2 * Copyright (C) 2009-2011 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 /** Bitmap of received slices. */
65 uint8_t received_slices
[32];
66 /** The size of the \a idx and the \a data arrays below. */
68 /** Array of indices of the received slices. */
70 /** Content of the received slices. */
75 * Data private to the fecdec filter.
77 struct private_fecdec_data
{
78 /** Used by the fec core code. */
79 struct fec_parms
*fec
;
80 /** Keeps track of what was received so far. */
81 struct fecdec_group groups
[NUM_FEC_GROUPS
];
82 /** Whether an audio file header was already received. */
84 /** Points to the first received group. */
85 struct fecdec_group
*first_complete_group
;
86 struct btr_pool
*btrp
;
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
++)
111 memset(fg
, 0, sizeof(*fg
));
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
))
156 * Don't clear the first complete group if it has not yet been
159 if (fg
== pfd
->first_complete_group
)
167 static struct fecdec_group
*free_oldest_group(struct private_fecdec_data
*pfd
)
169 struct fecdec_group
*fg
, *oldest
= NULL
;
171 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
172 if (!oldest
|| oldest
->h
.group_num
> fg
->h
.group_num
)
175 if (!group_complete(oldest
) && !group_empty(oldest
))
176 PARA_WARNING_LOG("Clearing incomplete group %d "
177 "(contains %d slices)\n", oldest
->h
.group_num
,
178 oldest
->num_received_slices
);
179 if (oldest
== pfd
->first_complete_group
)
180 pfd
->first_complete_group
= NULL
;
185 /* returns 1 if the group was found, 0 if not, negative on errors */
186 static int get_group(struct fec_header
*h
, struct private_fecdec_data
*pfd
,
187 struct fecdec_group
**result
)
189 struct fecdec_group
*fg
;
190 int ret
= find_group(h
, pfd
, &fg
);
194 if (ret
> 0) /* found group */
196 /* group not found */
197 fg
= find_unused_group(pfd
);
200 fg
= try_to_free_group(pfd
);
203 fg
= free_oldest_group(pfd
);
211 static bool test_and_set_slice_bit(struct fecdec_group
*fg
, uint8_t slice_num
)
213 uint8_t *p
= fg
->received_slices
+ slice_num
/ 8, old
= *p
;
215 *p
|= 1 << (slice_num
% 8);
220 * returns 1 if slice was added, zero otherwise (because the group was already
221 * complete or a slice has been received twice).
223 static int add_slice(char *buf
, struct fecdec_group
*fg
)
226 uint8_t slice_num
= fg
->h
.slice_num
;
228 if (group_complete(fg
)) {
229 PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
230 fg
->h
.group_num
, slice_num
);
233 if (fg
->num_slices
== 0) {
234 fg
->num_slices
= fg
->h
.slices_per_group
;
235 fg
->idx
= para_malloc(fg
->num_slices
* sizeof(int));
236 fg
->data
= para_calloc(fg
->num_slices
* sizeof(unsigned char *));
238 r
= fg
->num_received_slices
;
239 /* Check if we already have this slice. */
240 if (test_and_set_slice_bit(fg
, slice_num
)) {
241 PARA_INFO_LOG("ignoring duplicate slice %d:%d\n", fg
->h
.group_num
,
245 fg
->idx
[r
] = slice_num
;
246 fg
->data
[r
] = para_malloc(fg
->h
.slice_bytes
);
247 memcpy(fg
->data
[r
], buf
, fg
->h
.slice_bytes
);
248 fg
->num_received_slices
++;
253 * The different states of a complete FEC group.
255 * Even if a FEC group has been received successfully, it probably can not be
256 * used right away because some streams (ogg, wma) need to receive an audio
257 * file header before decoding can start.
