Merge branch 'maint'
[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
11 #include <dirent.h>
12 #include "para.h"
13 #include "error.h"
14 #include "list.h"
15 #include "sched.h"
16 #include "ggo.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 /** Default size of the output buffer of the fecdec filter. */
33 #define FECDEC_DEFAULT_OUTBUF_SIZE (3 * 1024)
34 /** Maximal size of the output buffer of the fecdec filter. */
35 #define FECDEC_MAX_OUTBUF_SIZE (1024 * 1024)
36
37 /** Data read from the header of a slice. */
38 struct fec_header {
39 /** Total number of slices in this group. */
40 uint8_t slices_per_group;
41 /** Number of slices needed to start decoding. */
42 uint8_t data_slices_per_group;
43 /** Size of the ogg vorbis header (zero for mp3, aac). */
44 uint32_t audio_header_size;
45 /** Number of the FEC group this slice belongs to. */
46 uint32_t group_num;
47 /** Size of the data in this FEC group. */
48 uint32_t group_bytes;
49 /** Number of this slice in the group. */
50 uint8_t slice_num;
51 /** Used data bytes of this slice. */
52 uint16_t slice_bytes;
53 /** Non-zero if this group is the beginning of the stream. */
54 uint8_t bos;
55 /** Non-zero if this stream embedds audio headers into fec groups. */
56 uint8_t header_stream;
57 };
58
59 /**
60 * The status of one partially received FEC group.
61 */
62 struct fecdec_group {
63 /** The header read from the last slice. */
64 struct fec_header h;
65 /** How many slices received so far. */
66 int num_received_slices;
67 /** The size of the \a idx and the \a data arrays below. */
68 int num_slices;
69 /** Array of indices of the received slices. */
70 int *idx;
71 /** Content of the received slices. */
72 unsigned char **data;
73 };
74
75 /**
76 * Data private to the fecdec filter.
77 */
78 struct private_fecdec_data {
79 /** Used by the fec core code. */
80 struct fec_parms *fec;
81 /** Keeps track of what was received so far. */
82 struct fecdec_group groups[NUM_FEC_GROUPS];
83 /** Whether an audio file header was already received. */
84 int have_header;
85 /** Points to the first received group. */
86 struct fecdec_group *first_complete_group;
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 fg->data[i] = NULL;
110 fg->idx[i] = -1;
111 }
112 free(fg->data);
113 free(fg->idx);
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 enum fec_group_usability {
247 FEC_GROUP_UNUSABLE,
248 FEC_GROUP_USABLE,
249 FEC_GROUP_USABLE_SKIP_HEADER,
250 FEC_GROUP_USABLE_WITH_HEADER
251 };
252
253 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
254 struct private_fecdec_data *pfd)
255 {
256 struct fec_header *h = &fg->h;
257
258 if (!h->header_stream)
259 return FEC_GROUP_USABLE;
260 if (pfd->have_header) {
261 if (h->audio_header_size)
262 return FEC_GROUP_USABLE_SKIP_HEADER;
263 return FEC_GROUP_USABLE;
264 }
265 if (fg->h.bos)
266 return FEC_GROUP_USABLE;
267 if (fg->h.audio_header_size)
268 return FEC_GROUP_USABLE_WITH_HEADER;
269 return FEC_GROUP_UNUSABLE;
270 }
271
272 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
273 {
274 int i, ret, sb = fg->h.slice_bytes;
275 size_t written, need;
276 struct private_fecdec_data *pfd = fn->private_data;
277 enum fec_group_usability u = group_is_usable(fg, pfd);
278
279 if (u == FEC_GROUP_UNUSABLE) {
280 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
281 return 0;
282 }
283 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg->h.group_num,
284 fg->h.data_slices_per_group);
285 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
286 if (ret < 0)
287 return ret;
288 pfd->have_header = 1;
289 i = 0;
290 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
291 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
292 / fg->h.slice_bytes;
293 PARA_DEBUG_LOG("skipping %d header slices\n", i);
294 }
295 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
296 fg->h.group_num, fg->h.group_bytes,
297 fg->h.data_slices_per_group * sb);
298 need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
299 if (need > fn->bufsize) {
300 fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
301 if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
302 return -E_FECDEC_OVERRUN;
303 PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
304 fn->buf = para_realloc(fn->buf, fn->bufsize);
305 }
306 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
307 PARA_INFO_LOG("writing audio file header\n");
308 written = 0;
309 for (i = 0; i < fg->h.data_slices_per_group; i++) {
310 size_t n = sb;
311 if (written >= fg->h.audio_header_size)
312 break;
313 if (sb + written > fg->h.audio_header_size)
314 n = fg->h.audio_header_size - written;
315 memcpy(fn->buf + fn->loaded, fg->data[i], n);
316 fn->loaded += n;
317 written += n;
318 }
319 }
320 written = 0;
321 for (; i < fg->h.data_slices_per_group; i++) {
322 size_t n = sb;
323 if (n + written > fg->h.group_bytes)
324 n = fg->h.group_bytes - written;
325 memcpy(fn->buf + fn->loaded, fg->data[i], n);
326 fn->loaded += n;
327 written += n;
328 }
329 return 0;
330 }
331
332 /**
333 * Read a fec header from a buffer.
