/** \file fecdec_filter.c A filter fec-decodes an audio stream. */
+#include <regex.h>
+
#include <dirent.h>
#include "para.h"
#include "error.h"
*/
#define NUM_FEC_GROUPS 3
-/** Size of the output buffer of the fecdec filter. */
-#define FECDEC_OUTBUF_SIZE (128 * 1024)
+/** Default size of the output buffer of the fecdec filter. */
+#define FECDEC_DEFAULT_OUTBUF_SIZE (3 * 1024)
+/** Maximal size of the output buffer of the fecdec filter. */
+#define FECDEC_MAX_OUTBUF_SIZE (1024 * 1024)
/** Data read from the header of a slice. */
struct fec_header {
uint8_t slice_num;
/** Used data bytes of this slice. */
uint16_t slice_bytes;
+ /** Non-zero if this group is the beginning of the stream. */
+ uint8_t bos;
+ /** Non-zero if this stream embedds audio headers into fec groups. */
+ uint8_t header_stream;
};
/**
struct fec_parms *fec;
/** Keeps track of what was received so far. */
struct fecdec_group groups[NUM_FEC_GROUPS];
+ /** Whether an audio file header was already received. */
+ int have_header;
};
/** Iterate over all fecdec groups. */
FOR_EACH_FECDEC_GROUP(fg, pfd) {
if (fg->h.group_num != h->group_num)
continue;
+ if (fg->num_received_slices == 0)
+ goto success;
if (fg->h.slices_per_group != h->slices_per_group)
- continue;
+ return -E_BAD_FEC_HEADER;
if (fg->h.data_slices_per_group != h->data_slices_per_group)
- continue;
+ return -E_BAD_FEC_HEADER;
+ if (fg->h.group_bytes != h->group_bytes)
+ return -E_BAD_FEC_HEADER;
+success:
*result = fg;
return 1;
}
}
if (!group_complete(oldest) && !group_empty(oldest))
PARA_WARNING_LOG("Clearing incomplete group %d "
- "(contains %d slices)\n", fg->h.group_num,
- fg->num_received_slices);
+ "(contains %d slices)\n", oldest->h.group_num,
+ oldest->num_received_slices);
clear_group(oldest);
return oldest;
}
return 1;
}
+enum fec_group_usability {
+ FEC_GROUP_UNUSABLE,
+ FEC_GROUP_USABLE,
+ FEC_GROUP_USABLE_SKIP_HEADER,
+};
+
+static enum fec_group_usability group_is_usable(struct fecdec_group *fg,
+ struct private_fecdec_data *pfd)
+{
+ struct fec_header *h = &fg->h;
+
+ if (!h->header_stream)
+ return FEC_GROUP_USABLE;
+ if (pfd->have_header) {
+ if (h->audio_header_size)
+ return FEC_GROUP_USABLE_SKIP_HEADER;
+ return FEC_GROUP_USABLE;
+ }
+ if (fg->h.bos)
+ return FEC_GROUP_USABLE;
+ if (fg->h.audio_header_size)
+ return FEC_GROUP_USABLE;
+ return FEC_GROUP_UNUSABLE;
+}
+
static int decode_group(struct fecdec_group *fg, struct filter_node *fn)
{
int i, ret, sb = fg->h.slice_bytes;
- size_t written = 0;
+ size_t written = 0, need;
struct private_fecdec_data *pfd = fn->private_data;
+ enum fec_group_usability u = group_is_usable(fg, pfd);
+ if (u == FEC_GROUP_UNUSABLE) {
+ PARA_INFO_LOG("dropping unusable group %d\n", fg->h.group_num);
+ return 0;
+ }
+ PARA_DEBUG_LOG("decoding group %d %d slices\n", fg->h.group_num,
+ fg->h.data_slices_per_group);
ret = fec_decode(pfd->fec, fg->data, fg->idx, sb);
if (ret < 0)
return ret;
+ pfd->have_header = 1;
+ i = 0;
+ if (u == FEC_GROUP_USABLE_SKIP_HEADER) {
+ i = ROUND_UP(fg->h.audio_header_size, fg->h.slice_bytes)
+ / fg->h.slice_bytes;
+ PARA_DEBUG_LOG("skipping %d header slices\n", i);
+ }
PARA_DEBUG_LOG("writing group %d (%d/%d decoded data bytes)\n",
fg->h.group_num, fg->h.group_bytes,
fg->h.data_slices_per_group * sb);
- for (i = 0; i < fg->h.data_slices_per_group; i++) {
+ need = fn->loaded + (fg->h.data_slices_per_group - i)* sb;
+ if (need > fn->bufsize) {
+ fn->bufsize = PARA_MAX(fn->bufsize * 2, need);
+ if (fn->bufsize > FECDEC_MAX_OUTBUF_SIZE)
+ return -E_FECDEC_OVERRUN;
+ PARA_INFO_LOG("increasing fec buf to %zu\n", fn->bufsize);
+ fn->buf = para_realloc(fn->buf, fn->bufsize);
+ }
+ for (; i < fg->h.data_slices_per_group; i++) {
size_t n = sb;
if (n + written > fg->h.group_bytes)
n = fg->h.group_bytes - written;
- if (fn->loaded + n > fn->bufsize)
- return -E_FECDEC_OVERRUN;
memcpy(fn->buf + fn->loaded, fg->data[i], n);
fn->loaded += n;
written += n;
h->slice_num = read_u8(buf + 18);
h->slice_bytes = read_u16(buf + 20);
- if (!h->group_bytes && & h->slice_bytes)
+ h->bos = read_u8(buf + 22);
+ h->header_stream = read_u8(buf + 23);
+ if (!memcmp(buf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
return -E_FECDEC_EOF;
// PARA_DEBUG_LOG("group %u, slize %u, slices per group: %u\n",
// h->group_num, h->slice_num, h->slices_per_group);
return 1;
}
-static int fecdec(char *buf, size_t len, struct filter_node *fn)
+static ssize_t fecdec(char *buf, size_t len, struct filter_node *fn)
{
int ret;
struct fec_header h;
ret = read_fec_header(buf, len, &h);
if (ret <= 0)
return ret;
- if (h.slice_bytes > fn->bufsize)
+ if (!h.slice_bytes)
return -E_BAD_SLICE_SIZE;
if (h.slice_num > h.slices_per_group)
return -E_BAD_SLICE_NUM;
clear_group(fg);
free(fn->buf);
fn->buf = NULL;
+ fec_free(pfd->fec);
free(fn->private_data);
fn->private_data = NULL;
}
static void fecdec_open(struct filter_node *fn)
{
- fn->bufsize = FECDEC_OUTBUF_SIZE;
+ fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
fn->buf = para_malloc(fn->bufsize);
fn->private_data = para_calloc(sizeof(struct private_fecdec_data));
fn->loaded = 0;
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