6b6716a115c18c26429d12d49f38a40981314574
[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 /** Size of the output buffer of the fecdec filter. */
31 #define FECDEC_OUTBUF_SIZE 81920
32
33 /** Data read from the header of a slice. */
34 struct fec_header {
35 /** Total number of slices in this group. */
36 uint8_t slices_per_group;
37 /** Number of slices needed to start decoding. */
38 uint8_t data_slices_per_group;
39 /** Size of the ogg vorbis header (zero for mp3, aac). */
40 uint32_t audio_header_size;
41 /** Number of the FEC group this slice belongs to. */
42 uint32_t group_num;
43 /** Size of the data in this FEC group. */
44 uint32_t group_bytes;
45 /** Number of this slice in the group. */
46 uint8_t slice_num;
47 /** Used data bytes of this slice. */
48 uint16_t slice_bytes;
49 };
50
51 /**
52 * The status of one partially received FEC group.
53 */
54 struct fecdec_group {
55 /** The header read from the last slice. */
56 struct fec_header h;
57 /** How many slices received so far. */
58 int num_received_slices;
59 /** The size of the \a idx and the \a data arrays below. */
60 int num_slices;
61 /** Array of indices of the received slices. */
62 int *idx;
63 /** Content of the received slices. */
64 unsigned char **data;
65 };
66
67 /**
68 * Data private to the fecdec filter.
69 */
70 struct private_fecdec_data {
71 /** Used by the fec core code. */
72 struct fec_parms *fec;
73 /** Keeps track of what was received so far. */
74 struct fecdec_group groups[NUM_FEC_GROUPS];
75 };
76
77 /** Iterate over all fecdec groups. */
78 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
79 (g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
80
81 static int group_complete(struct fecdec_group *fg)
82 {
83 return fg->num_received_slices >= fg->h.data_slices_per_group;
84 }
85
86 static int group_empty(struct fecdec_group *fg)
87 {
88 return fg->num_received_slices == 0;
89 }
90
91 static void clear_group(struct fecdec_group *fg)
92 {
93 int i;
94
95 if (!group_complete(fg) && !group_empty(fg))
96 PARA_WARNING_LOG("Clearing incomplete group %d "
97 "(contains %d slices)\n", fg->h.group_num,
98 fg->num_received_slices);
99 for (i = 0; i < fg->num_slices; i++) {
100 free(fg->data[i]);
101 fg->data[i] = NULL;
102 fg->idx[i] = -1;
103 }
104 free(fg->data);
105 free(fg->idx);
106 fg->num_slices = 0;
107 memset(&fg->h, 0, sizeof(struct fec_header));
108 fg->num_received_slices = 0;
109 }
110
111 static int find_group(struct fec_header *h,
112 struct private_fecdec_data *pfd, struct fecdec_group **result)
113 {
114 struct fecdec_group *fg;
115
116 FOR_EACH_FECDEC_GROUP(fg, pfd) {
117 if (fg->h.group_num != h->group_num)
118 continue;
119 /* FIXME: Add some more sanity checks here */
120 *result = fg;
121 return 1;
122 }
123 return 0;
124 }
125
126 static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
127 {
128 struct fecdec_group *fg;
129
130 FOR_EACH_FECDEC_GROUP(fg, pfd) {
131 if (fg->num_received_slices == 0)
132 return fg;
133 }
134 return NULL;
135 }
136
137 static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
138 {
139 struct fecdec_group *fg;
140
141 FOR_EACH_FECDEC_GROUP(fg, pfd) {
142 if (!group_complete(fg))
143 continue;
144 clear_group(fg);
145 return fg;
146 }
147 return NULL;
148 }
149
150 static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
151 {
152 struct fecdec_group *fg, *oldest = NULL;
153
154 FOR_EACH_FECDEC_GROUP(fg, pfd) {
155 if (!oldest || oldest->h.group_num > fg->h.group_num)
156 oldest = fg;
157 }
158 clear_group(oldest);
159 return oldest;
160 }
161
162 static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
163 struct fecdec_group **result)
164 {
165 struct fecdec_group *fg;
166 int ret = find_group(h, pfd, &fg);
167
168 if (ret < 0)
169 return ret;
170 if (ret > 0) /* found group */
171 goto success;
172 /* group not found */
173 fg = find_unused_group(pfd);
174 if (fg)
175 goto update_header;
176 fg = try_to_free_group(pfd);
177 if (fg)
178 goto update_header;
179 fg = free_oldest_group(pfd);
180 update_header:
181 fg->h = *h;
182 success:
183 *result = fg;
184 return 1;
185 }
186
187 static int add_slice(char *buf, struct fecdec_group *fg)
188 {
189 int r, slice_num;
190
191 if (group_complete(fg))
192 return 0;
193 slice_num = fg->h.slice_num;
194 if (fg->num_slices == 0) {
195 fg->num_slices = fg->h.slices_per_group;
196 fg->idx = malloc(fg->num_slices * sizeof(int));
197 fg->data = malloc(fg->num_slices * sizeof(unsigned char *));
198 memset(fg->data, 0, fg->num_slices * sizeof(unsigned char *));
199 }
200 r = fg->num_received_slices;
201 fg->idx[r] = slice_num;
202 fg->data[r] = malloc(fg->h.slice_bytes);
203 memcpy(fg->data[r], buf, fg->h.slice_bytes);
204 fg->num_received_slices++;
205 return 1;
206 }
207
208 static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
209 {
210 int i, ret, sb = fg->h.slice_bytes;
211 size_t written = 0;
212 struct private_fecdec_data *pfd = fn->private_data;
213
214 ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
215 if (ret < 0)
216 return ret;
217 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
218 fg->h.group_num, fg->h.group_bytes,
219 fg->h.data_slices_per_group * sb);
220 for (i = 0; i < fg->h.data_slices_per_group; i++) {
221 size_t n = sb;
222 if (n + written > fg->h.group_bytes)
223 n = fg->h.group_bytes - written;
224 if (fn->loaded + n > fn->bufsize)
225 return -E_FECDEC_OVERRUN;
226 memcpy(fn->buf + fn->loaded, fg->data[i], n);
227 fn->loaded += n;
228 written += n;
229 }
230 return 0;
231 }
232
233 /**
234 * Read a fec header from a buffer.