334 *
335 * \param buf The buffer to write to.
336 * \param h The fec header to write.
337 */
338 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
339 {
340 uint32_t magic;
341
342 if (len < FEC_HEADER_SIZE)
343 return 0;
344 magic = read_u32(buf);
345 if (magic != FEC_MAGIC)
346 return -E_BAD_FEC_HEADER;
347 h->slices_per_group = read_u8(buf + 4);
348 h->data_slices_per_group = read_u8(buf + 5);
349 h->audio_header_size = read_u32(buf + 6);
350
351 h->group_num = read_u32(buf + 10);
352 h->group_bytes = read_u32(buf + 14);
353
354 h->slice_num = read_u8(buf + 18);
355 h->slice_bytes = read_u16(buf + 20);
356 h->bos = read_u8(buf + 22);
357 h->header_stream = read_u8(buf + 23);
358 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
359 return -E_FECDEC_EOF;
360 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
361 // h->group_num, h->slice_num, h->slices_per_group);
362 return 1;
363 }
364
365 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
366 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
367 struct filter_node *fn)
368 {
369 struct fecdec_group *fg;
370 int ret, k, n;
371 struct private_fecdec_data *pfd = fn->private_data;
372
373 if (h->slice_bytes > len) /* can not use the thing, try to read more */
374 return 0;
375 ret = get_group(h, pfd, &fg);
376 if (ret < 0)
377 return ret;
378 if (!add_slice(buf, fg)) /* group already complete */
379 return 1;
380 if (!group_complete(fg))
381 return 1;
382 /* this slice completed the group */
383 if (pfd->fec)
384 goto decode;
385 /* it's either the first or the second complete group */
386 if (!pfd->first_complete_group) { /* it's the first group */
387 enum fec_group_usability u = group_is_usable(fg, pfd);
388 assert(u != FEC_GROUP_USABLE_SKIP_HEADER);
389 if (u == FEC_GROUP_UNUSABLE) /* forget it */
390 return 1;
391 pfd->first_complete_group = fg; /* remember it */
392 return 1;
393 }
394 /* we have two complete groups, let's go */
395 k = h->data_slices_per_group;
396 n = h->slices_per_group;
397 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
398 ret = fec_new(k, n, &pfd->fec);
399 if (ret < 0)
400 return ret;
401 /* decode and clear the first group */
402 ret = decode_group(pfd->first_complete_group, fn);
403 if (ret < 0)
404 return ret;
405 clear_group(pfd->first_complete_group);
406 pfd->first_complete_group = NULL;
407 decode:
408 ret = decode_group(fg, fn);
409 if (ret < 0)
410 return ret;
411 return 1;
412 }
413
414 static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
415 {
416 int ret;
417 struct fec_header h;
418
419 ret = read_fec_header(buf, len, &h);
420 if (ret <= 0)
421 return ret;
422 if (!h.slice_bytes)
423 return -E_BAD_SLICE_SIZE;
424 if (h.slice_num > h.slices_per_group)
425 return -E_BAD_SLICE_NUM;
426 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
427 &h, fn);
428 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
429 if (ret <= 0)
430 return ret;
431 return FEC_HEADER_SIZE + h.slice_bytes;
432 }
433
434 static void fecdec_close(struct filter_node *fn)
435 {
436 struct private_fecdec_data *pfd = fn->private_data;
437 struct fecdec_group *fg;
438
439 FOR_EACH_FECDEC_GROUP(fg, pfd)
440 clear_group(fg);
441 free(fn->buf);
442 fn->buf = NULL;
443 fec_free(pfd->fec);
444 free(fn->private_data);
445 fn->private_data = NULL;
446 }
447
448 static void fecdec_open(struct filter_node *fn)
449 {
450 struct private_fecdec_data *pfd;
451 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
452 fn->buf = para_malloc(fn->bufsize);
453 pfd = para_calloc(sizeof(*pfd));
454 fn->private_data = pfd;
455 fn->loaded = 0;
456 }
457
458 /**
459 * The init function of the fecdec filter.
460 *
461 * \param f struct to initialize.
462 */
463 void fecdec_filter_init(struct filter *f)
464 {
465 f->convert = fecdec;
466 f->close = fecdec_close;
467 f->open = fecdec_open;
468 }