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 /** Size of the output buffer of the fecdec filter. */
31 #define FECDEC_OUTBUF_SIZE (1024 * 1024) /* FIXME: This has to depend on the fec params */
33 /** Data read from the header of a slice. */
35 /** Total number of slices in this group. */
36 uint8_t slices_per_group
;
37 /** Number of slices needed to start decoding. */
38 uint8_t data_slices_per_group
;
39 /** Size of the ogg vorbis header (zero for mp3, aac). */
40 uint32_t audio_header_size
;
41 /** Number of the FEC group this slice belongs to. */
43 /** Size of the data in this FEC group. */
45 /** Number of this slice in the group. */
47 /** Used data bytes of this slice. */
49 /** Non-zero if this group is the beginning of the stream. */
51 /** Non-zero if this stream embedds audio headers into fec groups. */
52 uint8_t header_stream
;
56 * The status of one partially received FEC group.
59 /** The header read from the last slice. */
61 /** How many slices received so far. */
62 int num_received_slices
;
63 /** The size of the \a idx and the \a data arrays below. */
65 /** Array of indices of the received slices. */
67 /** Content of the received slices. */
72 * Data private to the fecdec filter.
74 struct private_fecdec_data
{
75 /** Used by the fec core code. */
76 struct fec_parms
*fec
;
77 /** Keeps track of what was received so far. */
78 struct fecdec_group groups
[NUM_FEC_GROUPS
];
82 /** Iterate over all fecdec groups. */
83 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
84 (g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
86 static int group_complete(struct fecdec_group
*fg
)
88 return fg
->num_received_slices
>= fg
->h
.data_slices_per_group
;
91 static int group_empty(struct fecdec_group
*fg
)
93 return fg
->num_received_slices
== 0;
96 static void clear_group(struct fecdec_group
*fg
)
100 for (i
= 0; i
< fg
->num_slices
; i
++) {
108 memset(&fg
->h
, 0, sizeof(struct fec_header
));
109 fg
->num_received_slices
= 0;
112 static int find_group(struct fec_header
*h
,
113 struct private_fecdec_data
*pfd
, struct fecdec_group
**result
)
115 struct fecdec_group
*fg
;
117 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
118 if (fg
->h
.group_num
!= h
->group_num
)
120 if (fg
->num_received_slices
== 0)
122 if (fg
->h
.slices_per_group
!= h
->slices_per_group
)
123 return -E_BAD_FEC_HEADER
;
124 if (fg
->h
.data_slices_per_group
!= h
->data_slices_per_group
)
125 return -E_BAD_FEC_HEADER
;
126 if (fg
->h
.group_bytes
!= h
->group_bytes
)
127 return -E_BAD_FEC_HEADER
;
135 static struct fecdec_group
*find_unused_group(struct private_fecdec_data
*pfd
)
137 struct fecdec_group
*fg
;
139 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
140 if (fg
->num_received_slices
== 0)
146 static struct fecdec_group
*try_to_free_group(struct private_fecdec_data
*pfd
)
148 struct fecdec_group
*fg
;
150 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
151 if (!group_complete(fg
))
159 static struct fecdec_group
*free_oldest_group(struct private_fecdec_data
*pfd
)
161 struct fecdec_group
*fg
, *oldest
= NULL
;
163 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
164 if (!oldest
|| oldest
->h
.group_num
> fg
->h
.group_num
)
167 if (!group_complete(oldest
) && !group_empty(oldest
))
168 PARA_WARNING_LOG("Clearing incomplete group %d "
169 "(contains %d slices)\n", oldest
->h
.group_num
,
170 oldest
->num_received_slices
);
175 /* returns 1 if the group was found, 0 if not, negative on errors */
176 static int get_group(struct fec_header
*h
, struct private_fecdec_data
*pfd
,
177 struct fecdec_group
**result
)
179 struct fecdec_group
*fg
;
180 int ret
= find_group(h
, pfd
, &fg
);
184 if (ret
> 0) /* found group */
186 /* group not found */
187 fg
= find_unused_group(pfd
);
190 fg
= try_to_free_group(pfd
);
193 fg
= free_oldest_group(pfd
);
202 * returns 1 if slice was added, zero otherwise (because the group was already
203 * complete). In any case the number of received slices is being increased by
206 static int add_slice(char *buf
, struct fecdec_group
*fg
)
210 if (group_complete(fg
)) {
211 PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
213 fg
->num_received_slices
++;
216 slice_num
= fg
->h
.slice_num
;
217 if (fg
->num_slices
== 0) {
218 fg
->num_slices
= fg
->h
.slices_per_group
;
219 fg
->idx
= malloc(fg
->num_slices
* sizeof(int));
220 fg
->data
= malloc(fg
->num_slices
* sizeof(unsigned char *));
221 memset(fg
->data
, 0, fg
->num_slices
