499c0a88931d1712bff7c3b57fef5fa75c075be8
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 (128 * 1024)
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. */
52 * The status of one partially received FEC group.
55 /** The header read from the last slice. */
57 /** How many slices received so far. */
58 int num_received_slices
;
59 /** The size of the \a idx and the \a data arrays below. */
61 /** Array of indices of the received slices. */
63 /** Content of the received slices. */
68 * Data private to the fecdec filter.
70 struct private_fecdec_data
{
71 /** Used by the fec core code. */
72 struct fec_parms
*fec
;
73 /** Keeps track of what was received so far. */
74 struct fecdec_group groups
[NUM_FEC_GROUPS
];
77 /** Iterate over all fecdec groups. */
78 #define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
79 (g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
81 static int group_complete(struct fecdec_group
*fg
)
83 return fg
->num_received_slices
>= fg
->h
.data_slices_per_group
;
86 static int group_empty(struct fecdec_group
*fg
)
88 return fg
->num_received_slices
== 0;
91 static void clear_group(struct fecdec_group
*fg
)
95 for (i
= 0; i
< fg
->num_slices
; i
++) {
103 memset(&fg
->h
, 0, sizeof(struct fec_header
));
104 fg
->num_received_slices
= 0;
107 static int find_group(struct fec_header
*h
,
108 struct private_fecdec_data
*pfd
, struct fecdec_group
**result
)
110 struct fecdec_group
*fg
;
112 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
113 if (fg
->h
.group_num
!= h
->group_num
)
115 if (fg
->h
.slices_per_group
!= h
->slices_per_group
)
117 if (fg
->h
.data_slices_per_group
!= h
->data_slices_per_group
)
125 static struct fecdec_group
*find_unused_group(struct private_fecdec_data
*pfd
)
127 struct fecdec_group
*fg
;
129 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
130 if (fg
->num_received_slices
== 0)
136 static struct fecdec_group
*try_to_free_group(struct private_fecdec_data
*pfd
)
138 struct fecdec_group
*fg
;
140 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
141 if (!group_complete(fg
))
149 static struct fecdec_group
*free_oldest_group(struct private_fecdec_data
*pfd
)
151 struct fecdec_group
*fg
, *oldest
= NULL
;
153 FOR_EACH_FECDEC_GROUP(fg
, pfd
) {
154 if (!oldest
|| oldest
->h
.group_num
> fg
->h
.group_num
)
157 if (!group_complete(oldest
) && !group_empty(oldest
))
158 PARA_WARNING_LOG("Clearing incomplete group %d "
159 "(contains %d slices)\n", fg
->h
.group_num
,
160 fg
->num_received_slices
);
165 /* returns 1 if the group was found, 0 if not, negative on errors */
166 static int get_group(struct fec_header
*h
, struct private_fecdec_data
*pfd
,
167 struct fecdec_group
**result
)
169 struct fecdec_group
*fg
;
170 int ret
= find_group(h
, pfd
, &fg
);
174 if (ret
> 0) /* found group */
176 /* group not found */
177 fg
= find_unused_group(pfd
);
180 fg
= try_to_free_group(pfd
);
183 fg
= free_oldest_group(pfd
);
192 * returns 1 if slice was added, zero otherwise (because the group was already
193 * complete). In any case the number of received slices is being increased by
196 static int add_slice(char *buf
, struct fecdec_group
*fg
)
200 if (group_complete(fg
)) {
201 PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
203 fg
->num_received_slices
++;
206 slice_num
= fg
->h
.slice_num
;
207 if (fg
->num_slices
== 0) {
208 fg
->num_slices
= fg
->h
.slices_per_group
;
209 fg
->idx
= malloc(fg
->num_slices
* sizeof(int));
210 fg
->data
= malloc(fg
->num_slices
* sizeof(unsigned char *));
211 memset(fg
->data
, 0, fg
->num_slices
* sizeof(unsigned char *));
213 r
= fg
->num_received_slices
;
214 fg
->idx
[r
] = slice_num
;
215 fg
->data
[r
] = malloc(fg
->h
.slice_bytes
);
216 memcpy(fg
->data
[r
], buf
, fg
->h
.slice_bytes
);
217 fg
->num_received_slices
++;
221 static int decode_group(struct fecdec_group
*fg
, struct filter_node
*fn
)
223 int i
, ret
, sb
= fg
->h
.slice_bytes
;
225 struct private_fecdec_data
*pfd
= fn
->private_data
;
227 ret
= fec_decode(pfd
->fec
, fg
->data
, fg
->idx
, sb
);
230 PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
231 fg
->h
.group_num
, fg
->h
.group_bytes
,
232 fg
->h
.data_slices_per_group
* sb
);
233 for (i
= 0; i
< fg
->h
.data_slices_per_group
; i
++) {
235 if (n
+ written
> fg
->h
.group_bytes
)
236 n
= fg
->h
.group_bytes
- written
;
237 if (fn
->loaded
+ n
> fn
->bufsize
)
238 return -E_FECDEC_OVERRUN
;
239 memcpy(fn
->buf
+ fn
->loaded
, fg
->data
[i
], n
);
247 * Read a fec header from a buffer.
