Major audio format handler cleanups.
[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 /** Whether an audio file header was already received. */
82 int have_header;
83 };
84
85 /** Iterate over all fecdec groups. */
86 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
87 (g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
88
89 static int group_complete(struct fecdec_group *fg)
90 {
91 return fg->num_received_slices >= fg->h.data_slices_per_group;
92 }
93
94 static int group_empty(struct fecdec_group *fg)
95 {
96 return fg->num_received_slices == 0;
97 }
98
99 static void clear_group(struct fecdec_group *fg)
100 {
101 int i;
102
103 for (i = 0; i < fg->num_slices; i++) {
104 free(fg->data[i]);
105 fg->data[i] = NULL;
106 fg->idx[i] = -1;
107 }
108 free(fg->data);
109 free(fg->idx);
110 fg->num_slices = 0;
111 memset(&fg->h, 0, sizeof(struct fec_header));
112 fg->num_received_slices = 0;
113 }
114
115 static int find_group(struct fec_header *h,
116 struct private_fecdec_data *pfd, struct fecdec_group **result)
117 {
118 struct fecdec_group *fg;
119
120 FOR_EACH_FECDEC_GROUP(fg, pfd) {
121 if (fg->h.group_num != h->group_num)
122 continue;
123 if (fg->num_received_slices == 0)
124 goto success;
125 if (fg->h.slices_per_group != h->slices_per_group)
126 return -E_BAD_FEC_HEADER;
127 if (fg->h.data_slices_per_group != h->data_slices_per_group)
128 return -E_BAD_FEC_HEADER;
129 if (fg->h.group_bytes != h->group_bytes)
130 return -E_BAD_FEC_HEADER;
131 success:
132 *result = fg;
133 return 1;
134 }
135 return 0;
136 }
137
138 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
139 {
140 struct fecdec_group *fg;
141
142 FOR_EACH_FECDEC_GROUP(fg, pfd) {
143 if (fg->num_received_slices == 0)
144 return fg;
145 }
146 return NULL;
147 }
148
149 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
150 {
151 struct fecdec_group *fg;
152
153 FOR_EACH_FECDEC_GROUP(fg, pfd) {
154 if (!group_complete(fg))
155 continue;
156 clear_group(fg);
157 return fg;
158 }
159 return NULL;
160 }
161
162 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
163 {
164 struct fecdec_group *fg, *oldest = NULL;
165
166 FOR_EACH_FECDEC_GROUP(fg, pfd) {
167 if (!oldest || oldest->h.group_num > fg->h.group_num)
168 oldest = fg;
169 }
170 if (!group_complete(oldest) && !group_empty(oldest))
171 PARA_WARNING_LOG("Clearing incomplete group %d "
172 "(contains %d slices)\n", oldest->h.group_num,
173 oldest->num_received_slices);
174 clear_group(oldest);
175 return oldest;
176 }
177
178 /* returns 1 if the group was found, 0 if not, negative on errors */
179 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
180 struct fecdec_group **result)
181 {
182 struct fecdec_group *fg;
183 int ret = find_group(h, pfd, &fg);
184
185 if (ret < 0)
186 return ret;
187 if (ret > 0) /* found group */
188 goto success;
189 /* group not found */
190 fg = find_unused_group(pfd);
191 if (fg)
192 goto success;
193 fg = try_to_free_group(pfd);
194 if (fg)
195 goto success;
196 fg = free_oldest_group(pfd);
197 ret = 0;
198 success:
199 fg->h = *h;
200 *result = fg;
201 return ret;
202 }
203
204 /*
205 * returns 1 if slice was added, zero otherwise (because the group was already
206 * complete). In any case the number of received slices is being increased by
207 * one.
