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 * The fecdec filter defers decoding of the first group until the first slice
77 * of the next group was received. This avoids buffer underruns in subsequent
78 * filters of the filter chain.
79 */
80 enum group_completion_status {
81 /** No complete group received so far. */
82 GCS_NO_COMPLETE_GROUP,
83 /** First group received, but not yet decoded. */
84 GCS_FIRST_GROUP_COMPLETE,
85 /** At least one complete group decoded. */
86 GCS_FIRST_GROUP_DECODED,
87 };
88
89 /**
90 * Data private to the fecdec filter.
91 */
92 struct private_fecdec_data {
93 /** Used by the fec core code. */
94 struct fec_parms *fec;
95 /** Keeps track of what was received so far. */
96 struct fecdec_group groups[NUM_FEC_GROUPS];
97 /** Whether an audio file header was already received. */
98 int have_header;
99 /** See \ref group_completion_status. */
100 unsigned completion_status;
101 /** Points to the first received group. */
102 struct fecdec_group *first_complete_group;
103 };
104
105 /** Iterate over all fecdec groups. */
106 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
107 (g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
108
109 static int group_complete(struct fecdec_group *fg)
110 {
111 return fg->num_received_slices >= fg->h.data_slices_per_group;
112 }
113
114 static int group_empty(struct fecdec_group *fg)
115 {
116 return fg->num_received_slices == 0;
117 }
118
119 static void clear_group(struct fecdec_group *fg)
120 {
121 int i;
122
123 for (i = 0; i < fg->num_slices; i++) {
124 free(fg->data[i]);
125 fg->data[i] = NULL;
126 fg->idx[i] = -1;
127 }
128 free(fg->data);
129 free(fg->idx);
130 fg->num_slices = 0;
131 memset(&fg->h, 0, sizeof(struct fec_header));
132 fg->num_received_slices = 0;
133 }
134
135 static int find_group(struct fec_header *h,
136 struct private_fecdec_data *pfd, struct fecdec_group **result)
137 {
138 struct fecdec_group *fg;
139
140 FOR_EACH_FECDEC_GROUP(fg, pfd) {
141 if (fg->h.group_num != h->group_num)
142 continue;
143 if (fg->num_received_slices == 0)
144 goto success;
145 if (fg->h.slices_per_group != h->slices_per_group)
146 return -E_BAD_FEC_HEADER;
147 if (fg->h.data_slices_per_group != h->data_slices_per_group)
148 return -E_BAD_FEC_HEADER;
149 if (fg->h.group_bytes != h->group_bytes)
150 return -E_BAD_FEC_HEADER;
151 success:
152 *result = fg;
153 return 1;
154 }
155 return 0;
156 }
157
158 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
159 {
160 struct fecdec_group *fg;
161
162 FOR_EACH_FECDEC_GROUP(fg, pfd) {
163 if (fg->num_received_slices == 0)
164 return fg;
165 }
166 return NULL;
167 }
168
169 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
170 {
171 struct fecdec_group *fg;
172
173 FOR_EACH_FECDEC_GROUP(fg, pfd) {
174 if (!group_complete(fg))
175 continue;
176 /*
177 * Don't clear the first complete group if it has not yet been
178 * decoded.
179 */
180 if (pfd->completion_status == GCS_FIRST_GROUP_COMPLETE
181 && pfd->first_complete_group == fg)
182 continue;
183 clear_group(fg);
184 return fg;
185 }
186 return NULL;
187 }
188
189 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
190 {
191 struct fecdec_group *fg, *oldest = NULL;
192
193 FOR_EACH_FECDEC_GROUP(fg, pfd) {
194 if (!oldest || oldest->h.group_num > fg->h.group_num)
195 oldest = fg;
196 }
197 if (!group_complete(oldest) && !group_empty(oldest))
198 PARA_WARNING_LOG("Clearing incomplete group %d "
199 "(contains %d slices)\n", oldest->h.group_num,
200 oldest->num_received_slices);
201 assert(pfd->completion_status != GCS_FIRST_GROUP_COMPLETE
202 || oldest != pfd->first_complete_group);
203 clear_group(oldest);
204 return oldest;
205 }
206
207 /* returns 1 if the group was found, 0 if not, negative on errors */
208 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
209 struct fecdec_group **result)
210 {
211 struct fecdec_group *fg;
212 int ret = find_group(h, pfd, &fg);
213
214 if (ret < 0)
215 return ret;
216 if (ret > 0) /* found group */
217 goto success;
218 /* group not found */
219 fg = find_unused_group(pfd);
220 if (fg)
221 goto success;
222 fg = try_to_free_group(pfd);
223 if (fg)
224 goto success;
225 fg = free_oldest_group(pfd);
226 ret = 0;
227 success:
228 fg->h = *h;
229 *result = fg;
230 return ret;
231 }
232
233 /*
234 * returns 1 if slice was added, zero otherwise (because the group was already
235 * complete). In any case the number of received slices is being increased by
236 * one.
