Merge commit 'meins/maint' into 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 <dirent.h>
10 #include "para.h"
11 #include "error.h"
12 #include "list.h"
13 #include "sched.h"
14 #include "ggo.h"
15 #include "filter.h"
16 #include "string.h"
17 #include "portable_io.h"
18 #include "fec.h"
19 #include "fd.h"
20
21 /**
22 * How many FEC groups to store in memory.
23 *
24 * Packet reordering requires to keep more than one FEC group in memory because
25 * slices belonging to the next FEC group may arrive before the current FEC group
26 * is complete.
27 */
28 #define NUM_FEC_GROUPS 3
29
30 /** Default size of the output buffer of the fecdec filter. */
31 #define FECDEC_DEFAULT_OUTBUF_SIZE (3 * 1024)
32 /** Maximal size of the output buffer of the fecdec filter. */
33 #define FECDEC_MAX_OUTBUF_SIZE (1024 * 1024)
34
35 /** Data read from the header of a slice. */
36 struct fec_header {
37 /** Total number of slices in this group. */
38 uint8_t slices_per_group;
39 /** Number of slices needed to start decoding. */
40 uint8_t data_slices_per_group;
41 /** Size of the ogg vorbis header (zero for mp3, aac). */
42 uint32_t audio_header_size;
43 /** Number of the FEC group this slice belongs to. */
44 uint32_t group_num;
45 /** Size of the data in this FEC group. */
46 uint32_t group_bytes;
47 /** Number of this slice in the group. */
48 uint8_t slice_num;
49 /** Used data bytes of this slice. */
50 uint16_t slice_bytes;
51 /** Non-zero if this group is the beginning of the stream. */
52 uint8_t bos;
53 /** Non-zero if this stream embedds audio headers into fec groups. */
54 uint8_t header_stream;
55 };
56
57 /**
58 * The status of one partially received FEC group.
59 */
60 struct fecdec_group {
61 /** The header read from the last slice. */
62 struct fec_header h;
63 /** How many slices received so far. */
64 int num_received_slices;
65 /** The size of the \a idx and the \a data arrays below. */
66 int num_slices;
67 /** Array of indices of the received slices. */
68 int *idx;
69 /** Content of the received slices. */
70 unsigned char **data;
71 };
72
73 /**
74 * The fecdec filter defers decoding of the first group until the first slice
75 * of the next group was received. This avoids buffer underruns in subsequent
76 * filters of the filter chain.
77 */
78 enum group_completion_status {
79 /** No complete group received so far. */
80 GCS_NO_COMPLETE_GROUP,
81 /** First group received, but not yet decoded. */
82 GCS_FIRST_GROUP_COMPLETE,
83 /** At least one complete group decoded. */
84 GCS_FIRST_GROUP_DECODED,
85 };
86
87 /**
88 * Data private to the fecdec filter.
89 */
90 struct private_fecdec_data {
91 /** Used by the fec core code. */
92 struct fec_parms *fec;
93 /** Keeps track of what was received so far. */
94 struct fecdec_group groups[NUM_FEC_GROUPS];
95 /** Whether an audio file header was already received. */
96 int have_header;
97 /** See \ref group_completion_status. */
98 unsigned completion_status;
99 /** Points to the first received group. */
100 struct fecdec_group *first_complete_group;
101 };
102
103 /** Iterate over all fecdec groups. */
104 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
105 (g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
106
107 static int group_complete(struct fecdec_group *fg)
108 {
109 return fg->num_received_slices >= fg->h.data_slices_per_group;
110 }
111
112 static int group_empty(struct fecdec_group *fg)
113 {
114 return fg->num_received_slices == 0;
115 }
116
117 static void clear_group(struct fecdec_group *fg)
118 {
119 int i;
120
121 for (i = 0; i < fg->num_slices; i++) {
122 free(fg->data[i]);
123 fg->data[i] = NULL;
124 fg->idx[i] = -1;
125 }
126 free(fg->data);
127 free(fg->idx);
128 fg->num_slices = 0;
129 memset(&fg->h, 0, sizeof(struct fec_header));
130 fg->num_received_slices = 0;
131 }
132
133 static int find_group(struct fec_header *h,
134 struct private_fecdec_data *pfd, struct fecdec_group **result)
135 {
136 struct fecdec_group *fg;
137
138 FOR_EACH_FECDEC_GROUP(fg, pfd) {
139 if (fg->h.group_num != h->group_num)
140 continue;
141 if (fg->num_received_slices == 0)
142 goto success;
143 if (fg->h.slices_per_group != h->slices_per_group)
144 return -E_BAD_FEC_HEADER;
145 if (fg->h.data_slices_per_group != h->data_slices_per_group)
146 return -E_BAD_FEC_HEADER;
147 if (fg->h.group_bytes != h->group_bytes)
148 return -E_BAD_FEC_HEADER;
149 success:
150 *result = fg;
151 return 1;
152 }
153 return 0;
154 }
155
156 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
157 {
158 struct fecdec_group *fg;
159
160 FOR_EACH_FECDEC_GROUP(fg, pfd) {
161 if (fg->num_received_slices == 0)
162 return fg;
163 }
164 return NULL;
165 }
166
167 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
168 {
169 struct fecdec_group *fg;
170
171 FOR_EACH_FECDEC_GROUP(fg, pfd) {
172 if (!group_complete(fg))
173 continue;
174 /*
175 * Don't clear the first complete group if it has not yet been
176 * decoded.
