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 fg->data = NULL;
114 free(fg->idx);
115 fg->idx = NULL;
116 fg->num_slices = 0;
117 memset(&fg->h, 0, sizeof(struct fec_header));
118 fg->num_received_slices = 0;
119 }
120
121 static int find_group(struct fec_header *h,
122 struct private_fecdec_data *pfd, struct fecdec_group **result)
123 {
124 struct fecdec_group *fg;
125
126 FOR_EACH_FECDEC_GROUP(fg, pfd) {
127 if (fg->h.group_num != h->group_num)
128 continue;
129 if (fg->num_received_slices == 0)
130 goto success;
131 if (fg->h.slices_per_group != h->slices_per_group)
132 return -E_BAD_FEC_HEADER;
133 if (fg->h.data_slices_per_group != h->data_slices_per_group)
134 return -E_BAD_FEC_HEADER;
135 if (fg->h.group_bytes != h->group_bytes)
136 return -E_BAD_FEC_HEADER;
137 success:
138 *result = fg;
139 return 1;
140 }
141 return 0;
142 }
143
144 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
145 {
146 struct fecdec_group *fg;
147
148 FOR_EACH_FECDEC_GROUP(fg, pfd) {
149 if (fg->num_received_slices == 0)
150 return fg;
151 }
152 return NULL;
153 }
154
155 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
156 {
157 struct fecdec_group *fg;
158
159 FOR_EACH_FECDEC_GROUP(fg, pfd) {
160 if (!group_complete(fg))
161 continue;
162 /*
163 * Don't clear the first complete group if it has not yet been
164 * decoded.
165 */
166 if (fg == pfd->first_complete_group)
167 continue;
168 clear_group(fg);
169 return fg;
170 }
171 return NULL;
172 }
173
174 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
175 {
176 struct fecdec_group *fg, *oldest = NULL;
177
178 FOR_EACH_FECDEC_GROUP(fg, pfd) {
179 if (!oldest || oldest->h.group_num > fg->h.group_num)
180 oldest = fg;
181 }
182 if (!group_complete(oldest) && !group_empty(oldest))
183 PARA_WARNING_LOG("Clearing incomplete group %d "
184 "(contains %d slices)\n", oldest->h.group_num,
185 oldest->num_received_slices);
186 if (oldest == pfd->first_complete_group)
187 pfd->first_complete_group = NULL;
188 clear_group(oldest);
189 return oldest;
190 }
191
192 /* returns 1 if the group was found, 0 if not, negative on errors */
193 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
194 struct fecdec_group **result)
195 {
196 struct fecdec_group *fg;
197 int ret = find_group(h, pfd, &fg);
198
199 if (ret < 0)
200 return ret;
201 if (ret > 0) /* found group */
202 goto success;
203 /* group not found */
204 fg = find_unused_group(pfd);
205 if (fg)
206 goto success;
207 fg = try_to_free_group(pfd);
208 if (fg)
209 goto success;
210 fg = free_oldest_group(pfd);
211 ret = 0;
212 success:
213 fg->h = *h;
214 *result = fg;
215 return ret;
216 }
217
218 /*
219 * returns 1 if slice was added, zero otherwise (because the group was already
220 * complete). In any case the number of received slices is being increased by
221 * one.
222 */
223 static int add_slice(char *buf, struct fecdec_group *fg)
224 {
225 int r, slice_num;
226
227 if (group_complete(fg)) {
228 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
229 fg->h.group_num, fg->h.slice_num);
230 fg->num_received_slices++;
231 return 0;
232 }
233 slice_num = fg->h.slice_num;
234 if (fg->num_slices == 0) {
235 fg->num_slices = fg->h.slices_per_group;
236 fg->idx = para_malloc(fg->num_slices * sizeof(int));
237 fg->data = para_malloc(fg->num_slices * sizeof(unsigned char *));
238 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
239 }
240 r = fg->num_received_slices;
241 fg->idx[r] = slice_num;
242 fg->data[r] = para_malloc(fg->h.slice_bytes);
243 memcpy(fg->data[r], buf, fg->h.slice_bytes);
244 fg->num_received_slices++;
245 return 1;
246 }
247
248 enum fec_group_usability {
249 FEC_GROUP_UNUSABLE,
250 FEC_GROUP_USABLE,
251 FEC_GROUP_USABLE_SKIP_HEADER,
252 FEC_GROUP_USABLE_WITH_HEADER
253 };
254
255 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
256 struct private_fecdec_data *pfd)
257 {
258 struct fec_header *h = &fg->h;
259
260 if (!h->header_stream)
261 return FEC_GROUP_USABLE;
262 if (pfd->have_header) {
263 if (h->audio_header_size)
264 return FEC_GROUP_USABLE_SKIP_HEADER;
265 return FEC_GROUP_USABLE;
266 }
267 if (fg->h.bos)
268 return FEC_GROUP_USABLE;
269 if (fg->h.audio_header_size)
270 return FEC_GROUP_USABLE_WITH_HEADER;
271 return FEC_GROUP_UNUSABLE;
272 }
273
274 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
275 {
276 int i, ret, sb = fg->h.slice_bytes;
277 size_t written, need;
278 struct private_fecdec_data *pfd = fn->private_data;
279 enum fec_group_usability u = group_is_usable(fg, pfd);
280
281 if (u == FEC_GROUP_UNUSABLE) {
282 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
283 return 0;
284 }
285 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg->h.group_num,
286 fg->h.data_slices_per_group);
287 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
288 if (ret < 0)
289 return ret;
290 pfd->have_header = 1;
291 i = 0;
292 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
293 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
294 / fg->h.slice_bytes;
295 PARA_DEBUG_LOG("skipping %d header slices\n", i);
296 }
297 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
298 fg->h.group_num, fg->h.group_bytes,
299 fg->h.data_slices_per_group * sb);
300 need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
301 if (need > fn->bufsize) {
302 fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
303 if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
304 return -E_FECDEC_OVERRUN;
305 PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
306 fn->buf = para_realloc(fn->buf, fn->bufsize);
307 }
308 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
309 PARA_INFO_LOG("writing audio file header\n");
310 written = 0;
311 for (i = 0; i < fg->h.data_slices_per_group; i++) {
312 size_t n = sb;
313 if (written >= fg->h.audio_header_size)
314 break;
315 if (sb + written > fg->h.audio_header_size)
316 n = fg->h.audio_header_size - written;
317 memcpy(fn->buf + fn->loaded, fg->data[i], n);
318 fn->loaded += n;
319 written += n;
320 }
321 }
322 written = 0;
323 for (; i < fg->h.data_slices_per_group; i++) {
324 size_t n = sb;
325 if (n + written > fg->h.group_bytes)
326 n = fg->h.group_bytes - written;
327 memcpy(fn->buf + fn->loaded, fg->data[i], n);
328 fn->loaded += n;
329 written += n;
330 }
331 return 0;
332 }
333
334 /**
335 * Read a fec header from a buffer.
