* Licensed under the GPL v2. For licencing details see COPYING.
*/
-/** \file fecdec_filter.c A filter fec-decodes an audio stream. */
+/** \file fecdec_filter.c A filter that fec-decodes an audio stream. */
#include <dirent.h>
#include "para.h"
*/
#define NUM_FEC_GROUPS 3
-/** Size of the output buffer of the fecdec filter. */
-#define FECDEC_OUTBUF_SIZE (1024 * 1024) /* FIXME: This has to depend on the fec params */
+/** 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 {
unsigned char **data;
};
+/**
+ * The fecdec filter defers decoding of the first group until the first slice
+ * of the next group was received. This avoids buffer underruns in subsequent
+ * filters of the filter chain.
+ */
+enum group_completion_status {
+ /** No complete group received so far. */
+ GCS_NO_COMPLETE_GROUP,
+ /** First group received, but not yet decoded. */
+ GCS_FIRST_GROUP_COMPLETE,
+ /** At least one complete group decoded. */
+ GCS_FIRST_GROUP_DECODED,
+};
+
/**
* Data private to the fecdec filter.
*/
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;
+ /** See \ref group_completion_status. */
+ unsigned completion_status;
+ /** Points to the first received group. */
+ struct fecdec_group *first_complete_group;
};
/** 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;
}
FOR_EACH_FECDEC_GROUP(fg, pfd) {
if (!group_complete(fg))
continue;
+ /*
+ * Don't clear the first complete group if it has not yet been
+ * decoded.
+ */
+ if (pfd->completion_status == GCS_FIRST_GROUP_COMPLETE
+ && pfd->first_complete_group == fg)
+ continue;
clear_group(fg);
return fg;
}
}
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);
+ assert(pfd->completion_status != GCS_FIRST_GROUP_COMPLETE
+ || oldest != pfd->first_complete_group);
clear_group(oldest);
return oldest;
}
int r, slice_num;
if (group_complete(fg)) {
- PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
- fg->h.slice_num);
+ PARA_DEBUG_LOG("group %d complete, ignoring slice %d\n",
+ fg->h.group_num, fg->h.slice_num);
fg->num_received_slices++;
return 0;
}
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);
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,
+ 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)
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);
+ 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;
struct filter_node *fn)
{
struct fecdec_group *fg;
- int ret;
+ int ret, k, n;
struct private_fecdec_data *pfd = fn->private_data;
if (h->slice_bytes > len) /* can not use the thing, try to read more */
if (!add_slice(buf, fg))
return 1;
if (group_complete(fg)) {
- if (!pfd->fec) {
- int k = h->data_slices_per_group, n = h->slices_per_group;
- PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
- ret = fec_new(k, n, &pfd->fec);
- if (ret < 0)
- return ret;
+ if (pfd->completion_status == GCS_NO_COMPLETE_GROUP) {
+ pfd->completion_status = GCS_FIRST_GROUP_COMPLETE;
+ pfd->first_complete_group = fg;
+ return 1;
}
+ assert(pfd->fec);
ret = decode_group(fg, fn);
if (ret < 0)
return ret;
+ return 1;
}
+ if (pfd->completion_status == GCS_NO_COMPLETE_GROUP)
+ return 1;
+ if (pfd->completion_status == GCS_FIRST_GROUP_DECODED)
+ return 1;
+ if (fg == pfd->first_complete_group)
+ return 1;
+ assert(!pfd->fec);
+ k = h->data_slices_per_group;
+ n = h->slices_per_group;
+ PARA_NOTICE_LOG("init fec (%d, %d)\n", k, n);
+ ret = fec_new(k, n, &pfd->fec);
+ if (ret < 0)
+ return ret;
+ ret = decode_group(pfd->first_complete_group, fn);
+ if (ret < 0)
+ return ret;
+ pfd->completion_status = GCS_FIRST_GROUP_DECODED;
return 1;
}
ret = read_fec_header(buf, len, &h);
if (ret <= 0)
return ret;
- if (!h.slice_bytes || 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;
+ struct private_fecdec_data *pfd;
+ fn->bufsize = FECDEC_DEFAULT_OUTBUF_SIZE;
fn->buf = para_malloc(fn->bufsize);
- fn->private_data = para_calloc(sizeof(struct private_fecdec_data));
+ pfd = para_calloc(sizeof(*pfd));
+ pfd->completion_status = GCS_NO_COMPLETE_GROUP;
+ fn->private_data = pfd;
fn->loaded = 0;
}
projects / paraslash.git / blobdiff