* Licensed under the GPL v2. For licencing details see COPYING.
*/
-/** \file fecdev_filter.c A filter fec-decodes an audio stream. */
+/** \file fecdec_filter.c A filter fec-decodes an audio stream. */
#include <dirent.h>
#include "para.h"
#include "fec.h"
#include "fd.h"
+/**
+ * How many FEC groups to store in memory.
+ *
+ * Packet reordering requires to keep more than one FEC group in memory because
+ * slices belonging to the next FEC group may arrive before the current FEC group
+ * is complete.
+ */
#define NUM_FEC_GROUPS 3
-#define INPUT_BUFFER_SIZE 16384
-/** size of the output buffer */
-#define FECDEC_OUTBUF_SIZE 81920
+/** Default size of the output buffer of the fecdec filter. */
+#define FECDEC_DEFAULT_OUTBUF_SIZE (16 * 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 {
+ /** Total number of slices in this group. */
uint8_t slices_per_group;
+ /** Number of slices needed to start decoding. */
uint8_t data_slices_per_group;
+ /** Size of the ogg vorbis header (zero for mp3, aac). */
uint32_t audio_header_size;
-
+ /** Number of the FEC group this slice belongs to. */
uint32_t group_num;
+ /** Size of the data in this FEC group. */
uint32_t group_bytes;
-
+ /** Number of this slice in the group. */
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_group {
+/**
+ * The status of one partially received FEC group.
+ */
+struct fecdec_group {
+ /** The header read from the last slice. */
struct fec_header h;
+ /** How many slices received so far. */
int num_received_slices;
+ /** The size of the \a idx and the \a data arrays below. */
int num_slices;
+ /** Array of indices of the received slices. */
int *idx;
+ /** Content of the received slices. */
unsigned char **data;
};
+/**
+ * Data private to the fecdec filter.
+ */
struct private_fecdec_data {
+ /** Used by the fec core code. */
struct fec_parms *fec;
- struct fec_group groups[NUM_FEC_GROUPS];
+ /** Keeps track of what was received so far. */
+ struct fecdec_group groups[NUM_FEC_GROUPS];
+ int have_header;
};
-#define FOR_EACH_FEC_GROUP(g, d) for (g = (d)->groups; \
+/** Iterate over all fecdec groups. */
+#define FOR_EACH_FECDEC_GROUP(g, d) for (g = (d)->groups; \
(g) - (d)->groups < NUM_FEC_GROUPS; (g)++)
-#define UNUSED_GROUP_NUM 0xffffffff
-
-static int group_complete(struct fec_group *fg)
+static int group_complete(struct fecdec_group *fg)
{
- if (fg->h.group_num == UNUSED_GROUP_NUM)
- return 0;
- //PARA_INFO_LOG("received slices: %u, slices per group: %u\n", fg->num_received_slices, fg->h.data_slices_per_group);
return fg->num_received_slices >= fg->h.data_slices_per_group;
}
-static int group_empty(struct fec_group *fg)
+static int group_empty(struct fecdec_group *fg)
{
return fg->num_received_slices == 0;
}
-static void clear_group(struct fec_group *fg)
+static void clear_group(struct fecdec_group *fg)
{
int i;
- if (!group_complete(fg) && !group_empty(fg))
- PARA_WARNING_LOG("Clearing incomplete group %d "
- "(contains %d slices)\n", fg->h.group_num,
- fg->num_received_slices);
for (i = 0; i < fg->num_slices; i++) {
free(fg->data[i]);
fg->data[i] = NULL;
fg->num_slices = 0;
memset(&fg->h, 0, sizeof(struct fec_header));
fg->num_received_slices = 0;
- fg->h.group_num = UNUSED_GROUP_NUM;
}
static int find_group(struct fec_header *h,
- struct private_fecdec_data *pfd, struct fec_group **result)
+ struct private_fecdec_data *pfd, struct fecdec_group **result)
{
- struct fec_group *fg;
+ struct fecdec_group *fg;
- FOR_EACH_FEC_GROUP(fg, pfd) {
+ FOR_EACH_FECDEC_GROUP(fg, pfd) {
if (fg->h.group_num != h->group_num)
continue;
+ if (fg->h.slices_per_group != h->slices_per_group)
+ continue;
+ if (fg->h.data_slices_per_group != h->data_slices_per_group)
+ continue;
