2 * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file fecdec_filter.c A filter fec-decodes an audio stream. */
17 #include "portable_io.h"
22 * How many FEC groups to store in memory.
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
28 #define NUM_FEC_GROUPS 3
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)
35 /** Data read from the header of a slice. */
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. */
45 /** Size of the data in this FEC group. */
47 /** Number of this slice in the group. */
49 /** Used data bytes of this slice. */
51 /** Non-zero if this group is the beginning of the stream. */
53 /** Non-zero if this stream embedds audio headers into fec groups. */
54 uint8_t header_stream
;
58 * The status of one partially received FEC group.
61 /** The header read from the last slice. */
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. */
67 /** Array of indices of the received slices. */
69 /** Content of the received slices. */
74 * Data private to the fecdec filter.
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
];
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)++)
88 static int group_complete(struct fecdec_group
*fg
)
90 return fg
->num_received_slices
>= fg
->h
.data_slices_per_group
;
93 static int group_empty(struct fecdec_group
*fg
)
95 return fg
->num_received_slices
== 0;
98 static void clear_group(struct fecdec_group
*fg
)
102 for (i
= 0; i
< fg
->num_slices
; i
++) {
110 memset(&fg
->h
, 0, sizeof(struct fec_header
));
111 fg
->num_received_slices
= 0;
114 static int find_group(struct fec_header
*h
,
115 struct private_fecdec_data
*pfd
, struct fecdec_group
**result
)
117 struct fecdec_group
*fg
;
119 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
120 if (fg
->h
.group_num
!= h
->group_num
)
122 if (fg
->num_received_slices
== 0)
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
;
137 static struct fecdec_group
*find_unused_group(struct private_fecdec_data
*pfd
)
139 struct fecdec_group
*fg
;
141 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
142 if (fg
->num_received_slices
== 0)
148 static struct fecdec_group
*try_to_free_group(struct private_fecdec_data
*pfd
)
150 struct fecdec_group
*fg
;
152 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
153 if (!group_complete(fg
))
161 static struct fecdec_group
*free_oldest_group(struct private_fecdec_data
*pfd
)
163 struct fecdec_group
*fg
, *oldest
= NULL
;
165 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
166 if (!oldest
|| oldest
->h
.group_num
> fg
->h
.group_num
)
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
);
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
)
181 struct fecdec_group
*fg
;
182 int ret
= find_group(h
, pfd
, &fg
);
186 if (ret
> 0) /* found group */
188 /* group not found */
189 fg
= find_unused_group(pfd
);
192 fg
= try_to_free_group(pfd
);
195 fg
= free_oldest_group(pfd
);
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
208 static int add_slice(char *buf
, struct fecdec_group
*fg
)
212 if (group_complete(fg
)) {
213 PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
215 fg
->num_received_slices
++;
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 *));
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
++;
233 enum fec_group_usability
{
236 FEC_GROUP_USABLE_SKIP_HEADER
,
239 static enum fec_group_usability
group_is_usable(struct fecdec_group
*fg
,
240 struct private_fecdec_data
*pfd
)
242 struct fec_header
*h
= &fg
->h
;
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
;
252 return FEC_GROUP_USABLE
;
253 if (fg
->h
.audio_header_size
)
254 return FEC_GROUP_USABLE
;
255 return FEC_GROUP_UNUSABLE
;
258 static int decode_group(struct fecdec_group
*fg
, struct filter_node
*fn
)
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
);
265 if (u
== FEC_GROUP_UNUSABLE
) {
266 PARA_INFO_LOG("dropping unusable group %d\n", fg
->h
.group_num
);
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
);
274 pfd
->have_header
= 1;
276 if (u
== FEC_GROUP_USABLE_SKIP_HEADER
) {
277 i
= ROUND_UP(fg
->h
.audio_header_size
, fg
->h
.slice_bytes
)
279 PARA_DEBUG_LOG("skipping %d header slices\n", i
);
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
);
292 for (; i
< fg
->h
.data_slices_per_group
; i
++) {
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
);
304 * Read a fec header from a buffer.
306 * \param buf The buffer to write to.
307 * \param h The fec header to write.
309 static int read_fec_header(char *buf
, size_t len
, struct fec_header
*h
)
313 if (len
< FEC_HEADER_SIZE
)
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);
322 h
->group_num
= read_u32(buf
+ 10);
323 h
->group_bytes
= read_u32(buf
+ 14);
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);
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
)
340 struct fecdec_group
*fg
;
342 struct private_fecdec_data
*pfd
= fn
->private_data
;
344 if (h
->slice_bytes
> len
) /* can not use the thing, try to read more */
346 ret
= get_group(h
, pfd
, &fg
);
349 if (!add_slice(buf
, fg
))
351 if (group_complete(fg
)) {
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
);
359 ret
= decode_group(fg
, fn
);
366 static ssize_t
fecdec(char *buf
, size_t len
, struct filter_node
*fn
)
371 ret
= read_fec_header(buf
, len
, &h
);
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
,
380 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
383 return FEC_HEADER_SIZE
+ h
.slice_bytes
;
386 static void fecdec_close(struct filter_node
*fn
)
388 struct private_fecdec_data
*pfd
= fn
->private_data
;
389 struct fecdec_group
*fg
;
391 FOR_EACH_FECDEC_GROUP(fg
, pfd
)
396 free(fn
->private_data
);
397 fn
->private_data
= NULL
;
400 static void fecdec_open(struct filter_node
*fn
)
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
));
409 * The init function of the fecdec filter.
411 * \param f struct to initialize.
413 void fecdec_filter_init(struct filter
*f
)
416 f
->close
= fecdec_close
;
417 f
->open
= fecdec_open
;