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. */
18 #include "buffer_tree.h"
21 #include "portable_io.h"
26 * How many FEC groups to store in memory.
28 * Packet reordering requires to keep more than one FEC group in memory because
29 * slices belonging to the next FEC group may arrive before the current FEC group
32 #define NUM_FEC_GROUPS 3
34 /** Data read from the header of a slice. */
36 /** Total number of slices in this group. */
37 uint8_t slices_per_group
;
38 /** Number of slices needed to start decoding. */
39 uint8_t data_slices_per_group
;
40 /** Size of the ogg vorbis/wma header (zero for mp3, aac). */
41 uint32_t audio_header_size
;
42 /** Number of the FEC group this slice belongs to. */
44 /** Size of the data in this FEC group. */
46 /** Number of this slice in the group. */
48 /** Used data bytes of this slice. */
50 /** Non-zero if this group is the beginning of the stream. */
52 /** Non-zero if this stream embedds audio headers into fec groups. */
53 uint8_t header_stream
;
57 * The status of one partially received FEC group.
60 /** The header read from the last slice. */
62 /** How many slices received so far. */
63 int num_received_slices
;
64 /** The size of the \a idx and the \a data arrays below. */
66 /** Array of indices of the received slices. */
68 /** Content of the received slices. */
73 * Data private to the fecdec filter.
75 struct private_fecdec_data
{
76 /** Used by the fec core code. */
77 struct fec_parms
*fec
;
78 /** Keeps track of what was received so far. */
79 struct fecdec_group groups
[NUM_FEC_GROUPS
];
80 /** Whether an audio file header was already received. */
82 /** Points to the first received group. */
83 struct fecdec_group
*first_complete_group
;
84 struct btr_pool
*btrp
;
87 /** Iterate over all fecdec groups. */
88 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
89 (g) < (d)->groups + NUM_FEC_GROUPS; (g)++)
91 static int group_complete(struct fecdec_group
*fg
)
93 return fg
->num_received_slices
>= fg
->h
.data_slices_per_group
;
96 static int group_empty(struct fecdec_group
*fg
)
98 return fg
->num_received_slices
== 0;
101 static void clear_group(struct fecdec_group
*fg
)
105 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
++;
247 * The different states of a complete FEC group.
249 * Even if a FEC group has been received successfully, it probably can not be
250 * used right away because some streams (ogg, wma) need to receive an audio
251 * file header before decoding can start.
253 enum fec_group_usability
{
254 /** Drop the group (because we did not receive the header yet). */
256 /** Use all data in the group. */
258 /** Use the group, but drop its audio file header. */
259 FEC_GROUP_USABLE_SKIP_HEADER
,
260 /** Use the group, including its header. */
261 FEC_GROUP_USABLE_WITH_HEADER
264 static enum fec_group_usability
group_is_usable(struct fecdec_group
*fg
,
265 struct private_fecdec_data
*pfd
)
267 struct fec_header
*h
= &fg
->h
;
269 if (!h
->header_stream
)
270 return FEC_GROUP_USABLE
;
271 if (pfd
->have_header
) {
272 if (h
->audio_header_size
)
273 return FEC_GROUP_USABLE_SKIP_HEADER
;
274 return FEC_GROUP_USABLE
;
277 return FEC_GROUP_USABLE
;
278 if (fg
->h
.audio_header_size
)
279 return FEC_GROUP_USABLE_WITH_HEADER
;
280 return FEC_GROUP_UNUSABLE
;
283 static int decode_group(struct fecdec_group
*fg
, struct filter_node
*fn
)
285 int i
, ret
, sb
= fg
->h
.slice_bytes
;
286 size_t written
, need
;
287 struct private_fecdec_data
*pfd
= fn
->private_data
;
288 enum fec_group_usability u
= group_is_usable(fg
, pfd
);
289 char *buf
= NULL
, *p
;
291 if (u
== FEC_GROUP_UNUSABLE
) {
292 PARA_INFO_LOG("dropping unusable group %d\n", fg
->h
.group_num
);
295 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg
->h
.group_num
,
296 fg
->h
.data_slices_per_group
);
297 ret
= fec_decode(pfd
->fec
, fg
->data
, fg
->idx
, sb
);
300 pfd
->have_header
= 1;
302 if (u
== FEC_GROUP_USABLE_SKIP_HEADER
) {
303 i
= ROUND_UP(fg
->h
.audio_header_size
, fg
->h
.slice_bytes
)
305 PARA_DEBUG_LOG("skipping %d header slices\n", i
);
307 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
308 fg
->h
.group_num
, fg
->h
.group_bytes
,
309 fg
->h
.data_slices_per_group
* sb
);
310 need
= (fg
->h
.data_slices_per_group
- i
) * sb
;
311 if (need
> btr_pool_unused(pfd
->btrp
))
312 return -E_FECDEC_OVERRUN
;
313 btr_pool_get_buffer(pfd
->btrp
, &buf
);
315 if (u
== FEC_GROUP_USABLE_WITH_HEADER
) {
316 PARA_INFO_LOG("writing audio file header\n");
318 for (i
= 0; i
< fg
->h
.data_slices_per_group
; i
++) {
320 if (written
>= fg
->h
.audio_header_size
)
322 if (sb
+ written
> fg
->h
.audio_header_size
)
323 n
= fg
->h
.audio_header_size
- written
;
324 btr_copy(fg
->data
[i
], n
, pfd
->btrp
, fn
->btrn
);
330 for (; i
< fg
->h
.data_slices_per_group
; i
++) {
332 if (n
+ written
> fg
->h
.group_bytes
)
333 n
= fg
->h
.group_bytes
- written
;
334 btr_copy(fg
->data
[i
], n
, pfd
->btrp
, fn
->btrn
);
342 * Read a fec header from a buffer.
