Merge branch 'master' into next
[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 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 * Data private to the fecdec filter.
75 */
76 struct private_fecdec_data {
77 /** Used by the fec core code. */
78 struct fec_parms *fec;
79 /** Keeps track of what was received so far. */
80 struct fecdec_group groups[NUM_FEC_GROUPS];
81 int have_header;
82 };
83
84 /** Iterate over all fecdec groups. */
85 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
86 (g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
87
88 static int group_complete(struct fecdec_group *fg)
89 {
90 return fg->num_received_slices >= fg->h.data_slices_per_group;
91 }
92
93 static int group_empty(struct fecdec_group *fg)
94 {
95 return fg->num_received_slices == 0;
96 }
97
98 static void clear_group(struct fecdec_group *fg)
99 {
100 int i;
101
102 for (i = 0; i < fg->num_slices; i++) {
103 free(fg->data[i]);
104 fg->data[i] = NULL;
105 fg->idx[i] = -1;
106 }
107 free(fg->data);
108 free(fg->idx);
109 fg->num_slices = 0;
110 memset(&fg->h, 0, sizeof(struct fec_header));
111 fg->num_received_slices = 0;
112 }
113
114 static int find_group(struct fec_header *h,
115 struct private_fecdec_data *pfd, struct fecdec_group **result)
116 {
117 struct fecdec_group *fg;
118
119 FOR_EACH_FECDEC_GROUP(fg, pfd) {
120 if (fg->h.group_num != h->group_num)
121 continue;
122 if (fg->num_received_slices == 0)
123 goto success;
124 if (fg->h.slices_per_group != h->slices_per_group)
125 return -E_BAD_FEC_HEADER;
126 if (fg->h.data_slices_per_group != h->data_slices_per_group)
127 return -E_BAD_FEC_HEADER;
128 if (fg->h.group_bytes != h->group_bytes)
129 return -E_BAD_FEC_HEADER;
130 success:
131 *result = fg;
132 return 1;
133 }
134 return 0;
135 }
136
137 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
138 {
139 struct fecdec_group *fg;
140
141 FOR_EACH_FECDEC_GROUP(fg, pfd) {
142 if (fg->num_received_slices == 0)
143 return fg;
144 }
145 return NULL;
146 }
147
148 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
149 {
150 struct fecdec_group *fg;
151
152 FOR_EACH_FECDEC_GROUP(fg, pfd) {
153 if (!group_complete(fg))
154 continue;
155 clear_group(fg);
156 return fg;
157 }
158 return NULL;
159 }
160
161 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
162 {
163 struct fecdec_group *fg, *oldest = NULL;
164
165 FOR_EACH_FECDEC_GROUP(fg, pfd) {
166 if (!oldest || oldest->h.group_num > fg->h.group_num)
167 oldest = fg;
168 }
169 if (!group_complete(oldest) && !group_empty(oldest))
170 PARA_WARNING_LOG("Clearing incomplete group %d "
171 "(contains %d slices)\n", oldest->h.group_num,
172 oldest->num_received_slices);
173 clear_group(oldest);
174 return oldest;
175 }
176
177 /* returns 1 if the group was found, 0 if not, negative on errors */
178 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
179 struct fecdec_group **result)
180 {
181 struct fecdec_group *fg;
182 int ret = find_group(h, pfd, &fg);
183
184 if (ret < 0)
185 return ret;
186 if (ret > 0) /* found group */
187 goto success;
188 /* group not found */
189 fg = find_unused_group(pfd);
190 if (fg)
191 goto success;
192 fg = try_to_free_group(pfd);
193 if (fg)
194 goto success;
195 fg = free_oldest_group(pfd);
196 ret = 0;
197 success:
198 fg->h = *h;
199 *result = fg;
200 return ret;
201 }
202
203 /*
204 * returns 1 if slice was added, zero otherwise (because the group was already
205 * complete). In any case the number of received slices is being increased by
206 * one.
