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 that fec-decodes an audio stream. */
19 #include "portable_io.h"
24 * How many FEC groups to store in memory.
26 * Packet reordering requires to keep more than one FEC group in memory because
27 * slices belonging to the next FEC group may arrive before the current FEC group
30 #define NUM_FEC_GROUPS 3
32 /** Default size of the output buffer of the fecdec filter. */
33 #define FECDEC_DEFAULT_OUTBUF_SIZE (3 * 1024)
34 /** Maximal size of the output buffer of the fecdec filter. */
35 #define FECDEC_MAX_OUTBUF_SIZE (1024 * 1024)
37 /** Data read from the header of a slice. */
39 /** Total number of slices in this group. */
40 uint8_t slices_per_group
;
41 /** Number of slices needed to start decoding. */
42 uint8_t data_slices_per_group
;
43 /** Size of the ogg vorbis header (zero for mp3, aac). */
44 uint32_t audio_header_size
;
45 /** Number of the FEC group this slice belongs to. */
47 /** Size of the data in this FEC group. */
49 /** Number of this slice in the group. */
51 /** Used data bytes of this slice. */
53 /** Non-zero if this group is the beginning of the stream. */
55 /** Non-zero if this stream embedds audio headers into fec groups. */
56 uint8_t header_stream
;
60 * The status of one partially received FEC group.
63 /** The header read from the last slice. */
65 /** How many slices received so far. */
66 int num_received_slices
;
67 /** The size of the \a idx and the \a data arrays below. */
69 /** Array of indices of the received slices. */
71 /** Content of the received slices. */
76 * Data private to the fecdec filter.
78 struct private_fecdec_data
{
79 /** Used by the fec core code. */
80 struct fec_parms
*fec
;
81 /** Keeps track of what was received so far. */
82 struct fecdec_group groups
[NUM_FEC_GROUPS
];
83 /** Whether an audio file header was already received. */
85 /** Points to the first received group. */
86 struct fecdec_group
*first_complete_group
;
89 /** Iterate over all fecdec groups. */
90 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
91 (g) < (d)->groups + NUM_FEC_GROUPS; (g)++)
93 static int group_complete(struct fecdec_group
*fg
)
95 return fg
->num_received_slices
>= fg
->h
.data_slices_per_group
;
98 static int group_empty(struct fecdec_group
*fg
)
100 return fg
->num_received_slices
== 0;
103 static void clear_group(struct fecdec_group
*fg
)
107 for (i
= 0; i
< fg
->num_slices
; i
++) {
115 memset(&fg
->h
, 0, sizeof(struct fec_header
));
116 fg
->num_received_slices
= 0;
119 static int find_group(struct fec_header
*h
,
120 struct private_fecdec_data
*pfd
, struct fecdec_group
**result
)
122 struct fecdec_group
*fg
;
124 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
125 if (fg
->h
.group_num
!= h
->group_num
)
127 if (fg
->num_received_slices
== 0)
129 if (fg
->h
.slices_per_group
!= h
->slices_per_group
)
130 return -E_BAD_FEC_HEADER
;
131 if (fg
->h
.data_slices_per_group
!= h
->data_slices_per_group
)
132 return -E_BAD_FEC_HEADER
;
133 if (fg
->h
.group_bytes
!= h
->group_bytes
)
134 return -E_BAD_FEC_HEADER
;
142 static struct fecdec_group
*find_unused_group(struct private_fecdec_data
*pfd
)
144 struct fecdec_group
*fg
;
146 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
147 if (fg
->num_received_slices
== 0)
153 static struct fecdec_group
*try_to_free_group(struct private_fecdec_data
*pfd
)
155 struct fecdec_group
*fg
;
157 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
158 if (!group_complete(fg
))
161 * Don't clear the first complete group if it has not yet been
164 if (fg
== pfd
->first_complete_group
)
172 static struct fecdec_group
*free_oldest_group(struct private_fecdec_data
*pfd
)
174 struct fecdec_group
*fg
, *oldest
= NULL
;
176 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
177 if (!oldest
|| oldest
->h
.group_num
> fg
->h
.group_num
)
180 if (!group_complete(oldest
) && !group_empty(oldest
))
181 PARA_WARNING_LOG("Clearing incomplete group %d "