259 enum fec_group_usability
{
260 /** Drop the group (because we did not receive the header yet). */
262 /** Use all data in the group. */
264 /** Use the group, but drop its audio file header. */
265 FEC_GROUP_USABLE_SKIP_HEADER
,
266 /** Use the group, including its header. */
267 FEC_GROUP_USABLE_WITH_HEADER
270 static enum fec_group_usability
group_is_usable(struct fecdec_group
*fg
,
271 struct private_fecdec_data
*pfd
)
273 struct fec_header
*h
= &fg
->h
;
275 if (!h
->header_stream
)
276 return FEC_GROUP_USABLE
;
277 if (pfd
->have_header
) {
278 if (h
->audio_header_size
)
279 return FEC_GROUP_USABLE_SKIP_HEADER
;
280 return FEC_GROUP_USABLE
;
283 return FEC_GROUP_USABLE
;
284 if (fg
->h
.audio_header_size
)
285 return FEC_GROUP_USABLE_WITH_HEADER
;
286 return FEC_GROUP_UNUSABLE
;
289 static int decode_group(struct fecdec_group
*fg
, struct filter_node
*fn
)
291 int i
, ret
, sb
= fg
->h
.slice_bytes
;
292 size_t written
, need
;
293 struct private_fecdec_data
*pfd
= fn
->private_data
;
294 enum fec_group_usability u
= group_is_usable(fg
, pfd
);
295 char *buf
= NULL
, *p
;
297 if (u
== FEC_GROUP_UNUSABLE
) {
298 PARA_INFO_LOG("dropping unusable group %d\n", fg
->h
.group_num
);
301 PARA_DEBUG_LOG("decoding group %d (%d slices)\n", fg
->h
.group_num
,
302 fg
->h
.data_slices_per_group
);
303 ret
= fec_decode(pfd
->fec
, fg
->data
, fg
->idx
, sb
);
306 pfd
->have_header
= 1;
308 if (u
== FEC_GROUP_USABLE_SKIP_HEADER
) {
309 i
= DIV_ROUND_UP(fg
->h
.audio_header_size
, fg
->h
.slice_bytes
);
310 PARA_DEBUG_LOG("skipping %d header slices\n", i
);
312 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
313 fg
->h
.group_num
, fg
->h
.group_bytes
,
314 fg
->h
.data_slices_per_group
* sb
);
315 need
= (fg
->h
.data_slices_per_group
- i
) * sb
;
316 if (need
> btr_pool_unused(pfd
->btrp
))
317 return -E_FECDEC_OVERRUN
;
318 btr_pool_get_buffer(pfd
->btrp
, &buf
);
320 if (u
== FEC_GROUP_USABLE_WITH_HEADER
) {
321 PARA_INFO_LOG("writing audio file header\n");
323 for (i
= 0; i
< fg
->h
.data_slices_per_group
; i
++) {
325 if (written
>= fg
->h
.audio_header_size
)
327 if (sb
+ written
> fg
->h
.audio_header_size
)
328 n
= fg
->h
.audio_header_size
- written
;
329 btr_copy(fg
->data
[i
], n
, pfd
->btrp
, fn
->btrn
);
335 for (; i
< fg
->h
.data_slices_per_group
; i
++) {
337 if (n
+ written
> fg
->h
.group_bytes
)
338 n
= fg
->h
.group_bytes
- written
;
339 btr_copy(fg
->data
[i
], n
, pfd
->btrp
, fn
->btrn
);
347 * Read a fec header from a buffer.
349 * \param buf The buffer to write to.
350 * \param h The fec header to write.
