oggdec: Fix a thinko in post_select().
[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 /** 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 /** 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 fg->data[i] = NULL;
108 fg->idx[i] = -1;
109 }
110 free(fg->data);
111 fg->data = NULL;
112 free(fg->idx);
113 fg->idx = NULL;
114 fg->num_slices = 0;
115 memset(&fg->h, 0, sizeof(struct fec_header));
116 fg->num_received_slices = 0;
117 }
118
119 static int find_group(struct fec_header *h,
120 struct private_fecdec_data *pfd, struct fecdec_group **result)
121 {
122 struct fecdec_group *fg;
123
124 FOR_EACH_FECDEC_GROUP(fg, pfd) {
125 if (fg->h.group_num != h->group_num)
126 continue;
127 if (fg->num_received_slices == 0)
128 goto success;
129 if (fg->h.slices_per_group != h->slices_per_group)
130 return -E_BAD_FEC_HEADER;
131 if (fg->h.data_slices_per_group != h->data_slices_per_group)
132 return -E_BAD_FEC_HEADER;
133 if (fg->h.group_bytes != h->group_bytes)
134 return -E_BAD_FEC_HEADER;
135 success:
136 *result = fg;
137 return 1;
138 }
139 return 0;
140 }
141
142 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
143 {
144 struct fecdec_group *fg;
145
146 FOR_EACH_FECDEC_GROUP(fg, pfd) {
147 if (fg->num_received_slices == 0)
148 return fg;
149 }
150 return NULL;
151 }
152
153 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
154 {
155 struct fecdec_group *fg;
156
157 FOR_EACH_FECDEC_GROUP(fg, pfd) {
158 if (!group_complete(fg))
159 continue;
160 /*
161 * Don't clear the first complete group if it has not yet been
162 * decoded.
163 */
164 if (fg == pfd->first_complete_group)
165 continue;
166 clear_group(fg);
167 return fg;
168 }
169 return NULL;
170 }
171
172 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
173 {
174 struct fecdec_group *fg, *oldest = NULL;
175
176 FOR_EACH_FECDEC_GROUP(fg, pfd) {
177 if (!oldest || oldest->h.group_num > fg->h.group_num)
178 oldest = fg;
179 }
180 if (!group_complete(oldest) && !group_empty(oldest))
181 PARA_WARNING_LOG("Clearing incomplete group %d "
182 "(contains %d slices)\n", oldest->h.group_num,
183 oldest->num_received_slices);
184 if (oldest == pfd->first_complete_group)
185 pfd->first_complete_group = NULL;
186 clear_group(oldest);
187 return oldest;
188 }
189
190 /* returns 1 if the group was found, 0 if not, negative on errors */
191 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
192 struct fecdec_group **result)
193 {
194 struct fecdec_group *fg;
195 int ret = find_group(h, pfd, &fg);
196
197 if (ret < 0)
198 return ret;
199 if (ret > 0) /* found group */
200 goto success;
201 /* group not found */
202 fg = find_unused_group(pfd);
203 if (fg)
204 goto success;
205 fg = try_to_free_group(pfd);
206 if (fg)
207 goto success;
208 fg = free_oldest_group(pfd);
209 ret = 0;
210 success:
211 fg->h = *h;
212 *result = fg;
213 return ret;
214 }
215
216 /*
217 * returns 1 if slice was added, zero otherwise (because the group was already
218 * complete). In any case the number of received slices is being increased by
219 * one.
220 */
221 static int add_slice(char *buf, struct fecdec_group *fg)
222 {
223 int r, slice_num;
224
225 if (group_complete(fg)) {
226 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
227 fg->h.group_num, fg->h.slice_num);
228 fg->num_received_slices++;
229 return 0;
230 }
231 slice_num = fg->h.slice_num;
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_malloc(fg->num_slices * sizeof(unsigned char *));
236 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
237 }
238 r = fg->num_received_slices;
239 fg->idx[r] = slice_num;
240 fg->data[r] = para_malloc(fg->h.slice_bytes);
241 memcpy(fg->data[r], buf, fg->h.slice_bytes);
242 fg->num_received_slices++;
243 return 1;
244 }
245
246 /**
247 * The different states of a complete FEC group.
248 *
249 * Even if a FEC group has been received successfully, it probably can not be
250 * used right away because some streams (ogg, wma) need to receive an audio
251 * file header before decoding can start.
252 */
253 enum fec_group_usability {
254 /** Drop the group (because we did not receive the header yet). */
255 FEC_GROUP_UNUSABLE,
256 /** Use all data in the group. */
257 FEC_GROUP_USABLE,
258 /** Use the group, but drop its audio file header. */
259 FEC_GROUP_USABLE_SKIP_HEADER,
260 /** Use the group, including its header. */
261 FEC_GROUP_USABLE_WITH_HEADER
262 };
263
264 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
265 struct private_fecdec_data *pfd)
266 {
267 struct fec_header *h = &fg->h;
268
269 if (!h->header_stream)
270 return FEC_GROUP_USABLE;
271 if (pfd->have_header) {
272 if (h->audio_header_size)
273 return FEC_GROUP_USABLE_SKIP_HEADER;
274 return FEC_GROUP_USABLE;
275 }
276 if (fg->h.bos)
277 return FEC_GROUP_USABLE;
278 if (fg->h.audio_header_size)
279 return FEC_GROUP_USABLE_WITH_HEADER;
280 return FEC_GROUP_UNUSABLE;
281 }
282
283 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
284 {
285 int i, ret, sb = fg->h.slice_bytes;
286 size_t written, need;
287 struct private_fecdec_data *pfd = fn->private_data;
288 enum fec_group_usability u = group_is_usable(fg, pfd);
289 char *buf = NULL, *p;
290
291 if (u == FEC_GROUP_UNUSABLE) {
292 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
293 return 0;
294 }
295 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg->h.group_num,
296 fg->h.data_slices_per_group);
297 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
298 if (ret < 0)
299 return ret;
300 pfd->have_header = 1;
301 i = 0;
302 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
303 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
304 / fg->h.slice_bytes;
305 PARA_DEBUG_LOG("skipping %d header slices\n", i);
306 }
307 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
308 fg->h.group_num, fg->h.group_bytes,
309 fg->h.data_slices_per_group * sb);
310 need = (fg->h.data_slices_per_group - i) * sb;
311 if (need > btr_pool_unused(pfd->btrp))
312 return -E_FECDEC_OVERRUN;
313 btr_pool_get_buffer(pfd->btrp, &buf);
314 p = buf;
315 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
316 PARA_INFO_LOG("writing audio file header\n");
317 written = 0;
318 for (i = 0; i < fg->h.data_slices_per_group; i++) {
319 size_t n = sb;
320 if (written >= fg->h.audio_header_size)
321 break;
322 if (sb + written > fg->h.audio_header_size)
323 n = fg->h.audio_header_size - written;
324 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
325 written += n;
326 }
327 p += written;
328 }
329 written = 0;
330 for (; i < fg->h.data_slices_per_group; i++) {
331 size_t n = sb;
332 if (n + written > fg->h.group_bytes)
333 n = fg->h.group_bytes - written;
334 btr_copy(fg->data[i], n, pfd->btrp, fn->btrn);
335 written += n;
336 }
337 p += written;
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", 20 * k * h->slice_bytes);
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 void fecdec_post_select(__a_unused struct sched *s, struct task *t)
440 {
441 struct filter_node *fn = container_of(t, struct filter_node, task);
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 t->error = ret;
472 if (ret < 0)
473 btr_remove_node(btrn);
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 }