177 */
178 if (pfd->completion_status == GCS_FIRST_GROUP_COMPLETE
179 && pfd->first_complete_group == fg)
180 continue;
181 clear_group(fg);
182 return fg;
183 }
184 return NULL;
185 }
186
187 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
188 {
189 struct fecdec_group *fg, *oldest = NULL;
190
191 FOR_EACH_FECDEC_GROUP(fg, pfd) {
192 if (!oldest || oldest->h.group_num > fg->h.group_num)
193 oldest = fg;
194 }
195 if (!group_complete(oldest) && !group_empty(oldest))
196 PARA_WARNING_LOG("Clearing incomplete group %d "
197 "(contains %d slices)\n", oldest->h.group_num,
198 oldest->num_received_slices);
199 assert(pfd->completion_status != GCS_FIRST_GROUP_COMPLETE
200 || oldest != pfd->first_complete_group);
201 clear_group(oldest);
202 return oldest;
203 }
204
205 /* returns 1 if the group was found, 0 if not, negative on errors */
206 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
207 struct fecdec_group **result)
208 {
209 struct fecdec_group *fg;
210 int ret = find_group(h, pfd, &fg);
211
212 if (ret < 0)
213 return ret;
214 if (ret > 0) /* found group */
215 goto success;
216 /* group not found */
217 fg = find_unused_group(pfd);
218 if (fg)
219 goto success;
220 fg = try_to_free_group(pfd);
221 if (fg)
222 goto success;
223 fg = free_oldest_group(pfd);
224 ret = 0;
225 success:
226 fg->h = *h;
227 *result = fg;
228 return ret;
229 }
230
231 /*
232 * returns 1 if slice was added, zero otherwise (because the group was already
233 * complete). In any case the number of received slices is being increased by
234 * one.
235 */
236 static int add_slice(char *buf, struct fecdec_group *fg)
237 {
238 int r, slice_num;
239
240 if (group_complete(fg)) {
241 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
242 fg->h.group_num, fg->h.slice_num);
243 fg->num_received_slices++;
244 return 0;
245 }
246 slice_num = fg->h.slice_num;
247 if (fg->num_slices == 0) {
248 fg->num_slices = fg->h.slices_per_group;
249 fg->idx = para_malloc(fg->num_slices * sizeof(int));
250 fg->data = para_malloc(fg->num_slices * sizeof(unsigned char *));
251 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
252 }
253 r = fg->num_received_slices;
254 fg->idx[r] = slice_num;
255 fg->data[r] = para_malloc(fg->h.slice_bytes);
256 memcpy(fg->data[r], buf, fg->h.slice_bytes);
257 fg->num_received_slices++;
258 return 1;
259 }
260
261 enum fec_group_usability {
262 FEC_GROUP_UNUSABLE,
263 FEC_GROUP_USABLE,
264 FEC_GROUP_USABLE_SKIP_HEADER,
265 FEC_GROUP_USABLE_WITH_HEADER
266 };
267
268 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
269 struct private_fecdec_data *pfd)
270 {
271 struct fec_header *h = &fg->h;
272
273 if (!h->header_stream)
274 return FEC_GROUP_USABLE;
275 if (pfd->have_header) {
276 if (h->audio_header_size)
277 return FEC_GROUP_USABLE_SKIP_HEADER;
278 return FEC_GROUP_USABLE;
279 }
280 if (fg->h.bos)
281 return FEC_GROUP_USABLE;
282 if (fg->h.audio_header_size)
283 return FEC_GROUP_USABLE_WITH_HEADER;
284 return FEC_GROUP_UNUSABLE;
285 }
286
287 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
288 {
289 int i, ret, sb = fg->h.slice_bytes;
290 size_t written, need;
291 struct private_fecdec_data *pfd = fn->private_data;
292 enum fec_group_usability u = group_is_usable(fg, pfd);
293
294 if (u == FEC_GROUP_UNUSABLE) {
295 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
296 return 0;
297 }
298 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg->h.group_num,
299 fg->h.data_slices_per_group);
300 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
301 if (ret < 0)
302 return ret;
303 pfd->have_header = 1;
304 i = 0;
305 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
306 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
307 / fg->h.slice_bytes;
308 PARA_DEBUG_LOG("skipping %d header slices\n", i);
309 }
310 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
311 fg->h.group_num, fg->h.group_bytes,
312 fg->h.data_slices_per_group * sb);
313 need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
314 if (need > fn->bufsize) {
315 fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
316 if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
317 return -E_FECDEC_OVERRUN;
318 PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
319 fn->buf = para_realloc(fn->buf, fn->bufsize);
320 }
321 if (u == FEC_GROUP_USABLE_WITH_HEADER) {
322 PARA_INFO_LOG("writing audio file header\n");
323 written = 0;
324 for (i = 0; i < fg->h.data_slices_per_group; i++) {
325 size_t n = sb;
326 if (written >= fg->h.audio_header_size)
327 break;
328 if (sb + written > fg->h.audio_header_size)
329 n = fg->h.audio_header_size - written;
330 memcpy(fn->buf + fn->loaded, fg->data[i], n);
331 fn->loaded += n;
332 written += n;
333 }
334 }
335 written = 0;
336 for (; i < fg->h.data_slices_per_group; i++) {
337 size_t n = sb;
338 if (n + written > fg->h.group_bytes)
339 n = fg->h.group_bytes - written;
340 memcpy(fn->buf + fn->loaded, fg->data[i], n);
341 fn->loaded += n;
342 written += n;
343 }
344 return 0;
345 }
346
347 /**
348 * Read a fec header from a buffer.