207 */
208 static int add_slice(char *buf, struct fecdec_group *fg)
209 {
210 int r, slice_num;
211
212 if (group_complete(fg)) {
213 PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
214 fg->h.slice_num);
215 fg->num_received_slices++;
216 return 0;
217 }
218 slice_num = fg->h.slice_num;
219 if (fg->num_slices == 0) {
220 fg->num_slices = fg->h.slices_per_group;
221 fg->idx = malloc(fg->num_slices * sizeof(int));
222 fg->data = malloc(fg->num_slices * sizeof(unsigned char *));
223 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
224 }
225 r = fg->num_received_slices;
226 fg->idx[r] = slice_num;
227 fg->data[r] = malloc(fg->h.slice_bytes);
228 memcpy(fg->data[r], buf, fg->h.slice_bytes);
229 fg->num_received_slices++;
230 return 1;
231 }
232
233 enum fec_group_usability {
234 FEC_GROUP_UNUSABLE,
235 FEC_GROUP_USABLE,
236 FEC_GROUP_USABLE_SKIP_HEADER,
237 };
238
239 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
240 struct private_fecdec_data *pfd)
241 {
242 struct fec_header *h = &fg->h;
243
244 if (!h->header_stream)
245 return FEC_GROUP_USABLE;
246 if (pfd->have_header) {
247 if (h->audio_header_size)
248 return FEC_GROUP_USABLE_SKIP_HEADER;
249 return FEC_GROUP_USABLE;
250 }
251 if (fg->h.bos)
252 return FEC_GROUP_USABLE;
253 if (fg->h.audio_header_size)
254 return FEC_GROUP_USABLE;
255 return FEC_GROUP_UNUSABLE;
256 }
257
258 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
259 {
260 int i, ret, sb = fg->h.slice_bytes;
261 size_t written = 0, need;
262 struct private_fecdec_data *pfd = fn->private_data;
263 enum fec_group_usability u = group_is_usable(fg, pfd);
264
265 if (u == FEC_GROUP_UNUSABLE) {
266 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
267 return 0;
268 }
269 PARA_DEBUG_LOG("decoding group %d %d slices\n", fg->h.group_num,
270 fg->h.data_slices_per_group);
271 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
272 if (ret < 0)
273 return ret;
274 pfd->have_header = 1;
275 i = 0;
276 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
277 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
278 / fg->h.slice_bytes;
279 PARA_DEBUG_LOG("skipping %d header slices\n", i);
280 }
281 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
282 fg->h.group_num, fg->h.group_bytes,
283 fg->h.data_slices_per_group * sb);
284 need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
285 if (need > fn->bufsize) {
286 fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
287 if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
288 return -E_FECDEC_OVERRUN;
289 PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
290 fn->buf = para_realloc(fn->buf, fn->bufsize);
291 }
292 for (; i < fg->h.data_slices_per_group; i++) {
293 size_t n = sb;
294 if (n + written > fg->h.group_bytes)
295 n = fg->h.group_bytes - written;
296 memcpy(fn->buf + fn->loaded, fg->data[i], n);
297 fn->loaded += n;
298 written += n;
299 }
300 return 0;
301 }
302
303 /**
304 * Read a fec header from a buffer.
305 *
306 * \param buf The buffer to write to.
307 * \param h The fec header to write.
308 */
309 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
310 {
311 uint32_t magic;
312
313 if (len < FEC_HEADER_SIZE)
314 return 0;
315 magic = read_u32(buf);
316 if (magic != FEC_MAGIC)
317 return -E_BAD_FEC_HEADER;
318 h->slices_per_group = read_u8(buf + 4);
319 h->data_slices_per_group = read_u8(buf + 5);
320 h->audio_header_size = read_u32(buf + 6);
321
322 h->group_num = read_u32(buf + 10);
323 h->group_bytes = read_u32(buf + 14);
324
325 h->slice_num = read_u8(buf + 18);
326 h->slice_bytes = read_u16(buf + 20);
327 h->bos = read_u8(buf + 22);
328 h->header_stream = read_u8(buf + 23);
329 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
330 return -E_FECDEC_EOF;
331 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
332 // h->group_num, h->slice_num, h->slices_per_group);
333 return 1;
334 }
335
336 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
337 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
338 struct filter_node *fn)
339 {
340 struct fecdec_group *fg;
341 int ret;
342 struct private_fecdec_data *pfd = fn->private_data;
343
344 if (h->slice_bytes > len) /* can not use the thing, try to read more */
345 return 0;
346 ret = get_group(h, pfd, &fg);
347 if (ret < 0)
348 return ret;
349 if (!add_slice(buf, fg))
350 return 1;
351 if (group_complete(fg)) {
352 if (!pfd->fec) {
353 int k = h->data_slices_per_group, n = h->slices_per_group;
354 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
355 ret = fec_new(k, n, &pfd->fec);
356 if (ret < 0)
357 return ret;
358 }
359 ret = decode_group(fg, fn);
360 if (ret < 0)
361 return ret;
362 }
363 return 1;
364 }
365
366 static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
367 {
368 int ret;
369 struct fec_header h;
370
371 ret = read_fec_header(buf, len, &h);
372 if (ret <= 0)
373 return ret;
374 if (!h.slice_bytes || h.slice_bytes > fn->bufsize)
375 return -E_BAD_SLICE_SIZE;
376 if (h.slice_num > h.slices_per_group)
377 return -E_BAD_SLICE_NUM;
378 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
379 &h, fn);
380 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
381 if (ret <= 0)
382 return ret;
383 return FEC_HEADER_SIZE + h.slice_bytes;
384 }
385
386 static void fecdec_close(struct filter_node *fn)
387 {
388 struct private_fecdec_data *pfd = fn->private_data;
389 struct fecdec_group *fg;
390
391 FOR_EACH_FECDEC_GROUP(fg, pfd)
392 clear_group(fg);
393 free(fn->buf);
394 fn->buf = NULL;
395 fec_free(pfd->fec);
396 free(fn->private_data);
397 fn->private_data = NULL;
398 }
399
400 static void fecdec_open(struct filter_node *fn)
401 {
402 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
403 fn->buf = para_malloc(fn->bufsize);
404 fn->private_data = para_calloc(sizeof(struct private_fecdec_data));
405 fn->loaded = 0;
406 }
407
408 /**
409 * The init function of the fecdec filter.
410 *
411 * \param f struct to initialize.
412 */
413 void fecdec_filter_init(struct filter *f)
414 {
415 f->convert = fecdec;
416 f->close = fecdec_close;
417 f->open = fecdec_open;
418 }