*result = fg;
return 1;
}
return 0;
}
-static struct fec_group *find_unused_group(struct private_fecdec_data *pfd)
+static struct fecdec_group *find_unused_group(struct private_fecdec_data *pfd)
{
- struct fec_group *fg;
+ struct fecdec_group *fg;
- FOR_EACH_FEC_GROUP(fg, pfd) {
+ FOR_EACH_FECDEC_GROUP(fg, pfd) {
if (fg->num_received_slices == 0)
return fg;
}
return NULL;
}
-static struct fec_group *try_to_free_group(struct private_fecdec_data *pfd)
+static struct fecdec_group *try_to_free_group(struct private_fecdec_data *pfd)
{
- struct fec_group *fg;
+ struct fecdec_group *fg;
- FOR_EACH_FEC_GROUP(fg, pfd) {
+ FOR_EACH_FECDEC_GROUP(fg, pfd) {
if (!group_complete(fg))
continue;
clear_group(fg);
return NULL;
}
-static struct fec_group *free_oldest_group(struct private_fecdec_data *pfd)
+static struct fecdec_group *free_oldest_group(struct private_fecdec_data *pfd)
{
- struct fec_group *fg, *oldest = NULL;
+ struct fecdec_group *fg, *oldest = NULL;
- FOR_EACH_FEC_GROUP(fg, pfd) {
+ FOR_EACH_FECDEC_GROUP(fg, pfd) {
if (!oldest || oldest->h.group_num > fg->h.group_num)
oldest = 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);
clear_group(oldest);
return oldest;
}
+/* returns 1 if the group was found, 0 if not, negative on errors */
static int get_group(struct fec_header *h, struct private_fecdec_data *pfd,
- struct fec_group **result)
+ struct fecdec_group **result)
{
- struct fec_group *fg;
+ struct fecdec_group *fg;
int ret = find_group(h, pfd, &fg);
if (ret < 0)
/* group not found */
fg = find_unused_group(pfd);
if (fg)
- goto update_header;
+ goto success;
fg = try_to_free_group(pfd);
if (fg)
- goto update_header;
+ goto success;
fg = free_oldest_group(pfd);
-update_header:
- fg->h = *h;
+ ret = 0;
success:
+ fg->h = *h;
*result = fg;
- return 1;
+ return ret;
}
-static int add_slice(char *buf, struct fec_group *fg)
+/*
+ * returns 1 if slice was added, zero otherwise (because the group was already
+ * complete). In any case the number of received slices is being increased by
+ * one.
+ */
+static int add_slice(char *buf, struct fecdec_group *fg)
{
int r, slice_num;
- if (group_complete(fg))
+ if (group_complete(fg)) {
+ PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
+ fg->h.slice_num);
+ fg->num_received_slices++;
return 0;
+ }
slice_num = fg->h.slice_num;
if (fg->num_slices == 0) {
fg->num_slices = fg->h.slices_per_group;
return 1;
}
-static int decode_group(struct fec_group *fg, struct filter_node *fn)
+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;
}
+/* returns 1 if we used the buffer, 0 if we didn't, negative on errors */
static int dispatch_slice(char *buf, size_t len, struct fec_header *h,
struct filter_node *fn)
{
- struct fec_group *fg;
+ struct fecdec_group *fg;
int ret;
struct private_fecdec_data *pfd = fn->private_data;
ret = get_group(h, pfd, &fg);
if (ret < 0)
return ret;
- if (group_complete(fg)) {
- PARA_DEBUG_LOG("group complete, ignoring slice %d\n",
- h->slice_num);
+ if (!add_slice(buf, fg))
return 1;
- }
- fg->h = *h;
- ret = add_slice(buf, fg);
- if (ret < 0)
- return ret;
if (group_complete(fg)) {
if (!pfd->fec) {
int k = h->data_slices_per_group, n = 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 > INPUT_BUFFER_SIZE)
+ if (!h.slice_bytes || h.slice_bytes > fn->bufsize)
return -E_BAD_SLICE_SIZE;
if (h.slice_num > h.slices_per_group)
return -E_BAD_SLICE_NUM;
static void fecdec_close(struct filter_node *fn)
{
struct private_fecdec_data *pfd = fn->private_data;
- struct fec_group *fg;
+ struct fecdec_group *fg;
- FOR_EACH_FEC_GROUP(fg, pfd)
+ FOR_EACH_FECDEC_GROUP(fg, pfd)
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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