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 (16 * 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
->h
.slices_per_group
!= h
->slices_per_group
)
124 if (fg
->h
.data_slices_per_group
!= h
->data_slices_per_group
)
132 static struct fecdec_group
*find_unused_group(struct private_fecdec_data
*pfd
)
134 struct fecdec_group
*fg
;
136 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
137 if (fg
->num_received_slices
== 0)
143 static struct fecdec_group
*try_to_free_group(struct private_fecdec_data
*pfd
)
145 struct fecdec_group
*fg
;
147 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
148 if (!group_complete(fg
))
156 static struct fecdec_group
*free_oldest_group(struct private_fecdec_data
*pfd
)
158 struct fecdec_group
*fg
, *oldest
= NULL
;
160 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
161 if (!oldest
|| oldest
->h
.group_num
> fg
->h
.group_num
)
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
);
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
)
176 struct fecdec_group
*fg
;
177 int ret
= find_group(h
, pfd
, &fg
);
181 if (ret
> 0) /* found group */
183 /* group not found */
184 fg
= find_unused_group(pfd
);
187 fg
= try_to_free_group(pfd
);
190 fg
= free_oldest_group(pfd
);
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
203 static int add_slice(char *buf
, struct fecdec_group
*fg
)
207 if (group_complete(fg
)) {
208 PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
210 fg
->num_received_slices
++;
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 *));
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
++;
228 enum fec_group_usability
{
231 FEC_GROUP_USABLE_SKIP_HEADER
,
234 static enum fec_group_usability
group_is_usable(struct fecdec_group
*fg
,
235 struct private_fecdec_data
*pfd
)
237 struct fec_header
*h
= &fg
->h
;
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
;
247 return FEC_GROUP_USABLE
;
248 if (fg
->h
.audio_header_size
)
249 return FEC_GROUP_USABLE
;
250 return FEC_GROUP_UNUSABLE
;
253 static int decode_group(struct fecdec_group
*fg
, struct filter_node
*fn
)
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
);
260 if (u
== FEC_GROUP_UNUSABLE
) {
261 PARA_INFO_LOG("dropping unusable group %d\n", fg
->h
.group_num
);
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
);
269 pfd
->have_header
= 1;
271 if (u
== FEC_GROUP_USABLE_SKIP_HEADER
) {
272 i
= ROUND_UP(fg
->h
.audio_header_size
, fg
->h
.slice_bytes
)
274 PARA_DEBUG_LOG("skipping %d header slices\n", i
);
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
);
287 for (; i
< fg
->h
.data_slices_per_group
; i
++) {
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
);
299 * Read a fec header from a buffer.
301 * \param buf The buffer to write to.
302 * \param h The fec header to write.
304 static int read_fec_header(char *buf
, size_t len
, struct fec_header
*h
)
308 if (len
< FEC_HEADER_SIZE
)
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);
317 h
->group_num
= read_u32(buf
+ 10);
318 h
->group_bytes
= read_u32(buf
+ 14);
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);
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
)
335 struct fecdec_group
*fg
;
337 struct private_fecdec_data
*pfd
= fn
->private_data
;
339 if (h
->slice_bytes
> len
) /* can not use the thing, try to read more */
341 ret
= get_group(h
, pfd
, &fg
);
344 if (!add_slice(buf
, fg
))
346 if (group_complete(fg
)) {
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
);
354 ret
= decode_group(fg
, fn
);
361 static ssize_t
fecdec(char *buf
, size_t len
, struct filter_node
*fn
)
366 ret
= read_fec_header(buf
, len
, &h
);
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
,
375 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
378 return FEC_HEADER_SIZE
+ h
.slice_bytes
;
381 static void fecdec_close(struct filter_node
*fn
)
383 struct private_fecdec_data
*pfd
= fn
->private_data
;
384 struct fecdec_group
*fg
;
386 FOR_EACH_FECDEC_GROUP(fg
, pfd
)
391 free(fn
->private_data
);
392 fn
->private_data
= NULL
;
395 static void fecdec_open(struct filter_node
*fn
)
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
));
404 * The init function of the fecdec filter.
406 * \param f struct to initialize.
408 void fecdec_filter_init(struct filter
*f
)
411 f
->close
= fecdec_close
;
412 f
->open
= fecdec_open
;