208 */
209 static int add_slice(char *buf, struct fecdec_group *fg)
210 {
211 int r, slice_num;
212
213 if (group_complete(fg)) {
214 PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
215 fg->h.slice_num);
216 fg->num_received_slices++;
217 return 0;
218 }
219 slice_num = fg->h.slice_num;
220 if (fg->num_slices == 0) {
221 fg->num_slices = fg->h.slices_per_group;
222 fg->idx = malloc(fg->num_slices * sizeof(int));
223 fg->data = malloc(fg->num_slices * sizeof(unsigned char *));
224 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
225 }
226 r = fg->num_received_slices;
227 fg->idx[r] = slice_num;
228 fg->data[r] = malloc(fg->h.slice_bytes);
229 memcpy(fg->data[r], buf, fg->h.slice_bytes);
230 fg->num_received_slices++;
231 return 1;
232 }
233
234 enum fec_group_usability {
235 FEC_GROUP_UNUSABLE,
236 FEC_GROUP_USABLE,
237 FEC_GROUP_USABLE_SKIP_HEADER,
238 };
239
240 static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
241 struct private_fecdec_data *pfd)
242 {
243 struct fec_header *h = &fg->h;
244
245 if (!h->header_stream)
246 return FEC_GROUP_USABLE;
247 if (pfd->have_header) {
248 if (h->audio_header_size)
249 return FEC_GROUP_USABLE_SKIP_HEADER;
250 return FEC_GROUP_USABLE;
251 }
252 if (fg->h.bos)
253 return FEC_GROUP_USABLE;
254 if (fg->h.audio_header_size)
255 return FEC_GROUP_USABLE;
256 return FEC_GROUP_UNUSABLE;
257 }
258
259 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
260 {
261 int i, ret, sb = fg->h.slice_bytes;
262 size_t written = 0, need;
263 struct private_fecdec_data *pfd = fn->private_data;
264 enum fec_group_usability u = group_is_usable(fg, pfd);
265
266 if (u == FEC_GROUP_UNUSABLE) {
267 PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
268 return 0;
269 }
270 PARA_DEBUG_LOG("decoding group %d %d slices\n", fg->h.group_num,
271 fg->h.data_slices_per_group);
272 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
273 if (ret < 0)
274 return ret;
275 pfd->have_header = 1;
276 i = 0;
277 if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
278 i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
279 / fg->h.slice_bytes;
280 PARA_DEBUG_LOG("skipping %d header slices\n", i);
281 }
282 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
283 fg->h.group_num, fg->h.group_bytes,
284 fg->h.data_slices_per_group * sb);
285 need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
286 if (need > fn->bufsize) {
287 fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
288 if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
289 return -E_FECDEC_OVERRUN;
290 PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
291 fn->buf = para_realloc(fn->buf, fn->bufsize);
292 }
293 for (; i < fg->h.data_slices_per_group; i++) {
294 size_t n = sb;
295 if (n + written > fg->h.group_bytes)
296 n = fg->h.group_bytes - written;
297 memcpy(fn->buf + fn->loaded, fg->data[i], n);
298 fn->loaded += n;
299 written += n;
300 }
301 return 0;
302 }
303
304 /**
305 * Read a fec header from a buffer.
306 *
307 * \param buf The buffer to write to.
308 * \param h The fec header to write.
309 */
310 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
311 {
312 uint32_t magic;
313
314 if (len < FEC_HEADER_SIZE)
315 return 0;
316 magic = read_u32(buf);
317 if (magic != FEC_MAGIC)
318 return -E_BAD_FEC_HEADER;
319 h->slices_per_group = read_u8(buf + 4);
320 h->data_slices_per_group = read_u8(buf + 5);
321 h->audio_header_size = read_u32(buf + 6);
322
323 h->group_num = read_u32(buf + 10);
324 h->group_bytes = read_u32(buf + 14);
325
326 h->slice_num = read_u8(buf + 18);
327 h->slice_bytes = read_u16(buf + 20);
328 h->bos = read_u8(buf + 22);
329 h->header_stream = read_u8(buf + 23);
330 if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
331 return -E_FECDEC_EOF;
332 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
333 // h->group_num, h->slice_num, h->slices_per_group);
334 return 1;
335 }
336
337 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
338 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
339 struct filter_node *fn)
340 {
341 struct fecdec_group *fg;
342 int ret;
343 struct private_fecdec_data *pfd = fn->private_data;
344
345 if (h->slice_bytes > len) /* can not use the thing, try to read more */
346 return 0;
347 ret = get_group(h, pfd, &fg);
348 if (ret < 0)
349 return ret;
350 if (!add_slice(buf, fg))
351 return 1;
352 if (group_complete(fg)) {
353 if (!pfd->fec) {
354 int k = h->data_slices_per_group, n = h->slices_per_group;
355 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
356 ret = fec_new(k, n, &pfd->fec);
357 if (ret < 0)
358 return ret;
359 }
360 ret = decode_group(fg, fn);
361 if (ret < 0)
362 return ret;
363 }
364 return 1;
365 }
366
367 static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
368 {
369 int ret;
370 struct fec_header h;
371
372 ret = read_fec_header(buf, len, &h);
373 if (ret <= 0)
374 return ret;
375 if (!h.slice_bytes)
376 return -E_BAD_SLICE_SIZE;
377 if (h.slice_num > h.slices_per_group)
378 return -E_BAD_SLICE_NUM;
379 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
380 &h, fn);
381 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
382 if (ret <= 0)
383 return ret;
384 return FEC_HEADER_SIZE + h.slice_bytes;
385 }
386
387 static void fecdec_close(struct filter_node *fn)
388 {
389 struct private_fecdec_data *pfd = fn->private_data;
390 struct fecdec_group *fg;
391
392 FOR_EACH_FECDEC_GROUP(fg, pfd)
393 clear_group(fg);
394 free(fn->buf);
395 fn->buf = NULL;
396 fec_free(pfd->fec);
397 free(fn->private_data);
398 fn->private_data = NULL;
399 }
400
401 static void fecdec_open(struct filter_node *fn)
402 {
403 fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
404 fn->buf = para_malloc(fn->bufsize);
405 fn->private_data = para_calloc(sizeof(struct private_fecdec_data));
406 fn->loaded = 0;
407 }
408
409 /**
410 * The init function of the fecdec filter.
411 *
412 * \param f struct to initialize.
413 */
414 void fecdec_filter_init(struct filter *f)
415 {
416 f->convert = fecdec;
417 f->close = fecdec_close;
418 f->open = fecdec_open;
419 }