352 static int read_fec_header(char *buf
, size_t len
, struct fec_header
*h
)
356 if (len
< FEC_HEADER_SIZE
)
358 magic
= read_u32(buf
);
359 if (magic
!= FEC_MAGIC
)
360 return -E_BAD_FEC_HEADER
;
361 h
->slices_per_group
= read_u8(buf
+ 4);
362 h
->data_slices_per_group
= read_u8(buf
+ 5);
363 h
->audio_header_size
= read_u32(buf
+ 6);
365 h
->group_num
= read_u32(buf
+ 10);
366 h
->group_bytes
= read_u32(buf
+ 14);
368 h
->slice_num
= read_u8(buf
+ 18);
369 h
->slice_bytes
= read_u16(buf
+ 20);
370 h
->bos
= read_u8(buf
+ 22);
371 h
->header_stream
= read_u8(buf
+ 23);
372 if (!memcmp(buf
, FEC_EOF_PACKET
, FEC_EOF_PACKET_LEN
))
373 return -E_FECDEC_EOF
;
374 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
375 // h->group_num, h->slice_num, h->slices_per_group);
379 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
380 static int dispatch_slice(char *buf
, size_t len
, struct fec_header
*h
,
381 struct filter_node
*fn
)
383 struct fecdec_group
*fg
;
385 struct private_fecdec_data
*pfd
= fn
->private_data
;
387 if (h
->slice_bytes
> len
) { /* can not use the thing, try to read more */
388 fn
->min_iqs
= h
->slice_bytes
+ FEC_HEADER_SIZE
;
391 ret
= get_group(h
, pfd
, &fg
);
394 if (!add_slice(buf
, fg
)) /* group already complete */
396 if (!group_complete(fg
))
398 /* this slice completed the group */
401 /* it's either the first or the second complete group */
402 if (!pfd
->first_complete_group
) { /* it's the first group */
403 enum fec_group_usability u
= group_is_usable(fg
, pfd
);
404 assert(u
!= FEC_GROUP_USABLE_SKIP_HEADER
);
405 if (u
== FEC_GROUP_UNUSABLE
) /* forget it */
407 pfd
->first_complete_group
= fg
; /* remember it */
410 /* we have two complete groups, let's go */
411 k
= h
->data_slices_per_group
;
412 n
= h
->slices_per_group
;
413 PARA_NOTICE_LOG("init fec (%d, %d)\n", k
, n
);
414 ret
= fec_new(k
, n
, &pfd
->fec
);
417 pfd
->btrp
= btr_pool_new("fecdec", 64 * 1024);
418 /* decode and clear the first group */
419 ret
= decode_group(pfd
->first_complete_group
, fn
);
422 clear_group(pfd
->first_complete_group
);
423 pfd
->first_complete_group
= NULL
;
425 ret
= decode_group(fg
, fn
);
431 static void fecdec_close(struct filter_node
*fn
)
433 struct private_fecdec_data
*pfd
= fn
->private_data
;
434 struct fecdec_group
*fg
;
436 FOR_EACH_FECDEC_GROUP(fg
, pfd
)
439 btr_pool_free(pfd
->btrp
);
440 free(fn
->private_data
);
441 fn
->private_data
= NULL
;
444 static void fecdec_post_select(__a_unused
struct sched
*s
, struct task
*t
)
446 struct filter_node
*fn
= container_of(t
, struct filter_node
, task
);
447 struct btr_node
*btrn
= fn
->btrn
;
454 ret
= btr_node_status(btrn
, fn
->min_iqs
, BTR_NT_INTERNAL
);
457 btr_merge(btrn
, fn
->min_iqs
);
458 len
= btr_next_buffer(btrn
, &buf
);
459 ret
= read_fec_header(buf
, len
, &h
);
462 ret
= -E_BAD_SLICE_SIZE
;
465 ret
= -E_BAD_SLICE_NUM
;
466 if (h
.slice_num
> h
.slices_per_group
)
468 ret
= dispatch_slice(buf
+ FEC_HEADER_SIZE
, len
- FEC_HEADER_SIZE
,
470 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
473 btr_consume(btrn
, FEC_HEADER_SIZE
+ h
.slice_bytes
);
478 btr_remove_node(btrn
);
481 static void fecdec_open(struct filter_node
*fn
)
483 struct private_fecdec_data
*pfd
;
484 pfd
= para_calloc(sizeof(*pfd
));
485 fn
->private_data
= pfd
;
486 fn
->min_iqs
= FEC_HEADER_SIZE
;
490 * The init function of the fecdec filter.
492 * \param f Struct to initialize.
494 void fecdec_filter_init(struct filter
*f
)
496 f
->close
= fecdec_close
;
497 f
->open
= fecdec_open
;
498 f
->pre_select
= generic_filter_pre_select
;
499 f
->post_select
= fecdec_post_select
;