Merge commit 'athcx/next' 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 (16 * 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->h.slices_per_group != h->slices_per_group)
123 continue;
124 if (fg->h.data_slices_per_group != h->data_slices_per_group)
125 continue;
126 *result = fg;
127 return 1;
128 }
129 return 0;
130 }
131
132 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
133 {
134 struct fecdec_group *fg;
135
136 FOR_EACH_FECDEC_GROUP(fg, pfd) {
137 if (fg->num_received_slices == 0)
138 return fg;
139 }
140 return NULL;
141 }
142
143 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
144 {
145 struct fecdec_group *fg;
146
147 FOR_EACH_FECDEC_GROUP(fg, pfd) {
148 if (!group_complete(fg))
149 continue;
150 clear_group(fg);
151 return fg;
152 }
153 return NULL;
154 }
155
156 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
157 {
158 struct fecdec_group *fg, *oldest = NULL;
159
160 FOR_EACH_FECDEC_GROUP(fg, pfd) {
161 if (!oldest || oldest->h.group_num > fg->h.group_num)
162 oldest = fg;
163 }
164 if (!group_complete(oldest) && !group_empty(oldest))
165 PARA_WARNING_LOG("Clearing incomplete group %d "
166 "(contains %d slices)\n", fg->h.group_num,
167 fg->num_received_slices);
168 clear_group(oldest);
169 return oldest;
170 }
171
172 /* returns 1 if the group was found, 0 if not, negative on errors */
173 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
174 struct fecdec_group **result)
175 {
176 struct fecdec_group *fg;
177 int ret = find_group(h, pfd, &fg);
178
179 if (ret < 0)
180 return ret;
181 if (ret > 0) /* found group */
182 goto success;
183 /* group not found */
184 fg = find_unused_group(pfd);
185 if (fg)
186 goto success;
187 fg = try_to_free_group(pfd);
188 if (fg)
189 goto success;
190 fg = free_oldest_group(pfd);
191 ret = 0;
192 success:
193 fg->h = *h;
194 *result = fg;
195 return ret;
196 }
197
198 /*
199 * returns 1 if slice was added, zero otherwise (because the group was already
200 * complete). In any case the number of received slices is being increased by
201 * one.
202 */
203 static int add_slice(char *buf, struct fecdec_group *fg)
204 {
205 int r, slice_num;
206
207 if (group_complete(fg)) {
208 PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
209 fg->h.slice_num);
210 fg->num_received_slices++;
211 return 0;
212 }
213 slice_num = fg->h.slice_num;
214 if (fg->num_slices == 0) {
215 fg->num_slices = fg->h.slices_per_group;
216 fg->idx = malloc(fg->num_slices * sizeof(int));
217 fg->data = malloc(fg->num_slices * sizeof(unsigned char *));
218 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
219 }
220 r = fg->num_received_slices;
221 fg->idx[r] = slice_num;
222 fg->data[r] = malloc(fg->h.slice_bytes);
223 memcpy(fg->data[r], buf, fg->h.slice_bytes);
224 fg->num_received_slices++;
225 return 1;
226 }
227
228 enum fec_group_usability {
229 FEC_GROUP_UNUSABLE,
230 FEC_GROUP_USABLE,
231 FEC_GROUP_USABLE_SKIP_HEADER,
232 };
233
234 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
235 struct private_fecdec_data *pfd)
236 {
237 struct fec_header *h = &fg->h;
238
239 if (!h->header_stream)
240 return FEC_GROUP_USABLE;
241 if (pfd->have_header) {
242 if (h->audio_header_size)
243 return FEC_GROUP_USABLE_SKIP_HEADER;
244 return FEC_GROUP_USABLE;
245 }
246 if (fg->h.bos)
247 return FEC_GROUP_USABLE;
248 if (fg->h.audio_header_size)
249 return FEC_GROUP_USABLE;
250 return FEC_GROUP_UNUSABLE;
251 }
252
253 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
254 {
255 int i, ret, sb = fg->h.slice_bytes;
256 size_t written = 0, need;
257 struct private_fecdec_data *pfd = fn->private_data;
258 enum fec_group_usability u = group_is_usable(fg, pfd);
259
260 if (u == FEC_GROUP_UNUSABLE) {
261 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
262 return 0;
263 }
264 PARA_DEBUG_LOG("decoding group %d %d slices\n", fg->h.group_num,
265 fg->h.data_slices_per_group);
266 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
267 if (ret < 0)
268 return ret;
269 pfd->have_header = 1;
270 i = 0;
271 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
272 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
273 / fg->h.slice_bytes;
274 PARA_DEBUG_LOG("skipping %d header slices\n", i);
275 }
276 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
277 fg->h.group_num, fg->h.group_bytes,
278 fg->h.data_slices_per_group * sb);
279 need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
280 if (need > fn->bufsize) {
281 fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
282 if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
283 return -E_FECDEC_OVERRUN;
284 PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
285 fn->buf = para_realloc(fn->buf, fn->bufsize);
286 }
287 for (; i < fg->h.data_slices_per_group; i++) {
288 size_t n = sb;
289 if (n + written > fg->h.group_bytes)
290 n = fg->h.group_bytes - written;
291 memcpy(fn->buf + fn->loaded, fg->data[i], n);
292 fn->loaded += n;
293 written += n;
294 }
295 return 0;
296 }
297
298 /**
299 * Read a fec header from a buffer.
