", 20 * k * h->slice_bytes);
426 /* decode and clear the first group */
427 ret = decode_group(pfd->first_complete_group, fn);
428 if (ret < 0)
429 return ret;
430 clear_group(pfd->first_complete_group);
431 pfd->first_complete_group = NULL;
432 decode:
433 ret = decode_group(fg, fn);
434 if (ret < 0)
435 return ret;
436 return 1;
437 }
438
439 static void fecdec_close(struct filter_node *fn)
440 {
441 struct private_fecdec_data *pfd = fn->private_data;
442 struct fecdec_group *fg;
443
444 FOR_EACH_FECDEC_GROUP(fg, pfd)
445 clear_group(fg);
446 free(fn->buf);
447 fn->buf = NULL;
448 fec_free(pfd->fec);
449 free(fn->private_data);
450 fn->private_data = NULL;
451 fn->conf = NULL;
452 }
453
454 static void fecdec_post_select(__a_unused struct sched *s, struct task *t)
455 {
456 struct filter_node *fn = container_of(t, struct filter_node, task);
457 struct btr_node *btrn = fn->btrn;
458 int ret;
459 struct fec_header h;
460 char *buf;
461 size_t len;
462
463 next_buffer:
464 ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
465 if (ret <= 0)
466 goto out;
467 btr_merge(btrn, fn->min_iqs);
468 len = btr_next_buffer(btrn, &buf);
469 ret = read_fec_header(buf, len, &h);
470 if (ret <= 0)
471 goto out;
472 ret = -E_BAD_SLICE_SIZE;
473 if (!h.slice_bytes)
474 goto out;
475 ret = -E_BAD_SLICE_NUM;
476 if (h.slice_num > h.slices_per_group)
477 goto out;
478 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
479 &h, fn);
480 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
481 if (ret <= 0)
482 goto out;
483 btr_consume(btrn, FEC_HEADER_SIZE + h.slice_bytes);
484 goto next_buffer;
485 out:
486 t->error = ret;
487 if (ret < 0)
488 btr_remove_node(btrn);
489 }
490
491 static void fecdec_open(struct filter_node *fn)
492 {
493 struct private_fecdec_data *pfd;
494 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
495 fn->buf = para_malloc(fn->bufsize);
496 pfd = para_calloc(sizeof(*pfd));
497 fn->private_data = pfd;
498 fn->loaded = 0;
499 fn->min_iqs = FEC_HEADER_SIZE;
500 }
501
502 /**
503 * The init function of the fecdec filter.
504 *
505 * \param f Struct to initialize.
506 */
507 void fecdec_filter_init(struct filter *f)
508 {
509 f->close = fecdec_close;
510 f->open = fecdec_open;
511 f->pre_select = generic_filter_pre_select;
512 f->post_select = fecdec_post_select;
513 }