182 "(contains %d slices)\n", oldest
->h
.group_num
,
183 oldest
->num_received_slices
);
184 if (oldest
== pfd
->first_complete_group
)
185 pfd
->first_complete_group
= NULL
;
190 /* returns 1 if the group was found, 0 if not, negative on errors */
191 static int get_group(struct fec_header
*h
, struct private_fecdec_data
*pfd
,
192 struct fecdec_group
**result
)
194 struct fecdec_group
*fg
;
195 int ret
= find_group(h
, pfd
, &fg
);
199 if (ret
> 0) /* found group */
201 /* group not found */
202 fg
= find_unused_group(pfd
);
205 fg
= try_to_free_group(pfd
);
208 fg
= free_oldest_group(pfd
);
217 * returns 1 if slice was added, zero otherwise (because the group was already
218 * complete). In any case the number of received slices is being increased by
221 static int add_slice(char *buf
, struct fecdec_group
*fg
)
225 if (group_complete(fg
)) {
226 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
227 fg
->h
.group_num
, fg
->h
.slice_num
);
228 fg
->num_received_slices
++;
231 slice_num
= fg
->h
.slice_num
;
232 if (fg
->num_slices
== 0) {
233 fg
->num_slices
= fg
->h
.slices_per_group
;
234 fg
->idx
= para_malloc(fg
->num_slices
* sizeof(int));
235 fg
->data
= para_malloc(fg
->num_slices
* sizeof(unsigned char *));
236 memset(fg
->data
, 0, fg
->num_slices
* sizeof(unsigned char *));
238 r
= fg
->num_received_slices
;
239 fg
->idx
[r
] = slice_num
;
240 fg
->data
[r
] = para_malloc(fg
->h
.slice_bytes
);
241 memcpy(fg
->data
[r
], buf
, fg
->h
.slice_bytes
);
242 fg
->num_received_slices
++;
246 enum fec_group_usability
{
249 FEC_GROUP_USABLE_SKIP_HEADER
,
250 FEC_GROUP_USABLE_WITH_HEADER
253 static enum fec_group_usability
group_is_usable(struct fecdec_group
*fg
,
254 struct private_fecdec_data
*pfd
)
256 struct fec_header
*h
= &fg
->h
;
258 if (!h
->header_stream
)
259 return FEC_GROUP_USABLE
;
260 if (pfd
->have_header
) {
261 if (h
->audio_header_size
)
262 return FEC_GROUP_USABLE_SKIP_HEADER
;
263 return FEC_GROUP_USABLE
;
266 return FEC_GROUP_USABLE
;
267 if (fg
->h
.audio_header_size
)
268 return FEC_GROUP_USABLE_WITH_HEADER
;
269 return FEC_GROUP_UNUSABLE
;
272 static int decode_group(struct fecdec_group
*fg
, struct filter_node
*fn
)
274 int i
, ret
, sb
= fg
->h
.slice_bytes
;
275 size_t written
, need
;
276 struct private_fecdec_data
*pfd
= fn
->private_data
;
277 enum fec_group_usability u
= group_is_usable(fg
, pfd
);
279 if (u
== FEC_GROUP_UNUSABLE
) {
280 PARA_INFO_LOG("dropping unusable group %d\n", fg
->h
.group_num
);
283 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg
->h
.group_num
,
284 fg
->h
.data_slices_per_group
);
285 ret
= fec_decode(pfd
->fec
, fg
->data
, fg
->idx
, sb
);
288 pfd
->have_header
= 1;
290 if (u
== FEC_GROUP_USABLE_SKIP_HEADER
) {
291 i
= ROUND_UP(fg
->h
.audio_header_size
, fg
->h
.slice_bytes
)
293 PARA_DEBUG_LOG("skipping %d header slices\n", i
);
295 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
296 fg
->h
.group_num
, fg
->h
.group_bytes
,
297 fg
->h
.data_slices_per_group
* sb
);
298 need
= fn
->loaded
+ (fg
->h
.data_slices_per_group
- i
)* sb
;
299 if (need
> fn
->bufsize
) {
300 fn
->bufsize
= PARA_MAX(fn
->bufsize
* 2, need
);
301 if (fn
->bufsize
> FECDEC_MAX_OUTBUF_SIZE
)
302 return -E_FECDEC_OVERRUN
;
303 PARA_INFO_LOG("increasing fec buf to %zu\n", fn
->bufsize
);
304 fn
->buf
= para_realloc(fn
->buf
, fn
->bufsize
);
306 if (u
== FEC_GROUP_USABLE_WITH_HEADER
) {
307 PARA_INFO_LOG("writing audio file header\n");
309 for (i
= 0; i
< fg
->h
.data_slices_per_group
; i
++) {
311 if (written
>= fg
->h
.audio_header_size
)
313 if (sb
+ written
> fg
->h
.audio_header_size
)
314 n
= fg
->h
.audio_header_size
- written
;
315 memcpy(fn
->buf
+ fn
->loaded
, fg
->data
[i
], n
);
321 for (; i
< fg
->h
.data_slices_per_group
; i
++) {
323 if (n
+ written
> fg
->h
.group_bytes
)
324 n
= fg
->h
.group_bytes
- written
;
325 memcpy(fn
->buf
+ fn
->loaded
, fg
->data
[i
], n
);
333 * Read a fec header from a buffer.