235 *
236 * \param buf The buffer to write to.
237 * \param h The fec header to write.
238 */
239 static int read_fec_header(char *buf, size_t len, struct fec_header *h)
240 {
241 uint32_t magic;
242
243 if (len < FEC_HEADER_SIZE)
244 return 0;
245 magic = read_u32(buf);
246 if (magic != FEC_MAGIC)
247 return -E_BAD_FEC_HEADER;
248 h->slices_per_group = read_u8(buf + 4);
249 h->data_slices_per_group = read_u8(buf + 5);
250 h->audio_header_size = read_u32(buf + 6);
251
252 h->group_num = read_u32(buf + 10);
253 h->group_bytes = read_u32(buf + 14);
254
255 h->slice_num = read_u8(buf + 18);
256 h->slice_bytes = read_u16(buf + 20);
257 if (!h->group_bytes && & h->slice_bytes)
258 return -E_FECDEC_EOF;
259 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
260 // h->group_num, h->slice_num, h->slices_per_group);
261 return 1;
262 }
263
264 static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
265 struct filter_node *fn)
266 {
267 struct fecdec_group *fg;
268 int ret;
269 struct private_fecdec_data *pfd = fn->private_data;
270
271 if (h->slice_bytes > len) /* can not use the thing, try to read more */
272 return 0;
273 ret = get_group(h, pfd, &fg);
274 if (ret < 0)
275 return ret;
276 if (group_complete(fg)) {
277 PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
278 h->slice_num);
279 return 1;
280 }
281 fg->h = *h;
282 ret = add_slice(buf, fg);
283 if (ret < 0)
284 return ret;
285 if (group_complete(fg)) {
286 if (!pfd->fec) {
287 int k = h->data_slices_per_group, n = h->slices_per_group;
288 PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
289 ret = fec_new(k, n, &pfd->fec);
290 if (ret < 0)
291 return ret;
292 }
293 ret = decode_group(fg, fn);
294 if (ret < 0)
295 return ret;
296 }
297 return 1;
298 }
299
300 static int fecdec(char *buf, size_t len, struct filter_node *fn)
301 {
302 int ret;
303 struct fec_header h;
304
305 ret = read_fec_header(buf, len, &h);
306 if (ret <= 0)
307 return ret;
308 if (h.slice_bytes > fn->bufsize)
309 return -E_BAD_SLICE_SIZE;
310 if (h.slice_num > h.slices_per_group)
311 return -E_BAD_SLICE_NUM;
312 ret = dispatch_slice(buf + FEC_HEADER_SIZE, len - FEC_HEADER_SIZE,
313 &h, fn);
314 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
315 if (ret <= 0)
316 return ret;
317 return FEC_HEADER_SIZE + h.slice_bytes;
318 }
319
320 static void fecdec_close(struct filter_node *fn)
321 {
322 struct private_fecdec_data *pfd = fn->private_data;
323 struct fecdec_group *fg;
324
325 FOR_EACH_FECDEC_GROUP(fg, pfd)
326 clear_group(fg);
327 free(fn->buf);
328 fn->buf = NULL;
329 free(fn->private_data);
330 fn->private_data = NULL;
331 }
332
333 static void fecdec_open(struct filter_node *fn)
334 {
335 fn->bufsize = FECDEC_OUTBUF_SIZE;
336 fn->buf = para_malloc(fn->bufsize);
337 fn->private_data = para_calloc(sizeof(struct private_fecdec_data));
338 fn->loaded = 0;
339 }
340
341 /**
342 * The init function of the fecdec filter.
343 *
344 * \param f struct to initialize.
345 */
346 void fecdec_filter_init(struct filter *f)
347 {
348 f->convert = fecdec;
349 f->close = fecdec_close;
350 f->open = fecdec_open;
351 }