237 */
238 static int add_slice(char *buf, struct fecdec_group *fg)
239 {
240 int r, slice_num;
241
242 if (group_complete(fg)) {
243 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
244 fg->h.group_num, fg->h.slice_num);
245 fg->num_received_slices++;
246 return 0;
247 }
248 slice_num = fg->h.slice_num;
249 if (fg->num_slices == 0) {
250 fg->num_slices = fg->h.slices_per_group;
251 fg->idx = para_malloc(fg->num_slices * sizeof(int));
252 fg->data = para_malloc(fg->num_slices * sizeof(unsigned char *));
253 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
254 }
255 r = fg->num_received_slices;
256 fg->idx[r] = slice_num;
257 fg->data[r] = para_malloc(fg->h.slice_bytes);
258 memcpy(fg->data[r], buf, fg->h.slice_bytes);
259 fg->num_received_slices++;
260 return 1;
261 }
262
263 enum fec_group_usability {
264 FEC_GROUP_UNUSABLE,
265 FEC_GROUP_USABLE,
266 FEC_GROUP_USABLE_SKIP_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;
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 = 0, need;
292 struct private_fecdec_data *pfd = fn->private_data;
293 enum fec_group_usability u = group_is_usable(fg, pfd);
294
295 if (u == FEC_GROUP_UNUSABLE) {
296 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
297 return 0;
298 }
299 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg->h.group_num,
300 fg->h.data_slices_per_group);
301 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
302 if (ret < 0)
303 return ret;
304 pfd->have_header = 1;
305 i = 0;
306 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
307 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
308 / fg->h.slice_bytes;
309 PARA_DEBUG_LOG("skipping %d header slices\n", i);
310 }
311 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
312 fg->h.group_num, fg->h.group_bytes,
313 fg->h.data_slices_per_group * sb);
314 need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
315 if (need > fn->bufsize) {
316 fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
317 if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
318 return -E_FECDEC_OVERRUN;
319 PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
320 fn->buf = para_realloc(fn->buf, fn->bufsize);
321 }
322 for (; i < fg->h.data_slices_per_group; i++) {
323 size_t n = sb;
324 if (n + written > fg->h.group_bytes)
325 n = fg->h.group_bytes - written;
326 memcpy(fn->buf + fn->loaded, fg->data[i], n);
327 fn->loaded += n;
328 written += n;
329 }
330 return 0;
331 }
332
333 /**
334 * Read a fec header from a buffer.
335 *
336 * \param buf The buffer to write to.
337 * \param h The fec header to write.
338 */
339 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
340 {
341 uint32_t magic;
342
343 if (len < FEC_HEADER_SIZE)
344 return 0;
345 magic = read_u32(buf);
346 if (magic != FEC_MAGIC)
347 return -E_BAD_FEC_HEADER;
348 h->slices_per_group = read_u8(buf + 4);
349 h->data_slices_per_group = read_u8(buf + 5);
350 h->audio_header_size = read_u32(buf + 6);
351
352 h->group_num = read_u32(buf + 10);
353 h->group_bytes = read_u32(buf + 14);
354
355 h->slice_num = read_u8(buf + 18);
356 h->slice_bytes = read_u16(buf + 20);
357 h->bos = read_u8(buf + 22);
358 h->header_stream = read_u8(buf + 23);
359 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
360 return -E_FECDEC_EOF;
361 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
362 // h->group_num, h->slice_num, h->slices_per_group);
363 return 1;
364 }
365
366 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
367 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
368 struct filter_node *fn)
369 {
370 struct fecdec_group *fg;
371 int ret, k, n;
372 struct private_fecdec_data *pfd = fn->private_data;
373
374 if (h->slice_bytes > len) /* can not use the thing, try to read more */
375 return 0;
376 ret = get_group(h, pfd, &fg);
377 if (ret < 0)
378 return ret;
379 if (!add_slice(buf, fg))
380 return 1;
381 if (group_complete(fg)) {
382 if (pfd->completion_status == GCS_NO_COMPLETE_GROUP) {
383 pfd->completion_status = GCS_FIRST_GROUP_COMPLETE;
384 pfd->first_complete_group = fg;
385 return 1;
386 }
387 assert(pfd->fec);
388 ret = decode_group(fg, fn);
389 if (ret < 0)
390 return ret;
391 return 1;
392 }
393 if (pfd->completion_status == GCS_NO_COMPLETE_GROUP)
394 return 1;
395 if (pfd->completion_status == GCS_FIRST_GROUP_DECODED)
396 return 1;
397 if (fg == pfd->first_complete_group)
398 return 1;
399 assert(!pfd->fec);
400 k = h->data_slices_per_group;
401 n = h->slices_per_group;
402 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
403 ret = fec_new(k, n, &pfd->fec);
404 if (ret < 0)
405 return ret;
406 ret = decode_group(pfd->first_complete_group, fn);
407 if (ret < 0)
408 return ret;
409 pfd->completion_status = GCS_FIRST_GROUP_DECODED;
410 return 1;
411 }
412
413 static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
414 {
415 int ret;
416 struct fec_header h;
417
418 ret = read_fec_header(buf, len, &h);
419 if (ret <= 0)
420 return ret;
421 if (!h.slice_bytes)
422 return -E_BAD_SLICE_SIZE;
423 if (h.slice_num > h.slices_per_group)
424 return -E_BAD_SLICE_NUM;
425 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
426 &h, fn);
427 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
428 if (ret <= 0)
429 return ret;
430 return FEC_HEADER_SIZE + h.slice_bytes;
431 }
432
433 static void fecdec_close(struct filter_node *fn)
434 {
435 struct private_fecdec_data *pfd = fn->private_data;
436 struct fecdec_group *fg;
437
438 FOR_EACH_FECDEC_GROUP(fg, pfd)
439 clear_group(fg);
440 free(fn->buf);
441 fn->buf = NULL;
442 fec_free(pfd->fec);
443 free(fn->private_data);
444 fn->private_data = NULL;
445 }
446
447 static void fecdec_open(struct filter_node *fn)
448 {
449 struct private_fecdec_data *pfd;
450 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
451 fn->buf = para_malloc(fn->bufsize);
452 pfd = para_calloc(sizeof(*pfd));
453 pfd->completion_status = GCS_NO_COMPLETE_GROUP;
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 }