* sizeof(unsigned char *));
223 r
= fg
->num_received_slices
;
224 fg
->idx
[r
] = slice_num
;
225 fg
->data
[r
] = malloc(fg
->h
.slice_bytes
);
226 memcpy(fg
->data
[r
], buf
, fg
->h
.slice_bytes
);
227 fg
->num_received_slices
++;
231 enum fec_group_usability
{
234 FEC_GROUP_USABLE_SKIP_HEADER
,
237 static enum fec_group_usability
group_is_usable(struct fecdec_group
*fg
,
238 struct private_fecdec_data
*pfd
)
240 struct fec_header
*h
= &fg
->h
;
242 if (!h
->header_stream
)
243 return FEC_GROUP_USABLE
;
244 if (pfd
->have_header
) {
245 if (h
->audio_header_size
)
246 return FEC_GROUP_USABLE_SKIP_HEADER
;
247 return FEC_GROUP_USABLE
;
250 return FEC_GROUP_USABLE
;
251 if (fg
->h
.audio_header_size
)
252 return FEC_GROUP_USABLE
;
253 return FEC_GROUP_UNUSABLE
;
256 static int decode_group(struct fecdec_group
*fg
, struct filter_node
*fn
)
258 int i
, ret
, sb
= fg
->h
.slice_bytes
;
260 struct private_fecdec_data
*pfd
= fn
->private_data
;
261 enum fec_group_usability u
= group_is_usable(fg
, pfd
);
263 if (u
== FEC_GROUP_UNUSABLE
) {
264 PARA_INFO_LOG("dropping unusable group %d\n", fg
->h
.group_num
);
267 PARA_DEBUG_LOG("decoding group %d %d slices\n", fg
->h
.group_num
,
268 fg
->h
.data_slices_per_group
);
269 ret
= fec_decode(pfd
->fec
, fg
->data
, fg
->idx
, sb
);
272 pfd
->have_header
= 1;
274 if (u
== FEC_GROUP_USABLE_SKIP_HEADER
) {
275 i
= ROUND_UP(fg
->h
.audio_header_size
, fg
->h
.slice_bytes
)
277 PARA_DEBUG_LOG("skipping %d header slices\n", i
);
279 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
280 fg
->h
.group_num
, fg
->h
.group_bytes
,
281 fg
->h
.data_slices_per_group
* sb
);
282 for (; i
< fg
->h
.data_slices_per_group
; i
++) {
284 if (n
+ written
> fg
->h
.group_bytes
)
285 n
= fg
->h
.group_bytes
- written
;
286 if (fn
->loaded
+ n
> fn
->bufsize
)
287 return -E_FECDEC_OVERRUN
;
288 memcpy(fn
->buf
+ fn
->loaded
, fg
->data
[i
], n
);
296 * Read a fec header from a buffer.
298 * \param buf The buffer to write to.
299 * \param h The fec header to write.
301 static int read_fec_header(char *buf
, size_t len
, struct fec_header
*h
)
305 if (len
< FEC_HEADER_SIZE
)
307 magic
= read_u32(buf
);
308 if (magic
!= FEC_MAGIC
)
309 return -E_BAD_FEC_HEADER
;
310 h
->slices_per_group
= read_u8(buf
+ 4);
311 h
->data_slices_per_group
= read_u8(buf
+ 5);
312 h
->audio_header_size
= read_u32(buf
+ 6);
314 h
->group_num
= read_u32(buf
+ 10);
315 h
->group_bytes
= read_u32(buf
+ 14);
317 h
->slice_num
= read_u8(buf
+ 18);
318 h
->slice_bytes
= read_u16(buf
+ 20);
319 h
->bos
= read_u8(buf
+ 22);
320 h
->header_stream
= read_u8(buf
+ 23);
321 if (!memcmp(buf
, FEC_EOF_PACKET
, FEC_EOF_PACKET_LEN
))
322 return -E_FECDEC_EOF
;
323 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
324 // h->group_num, h->slice_num, h->slices_per_group);
328 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
329 static int dispatch_slice(char *buf
, size_t len
, struct fec_header
*h
,
330 struct filter_node
*fn
)
332 struct fecdec_group
*fg
;
334 struct private_fecdec_data
*pfd
= fn
->private_data
;
336 if (h
->slice_bytes
> len
) /* can not use the thing, try to read more */
338 ret
= get_group(h
, pfd
, &fg
);
341 if (!add_slice(buf
, fg
))
343 if (group_complete(fg
)) {
345 int k
= h
->data_slices_per_group
, n
= h
->slices_per_group
;
346 PARA_NOTICE_LOG("init fec (%d, %d)\n", k
, n
);
347 ret
= fec_new(k
, n
, &pfd
->fec
);
351 ret
= decode_group(fg
, fn
);
358 static ssize_t
fecdec(char *buf
, size_t len
, struct filter_node
*fn
)
363 ret
= read_fec_header(buf
, len
, &h
);
367 return -E_BAD_SLICE_SIZE
;
368 if (h
.slice_num
> h
.slices_per_group
)
369 return -E_BAD_SLICE_NUM
;
370 ret
= dispatch_slice(buf
+ FEC_HEADER_SIZE
, len
- FEC_HEADER_SIZE
,
372 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
375 return FEC_HEADER_SIZE
+ h
.slice_bytes
;
378 static void fecdec_close(struct filter_node
*fn
)
380 struct private_fecdec_data
*pfd
= fn
->private_data
;
381 struct fecdec_group
*fg
;
383 FOR_EACH_FECDEC_GROUP(fg
, pfd
)
388 free(fn
->private_data
);
389 fn
->private_data
= NULL
;
392 static void fecdec_open(struct filter_node
*fn
)
394 fn
->bufsize
= FECDEC_OUTBUF_SIZE
;
395 fn
->buf
= para_malloc(fn
->bufsize
);
396 fn
->private_data
= para_calloc(sizeof(struct private_fecdec_data
));
401 * The init function of the fecdec filter.
403 * \param f struct to initialize.
405 void fecdec_filter_init(struct filter
*f
)
408 f
->close
= fecdec_close
;
409 f
->open
= fecdec_open
;