249 * \param buf The buffer to write to.
250 * \param h The fec header to write.
252 static int read_fec_header(char *buf
, size_t len
, struct fec_header
*h
)
256 if (len
< FEC_HEADER_SIZE
)
258 magic
= read_u32(buf
);
259 if (magic
!= FEC_MAGIC
)
260 return -E_BAD_FEC_HEADER
;
261 h
->slices_per_group
= read_u8(buf
+ 4);
262 h
->data_slices_per_group
= read_u8(buf
+ 5);
263 h
->audio_header_size
= read_u32(buf
+ 6);
265 h
->group_num
= read_u32(buf
+ 10);
266 h
->group_bytes
= read_u32(buf
+ 14);
268 h
->slice_num
= read_u8(buf
+ 18);
269 h
->slice_bytes
= read_u16(buf
+ 20);
270 if (!h
->group_bytes
&& & h
->slice_bytes
)
271 return -E_FECDEC_EOF
;
272 // PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
273 // h->group_num, h->slice_num, h->slices_per_group);
277 /* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
278 static int dispatch_slice(char *buf
, size_t len
, struct fec_header
*h
,
279 struct filter_node
*fn
)
281 struct fecdec_group
*fg
;
283 struct private_fecdec_data
*pfd
= fn
->private_data
;
285 if (h
->slice_bytes
> len
) /* can not use the thing, try to read more */
287 ret
= get_group(h
, pfd
, &fg
);
290 if (!add_slice(buf
, fg
))
292 if (group_complete(fg
)) {
294 int k
= h
->data_slices_per_group
, n
= h
->slices_per_group
;
295 PARA_NOTICE_LOG("init fec (%d, %d)\n", k
, n
);
296 ret
= fec_new(k
, n
, &pfd
->fec
);
300 ret
= decode_group(fg
, fn
);
307 static ssize_t
fecdec(char *buf
, size_t len
, struct filter_node
*fn
)
312 ret
= read_fec_header(buf
, len
, &h
);
315 if (h
.slice_bytes
> fn
->bufsize
)
316 return -E_BAD_SLICE_SIZE
;
317 if (h
.slice_num
> h
.slices_per_group
)
318 return -E_BAD_SLICE_NUM
;
319 ret
= dispatch_slice(buf
+ FEC_HEADER_SIZE
, len
- FEC_HEADER_SIZE
,
321 //PARA_INFO_LOG("ret: %d, len: %d, slice_bytes: %d\n", ret, len, h.slice_bytes);
324 return FEC_HEADER_SIZE
+ h
.slice_bytes
;
327 static void fecdec_close(struct filter_node
*fn
)
329 struct private_fecdec_data
*pfd
= fn
->private_data
;
330 struct fecdec_group
*fg
;
332 FOR_EACH_FECDEC_GROUP(fg
, pfd
)
336 free(fn
->private_data
);
337 fn
->private_data
= NULL
;
340 static void fecdec_open(struct filter_node
*fn
)
342 fn
->bufsize
= FECDEC_OUTBUF_SIZE
;
343 fn
->buf
= para_malloc(fn
->bufsize
);
344 fn
->private_data
= para_calloc(sizeof(struct private_fecdec_data
));
349 * The init function of the fecdec filter.
351 * \param f struct to initialize.
353 void fecdec_filter_init(struct filter
*f
)
356 f
->close
= fecdec_close
;
357 f
->open
= fecdec_open
;