349 *
350 * \param buf The buffer to write to.
351 * \param h The fec header to write.
352 */
353 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
354 {
355 uint32_t magic;
356
357 if (len < FEC_HEADER_SIZE)
358 return 0;
359 magic = read_u32(buf);
360 if (magic != FEC_MAGIC)
361 return -E_BAD_FEC_HEADER;
362 h->slices_per_group = read_u8(buf + 4);
363 h->data_slices_per_group = read_u8(buf + 5);
364 h->audio_header_size = read_u32(buf + 6);
365
366 h->group_num = read_u32(buf + 10);
367 h->group_bytes = read_u32(buf + 14);
368
369 h->slice_num = read_u8(buf + 18);
370 h->slice_bytes = read_u16(buf + 20);
371 h->bos = read_u8(buf + 22);
372 h->header_stream = read_u8(buf + 23);
373 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
374 return -E_FECDEC_EOF;
375 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
376 // h->group_num, h->slice_num, h->slices_per_group);
377 return 1;
378 }
379
380 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
381 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
382 struct filter_node *fn)
383 {
384 struct fecdec_group *fg;
385 int ret, k, n;
386 struct private_fecdec_data *pfd = fn->private_data;
387
388 if (h->slice_bytes > len) /* can not use the thing, try to read more */
389 return 0;
390 ret = get_group(h, pfd, &fg);
391 if (ret < 0)
392 return ret;
393 if (!add_slice(buf, fg))
394 return 1;
395 if (group_complete(fg)) {
396 if (pfd->completion_status == GCS_NO_COMPLETE_GROUP) {
397 pfd->completion_status = GCS_FIRST_GROUP_COMPLETE;
398 pfd->first_complete_group = fg;
399 return 1;
400 }
401 assert(pfd->fec);
402 ret = decode_group(fg, fn);
403 if (ret < 0)
404 return ret;
405 return 1;
406 }
407 if (pfd->completion_status == GCS_NO_COMPLETE_GROUP)
408 return 1;
409 if (pfd->completion_status == GCS_FIRST_GROUP_DECODED)
410 return 1;
411 if (fg == pfd->first_complete_group)
412 return 1;
413 assert(!pfd->fec);
414 k = h->data_slices_per_group;
415 n = h->slices_per_group;
416 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
417 ret = fec_new(k, n, &pfd->fec);
418 if (ret < 0)
419 return ret;
420 ret = decode_group(pfd->first_complete_group, fn);
421 if (ret < 0)
422 return ret;
423 pfd->completion_status = GCS_FIRST_GROUP_DECODED;
424 return 1;
425 }
426
427 static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
428 {
429 int ret;
430 struct fec_header h;
431
432 ret = read_fec_header(buf, len, &h);
433 if (ret <= 0)
434 return ret;
435 if (!h.slice_bytes)
436 return -E_BAD_SLICE_SIZE;
437 if (h.slice_num > h.slices_per_group)
438 return -E_BAD_SLICE_NUM;
439 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
440 &h, fn);
441 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
442 if (ret <= 0)
443 return ret;
444 return FEC_HEADER_SIZE + h.slice_bytes;
445 }
446
447 static void fecdec_close(struct filter_node *fn)
448 {
449 struct private_fecdec_data *pfd = fn->private_data;
450 struct fecdec_group *fg;
451
452 FOR_EACH_FECDEC_GROUP(fg, pfd)
453 clear_group(fg);
454 free(fn->buf);
455 fn->buf = NULL;
456 fec_free(pfd->fec);
457 free(fn->private_data);
458 fn->private_data = NULL;
459 }
460
461 static void fecdec_open(struct filter_node *fn)
462 {
463 struct private_fecdec_data *pfd;
464 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
465 fn->buf = para_malloc(fn->bufsize);
466 pfd = para_calloc(sizeof(*pfd));
467 pfd->completion_status = GCS_NO_COMPLETE_GROUP;
468 fn->private_data = pfd;
469 fn->loaded = 0;
470 }
471
472 /**
473 * The init function of the fecdec filter.
474 *
475 * \param f struct to initialize.
476 */
477 void fecdec_filter_init(struct filter *f)
478 {
479 f->convert = fecdec;
480 f->close = fecdec_close;
481 f->open = fecdec_open;
482 }