300 *
301 * \param buf The buffer to write to.
302 * \param h The fec header to write.
303 */
304 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
305 {
306 uint32_t magic;
307
308 if (len < FEC_HEADER_SIZE)
309 return 0;
310 magic = read_u32(buf);
311 if (magic != FEC_MAGIC)
312 return -E_BAD_FEC_HEADER;
313 h->slices_per_group = read_u8(buf + 4);
314 h->data_slices_per_group = read_u8(buf + 5);
315 h->audio_header_size = read_u32(buf + 6);
316
317 h->group_num = read_u32(buf + 10);
318 h->group_bytes = read_u32(buf + 14);
319
320 h->slice_num = read_u8(buf + 18);
321 h->slice_bytes = read_u16(buf + 20);
322 h->bos = read_u8(buf + 22);
323 h->header_stream = read_u8(buf + 23);
324 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
325 return -E_FECDEC_EOF;
326 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
327 // h->group_num, h->slice_num, h->slices_per_group);
328 return 1;
329 }
330
331 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
332 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
333 struct filter_node *fn)
334 {
335 struct fecdec_group *fg;
336 int ret;
337 struct private_fecdec_data *pfd = fn->private_data;
338
339 if (h->slice_bytes > len) /* can not use the thing, try to read more */
340 return 0;
341 ret = get_group(h, pfd, &fg);
342 if (ret < 0)
343 return ret;
344 if (!add_slice(buf, fg))
345 return 1;
346 if (group_complete(fg)) {
347 if (!pfd->fec) {
348 int k = h->data_slices_per_group, n = h->slices_per_group;
349 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
350 ret = fec_new(k, n, &pfd->fec);
351 if (ret < 0)
352 return ret;
353 }
354 ret = decode_group(fg, fn);
355 if (ret < 0)
356 return ret;
357 }
358 return 1;
359 }
360
361 static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
362 {
363 int ret;
364 struct fec_header h;
365
366 ret = read_fec_header(buf, len, &h);
367 if (ret <= 0)
368 return ret;
369 if (!h.slice_bytes || h.slice_bytes > fn->bufsize)
370 return -E_BAD_SLICE_SIZE;
371 if (h.slice_num > h.slices_per_group)
372 return -E_BAD_SLICE_NUM;
373 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
374 &h, fn);
375 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
376 if (ret <= 0)
377 return ret;
378 return FEC_HEADER_SIZE + h.slice_bytes;
379 }
380
381 static void fecdec_close(struct filter_node *fn)
382 {
383 struct private_fecdec_data *pfd = fn->private_data;
384 struct fecdec_group *fg;
385
386 FOR_EACH_FECDEC_GROUP(fg, pfd)
387 clear_group(fg);
388 free(fn->buf);
389 fn->buf = NULL;
390 fec_free(pfd->fec);
391 free(fn->private_data);
392 fn->private_data = NULL;
393 }
394
395 static void fecdec_open(struct filter_node *fn)
396 {
397 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
398 fn->buf = para_malloc(fn->bufsize);
399 fn->private_data = para_calloc(sizeof(struct private_fecdec_data));
400 fn->loaded = 0;
401 }
402
403 /**
404 * The init function of the fecdec filter.
405 *
406 * \param f struct to initialize.
407 */
408 void fecdec_filter_init(struct filter *f)
409 {
410 f->convert = fecdec;
411 f->close = fecdec_close;
412 f->open = fecdec_open;
413 }