344 * \param buf The buffer to write to.
345 * \param h The fec header to write.
347 static int read_fec_header(char *buf
, size_t len
, struct fec_header
*h
)
351 if (len
< FEC_HEADER_SIZE
)
353 magic
= read_u32(buf
);
354 if (magic
!= FEC_MAGIC
)
355 return -E_BAD_FEC_HEADER
;
356 h
->slices_per_group
= read_u8(buf
+ 4);
357 h
->data_slices_per_group
= read_u8(buf
+ 5);
358 h
->audio_header_size
= read_u32(buf
+ 6);
360 h
->group_num
= read_u32(buf
+ 10);
361 h
->group_bytes
= read_u32(buf
+ 14);
363 h
->slice_num
= read_u8(buf
+ 18);
364 h
->slice_bytes
= read_u16(buf
+ 20);
365 h
->bos
= read_u8(buf
+ 22);
366 h
->header_stream
= read_u8(buf
+ 23);
367 if (!memcmp(buf
, FEC_EOF_PACKET
, FEC_EOF_PACKET_LEN
))
368 return -E_FECDEC_EOF
;
369 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
370 // h->group_num, h->slice_num, h->slices_per_group);
374 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
375 static int dispatch_slice(char *buf
, size_t len
, struct fec_header
*h
,
376 struct filter_node
*fn
)
378 struct fecdec_group
*fg
;
380 struct private_fecdec_data
*pfd
= fn
->private_data
;
382 if (h
->slice_bytes
> len
) { /* can not use the thing, try to read more */
383 fn
->min_iqs
= h
->slice_bytes
+ FEC_HEADER_SIZE
;
386 ret
= get_group(h
, pfd
, &fg
);
389 if (!add_slice(buf
, fg
)) /* group already complete */
391 if (!group_complete(fg
))
393 /* this slice completed the group */
396 /* it's either the first or the second complete group */
397 if (!pfd
->first_complete_group
) { /* it's the first group */
398 enum fec_group_usability u
= group_is_usable(fg
, pfd
);
399 assert(u
!= FEC_GROUP_USABLE_SKIP_HEADER
);
400 if (u
== FEC_GROUP_UNUSABLE
) /* forget it */
402 pfd
->first_complete_group
= fg
; /* remember it */
405 /* we have two complete groups, let's go */
406 k
= h
->data_slices_per_group
;
407 n
= h
->slices_per_group
;
408 PARA_NOTICE_LOG("init fec (%d, %d)\n", k
, n
);
409 ret
= fec_new(k
, n
, &pfd
->fec
);
412 pfd
->btrp
= btr_pool_new("fecdec", 20 * k
* h
->slice_bytes
);
413 /* decode and clear the first group */
414 ret
= decode_group(pfd
->first_complete_group
, fn
);
417 clear_group(pfd
->first_complete_group
);
418 pfd
->first_complete_group
= NULL
;
420 ret
= decode_group(fg
, fn
);
426 static void fecdec_close(struct filter_node
*fn
)
428 struct private_fecdec_data
*pfd
= fn
->private_data
;
429 struct fecdec_group
*fg
;
431 FOR_EACH_FECDEC_GROUP(fg
, pfd
)
434 free(fn
->private_data
);
435 fn
->private_data
= NULL
;
438 static void fecdec_post_select(__a_unused
struct sched
*s
, struct task
*t
)
440 struct filter_node
*fn
= container_of(t
, struct filter_node
, task
);
441 struct btr_node
*btrn
= fn
->btrn
;
448 ret
= btr_node_status(btrn
, fn
->min_iqs
, BTR_NT_INTERNAL
);
451 btr_merge(btrn
, fn
->min_iqs
);
452 len
= btr_next_buffer(btrn
, &buf
);
453 ret
= read_fec_header(buf
, len
, &h
);
456 ret
= -E_BAD_SLICE_SIZE
;
459 ret
= -E_BAD_SLICE_NUM
;
460 if (h
.slice_num
> h
.slices_per_group
)
462 ret
= dispatch_slice(buf
+ FEC_HEADER_SIZE
, len
- FEC_HEADER_SIZE
,
464 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
467 btr_consume(btrn
, FEC_HEADER_SIZE
+ h
.slice_bytes
);
472 btr_remove_node(btrn
);
475 static void fecdec_open(struct filter_node
*fn
)
477 struct private_fecdec_data
*pfd
;
478 pfd
= para_calloc(sizeof(*pfd
));
479 fn
->private_data
= pfd
;
480 fn
->min_iqs
= FEC_HEADER_SIZE
;
484 * The init function of the fecdec filter.
486 * \param f Struct to initialize.
488 void fecdec_filter_init(struct filter
*f
)
490 f
->close
= fecdec_close
;
491 f
->open
= fecdec_open
;
492 f
->pre_select
= generic_filter_pre_select
;
493 f
->post_select
= fecdec_post_select
;