336 *
337 * \param buf The buffer to write to.
338 * \param h The fec header to write.
339 */
340 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
341 {
342 uint32_t magic;
343
344 if (len < FEC_HEADER_SIZE)
345 return 0;
346 magic = read_u32(buf);
347 if (magic != FEC_MAGIC)
348 return -E_BAD_FEC_HEADER;
349 h->slices_per_group = read_u8(buf + 4);
350 h->data_slices_per_group = read_u8(buf + 5);
351 h->audio_header_size = read_u32(buf + 6);
352
353 h->group_num = read_u32(buf + 10);
354 h->group_bytes = read_u32(buf + 14);
355
356 h->slice_num = read_u8(buf + 18);
357 h->slice_bytes = read_u16(buf + 20);
358 h->bos = read_u8(buf + 22);
359 h->header_stream = read_u8(buf + 23);
360 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
361 return -E_FECDEC_EOF;
362 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
363 // h->group_num, h->slice_num, h->slices_per_group);
364 return 1;
365 }
366
367 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
368 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
369 struct filter_node *fn)
370 {
371 struct fecdec_group *fg;
372 int ret, k, n;
373 struct private_fecdec_data *pfd = fn->private_data;
374
375 if (h->slice_bytes > len) /* can not use the thing, try to read more */
376 return 0;
377 ret = get_group(h, pfd, &fg);
378 if (ret < 0)
379 return ret;
380 if (!add_slice(buf, fg)) /* group already complete */
381 return 1;
382 if (!group_complete(fg))
383 return 1;
384 /* this slice completed the group */
385 if (pfd->fec)
386 goto decode;
387 /* it's either the first or the second complete group */
388 if (!pfd->first_complete_group) { /* it's the first group */
389 enum fec_group_usability u = group_is_usable(fg, pfd);
390 assert(u != FEC_GROUP_USABLE_SKIP_HEADER);
391 if (u == FEC_GROUP_UNUSABLE) /* forget it */
392 return 1;
393 pfd->first_complete_group = fg; /* remember it */
394 return 1;
395 }
396 /* we have two complete groups, let's go */
397 k = h->data_slices_per_group;
398 n = h->slices_per_group;
399 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
400 ret = fec_new(k, n, &pfd->fec);
401 if (ret < 0)
402 return ret;
403 /* decode and clear the first group */
404 ret = decode_group(pfd->first_complete_group, fn);
405 if (ret < 0)
406 return ret;
407 clear_group(pfd->first_complete_group);
408 pfd->first_complete_group = NULL;
409 decode:
410 ret = decode_group(fg, fn);
411 if (ret < 0)
412 return ret;
413 return 1;
414 }
415
416 static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
417 {
418 int ret;
419 struct fec_header h;
420
421 ret = read_fec_header(buf, len, &h);
422 if (ret <= 0)
423 return ret;
424 if (!h.slice_bytes)
425 return -E_BAD_SLICE_SIZE;
426 if (h.slice_num > h.slices_per_group)
427 return -E_BAD_SLICE_NUM;
428 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
429 &h, fn);
430 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
431 if (ret <= 0)
432 return ret;
433 return FEC_HEADER_SIZE + h.slice_bytes;
434 }
435
436 static void fecdec_close(struct filter_node *fn)
437 {
438 struct private_fecdec_data *pfd = fn->private_data;
439 struct fecdec_group *fg;
440
441 FOR_EACH_FECDEC_GROUP(fg, pfd)
442 clear_group(fg);
443 free(fn->buf);
444 fn->buf = NULL;
445 fec_free(pfd->fec);
446 free(fn->private_data);
447 fn->private_data = NULL;
448 }
449
450 static void fecdec_open(struct filter_node *fn)
451 {
452 struct private_fecdec_data *pfd;
453 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
454 fn->buf = para_malloc(fn->bufsize);
455 pfd = para_calloc(sizeof(*pfd));
456 fn->private_data = pfd;
457 fn->loaded = 0;
458 }
459
460 /**
461 * The init function of the fecdec filter.
462 *
463 * \param f struct to initialize.
464 */
465 void fecdec_filter_init(struct filter *f)
466 {
467 f->convert = fecdec;
468 f->close = fecdec_close;
469 f->open = fecdec_open;
470 }