335 * \param buf The buffer to write to.
336 * \param h The fec header to write.
338 static int read_fec_header(char *buf
, size_t len
, struct fec_header
*h
)
342 if (len
< FEC_HEADER_SIZE
)
344 magic
= read_u32(buf
);
345 if (magic
!= FEC_MAGIC
)
346 return -E_BAD_FEC_HEADER
;
347 h
->slices_per_group
= read_u8(buf
+ 4);
348 h
->data_slices_per_group
= read_u8(buf
+ 5);
349 h
->audio_header_size
= read_u32(buf
+ 6);
351 h
->group_num
= read_u32(buf
+ 10);
352 h
->group_bytes
= read_u32(buf
+ 14);
354 h
->slice_num
= read_u8(buf
+ 18);
355 h
->slice_bytes
= read_u16(buf
+ 20);
356 h
->bos
= read_u8(buf
+ 22);
357 h
->header_stream
= read_u8(buf
+ 23);
358 if (!memcmp(buf
, FEC_EOF_PACKET
, FEC_EOF_PACKET_LEN
))
359 return -E_FECDEC_EOF
;
360 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
361 // h->group_num, h->slice_num, h->slices_per_group);
365 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
366 static int dispatch_slice(char *buf
, size_t len
, struct fec_header
*h
,
367 struct filter_node
*fn
)
369 struct fecdec_group
*fg
;
371 struct private_fecdec_data
*pfd
= fn
->private_data
;
373 if (h
->slice_bytes
> len
) /* can not use the thing, try to read more */
375 ret
= get_group(h
, pfd
, &fg
);
378 if (!add_slice(buf
, fg
)) /* group already complete */
380 if (!group_complete(fg
))
382 /* this slice completed the group */
385 /* it's either the first or the second complete group */
386 if (!pfd
->first_complete_group
) { /* it's the first group */
387 enum fec_group_usability u
= group_is_usable(fg
, pfd
);
388 assert(u
!= FEC_GROUP_USABLE_SKIP_HEADER
);
389 if (u
== FEC_GROUP_UNUSABLE
) /* forget it */
391 pfd
->first_complete_group
= fg
; /* remember it */
394 /* we have two complete groups, let's go */
395 k
= h
->data_slices_per_group
;
396 n
= h
->slices_per_group
;
397 PARA_NOTICE_LOG("init fec (%d, %d)\n", k
, n
);
398 ret
= fec_new(k
, n
, &pfd
->fec
);
401 /* decode and clear the first group */
402 ret
= decode_group(pfd
->first_complete_group
, fn
);
405 clear_group(pfd
->first_complete_group
);
406 pfd
->first_complete_group
= NULL
;
408 ret
= decode_group(fg
, fn
);
414 static ssize_t
fecdec(char *buf
, size_t len
, struct filter_node
*fn
)
419 ret
= read_fec_header(buf
, len
, &h
);
423 return -E_BAD_SLICE_SIZE
;
424 if (h
.slice_num
> h
.slices_per_group
)
425 return -E_BAD_SLICE_NUM
;
426 ret
= dispatch_slice(buf
+ FEC_HEADER_SIZE
, len
- FEC_HEADER_SIZE
,
428 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
431 return FEC_HEADER_SIZE
+ h
.slice_bytes
;
434 static void fecdec_close(struct filter_node
*fn
)
436 struct private_fecdec_data
*pfd
= fn
->private_data
;
437 struct fecdec_group
*fg
;
439 FOR_EACH_FECDEC_GROUP(fg
, pfd
)
444 free(fn
->private_data
);
445 fn
->private_data
= NULL
;
448 static void fecdec_open(struct filter_node
*fn
)
450 struct private_fecdec_data
*pfd
;
451 fn
->bufsize
= FECDEC_DEFAULT_OUTBUF_SIZE
;
452 fn
->buf
= para_malloc(fn
->bufsize
);
453 pfd
= para_calloc(sizeof(*pfd
));
454 fn
->private_data
= pfd
;
459 * The init function of the fecdec filter.
461 * \param f struct to initialize.
463 void fecdec_filter_init(struct filter
*f
)
466 f
->close
= fecdec_close
;
467 f
->open
= fecdec_open
;