size_t header_len;
};
+/**
+ * The list of currently connected fec clients.
+ *
+ * Senders may use \ref vss_add_fec_client() to add entries to the list.
+ */
static struct list_head fec_client_list;
+/**
+ * Describes one slice of a FEC group.
+ *
+ * FEC slices directly correspond to the data packages sent by the paraslash
+ * senders that use FEC. Each slice is identified by its group number and its
+ * number within the group. All slices have the same size, but the last slice
+ * of the group may not be filled entirely.
+ */
struct fec_slice {
+ /** The slice number within the FEC group. */
uint8_t num;
+ /** The number of used bytes in this slice. */
uint16_t bytes;
};
+/**
+ * Data associated with one FEC group.
+ *
+ * A FEC group consists of a fixed number of slices and this number is given by
+ * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
+ * group contains a number of chunks of the current audio file.
+ */
struct fec_group {
+ /** The number of the FEC group. */
uint32_t num;
+ /** Number of bytes in this group. */
uint32_t bytes;
+ /** The first chunk of the current audio file belonging to the group. */
uint32_t first_chunk;
+ /** The number of chunks contained in this group. */
uint32_t num_chunks;
+ /** The time needed to play all chunks of the group. */
struct timeval duration;
+ /** When the first chunk was sent. */
struct timeval start;
+ /** \a The group duration divided by \a slices_per_group. */
struct timeval slice_duration;
};
+/**
+ * Describes one connected FEC client.
+ */
struct fec_client {
+ /** Parameters requested by the client. */
struct fec_client_parms *fcp;
+ /** Used by the core FEC code. */
struct fec_parms *parms;
+ /** The position of this client in the fec client list. */
struct list_head node;
+ /** When the first slice for this client was sent. */
struct timeval stream_start;
+ /** The first chunk sent to this FEC client. */
int first_stream_chunk;
+ /** Describes the current group. */
struct fec_group group;
+ /** Describes the current slice. */
struct fec_slice slice;
+ /** The data to be FEC-encoded (point to a region within the mapped audio file). */
const unsigned char **src_data;
+ /** Used for the last source pointer of the last group. */
unsigned char *extra_src_buf;
+ /** The size of the buffer for the extra source pointer. */
size_t extra_src_buf_size;
+ /** Contains FEC-encoded data. */
unsigned char *enc_buf;
+ /** Size of \a enc_buf. */
size_t enc_buf_size;
};
return &mmd->afd.afhi.chunk_tv;
}
-static void setup_fec_group(struct fec_client *fc, struct vss_task *vsst)
+/**
+ * Write a fec header to a buffer.
+ *
+ * \param buf The buffer to write to.
+ * \param h The fec header to write.
+ */
+static void write_fec_header(struct fec_client *fc)
+{
+ char *buf = (char *)fc->enc_buf;
+
+ write_u32(buf, FEC_MAGIC);
+
+ write_u8(buf + 4, fc->fcp->slices_per_group);
+ write_u8(buf + 5, fc->fcp->data_slices_per_group);
+ write_u32(buf + 6, (uint32_t)0); /* audio header len */
+
+ write_u32(buf + 10, fc->group.num);
+ write_u32(buf + 14, fc->group.bytes);
+
+ write_u8(buf + 18, fc->slice.num);
+ write_u16(buf + 20, fc->slice.bytes);
+ memset(buf + 22, 0, 11);
+}
+
+static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
{
- uint32_t num_bytes = 0, chunk_num, max_group_size, last_payload_size;
+ uint32_t max_group_size, last_payload_size;
int i, k = fc->fcp->data_slices_per_group;
- const char *start_buf = NULL;
+ size_t len;
+ const char *start_buf;
struct timeval tmp, *chunk_tv = vss_chunk_time();
assert(chunk_tv);
+ if (fc->first_stream_chunk < 0) {
+ fc->stream_start = *now;
+ fc->first_stream_chunk = mmd->current_chunk;
+ fc->group.first_chunk = mmd->current_chunk;
+ fc->group.num = 0;
+ } else {
+ fc->group.first_chunk += fc->group.num_chunks;
+ fc->group.num++;
+ }
+ if (fc->group.first_chunk >= mmd->afd.afhi.chunks_total)
+ return 0;
max_group_size = (fc->fcp->max_slice_bytes - FEC_HEADER_SIZE) * k;
- chunk_num = fc->group.first_chunk;
- for (;;) {
+ afh_get_chunk(fc->group.first_chunk, &mmd->afd.afhi, vsst->map,
+ &start_buf, &len);
+ for (i = fc->group.first_chunk, fc->group.bytes = 0;
+ i < mmd->afd.afhi.chunks_total; i++) {
const char *buf;
- size_t len;
- if (chunk_num >= mmd->afd.afhi.chunks_total)
+ afh_get_chunk(i, &mmd->afd.afhi, vsst->map, &buf, &len);
+ if (fc->group.bytes + len > max_group_size)
break;
- afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, &buf, &len);
- if (!start_buf)
- start_buf = buf;
- if (num_bytes + len > max_group_size)
- break;
- chunk_num++;
- num_bytes += len;
+ fc->group.bytes += len;
}
- assert(start_buf);
- fc->group.num_chunks = chunk_num - fc->group.first_chunk;
- fc->group.num++;
- fc->group.bytes = num_bytes;
+ fc->group.num_chunks = i - fc->group.first_chunk;
fc->slice.num = 0;
- fc->slice.bytes = ROUND_UP(num_bytes, k) / k;
+ fc->slice.bytes = ROUND_UP(fc->group.bytes, k) / k;
/* The last slice will not be fully used */
- last_payload_size = num_bytes % fc->slice.bytes;
+ last_payload_size = fc->group.bytes % fc->slice.bytes;
if (!last_payload_size)
last_payload_size = fc->slice.bytes;
- tv_scale(fc->group.num_chunks, chunk_tv, &fc->group.duration);
tv_scale(fc->group.first_chunk - fc->first_stream_chunk, chunk_tv,
&tmp);
tv_add(&fc->stream_start, &tmp, &fc->group.start);
+ if (fc->group.num) /* quick hack to avoid buffer underruns */
+ fc->group.start.tv_sec--;
+ tv_scale(fc->group.num_chunks, chunk_tv, &fc->group.duration);
tv_divide(fc->fcp->slices_per_group, &fc->group.duration,
&fc->group.slice_duration);
if (start_buf + k * fc->slice.bytes > vsst->map + mmd->size) {
/* can not use last slice as it goes beyond the map */
- if (fc->extra_src_buf_size < fc->slice.bytes)
+ if (fc->extra_src_buf_size < fc->slice.bytes) {
fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->slice.bytes);
+ fc->extra_src_buf_size = fc->slice.bytes;
+ }
memcpy(fc->extra_src_buf, start_buf + (k - 1) * fc->slice.bytes,
last_payload_size);
memset(fc->extra_src_buf + last_payload_size, 0,
fc->slice.bytes - last_payload_size);
fc->src_data[k - 1] = fc->extra_src_buf;
}
-
+ if (fc->enc_buf_size < fc->slice.bytes + FEC_HEADER_SIZE) {
+ fc->enc_buf_size = fc->slice.bytes + FEC_HEADER_SIZE;
+ fc->enc_buf = para_realloc(fc->enc_buf, fc->enc_buf_size);
+ }
+ PARA_INFO_LOG("FEC group %d: %d chunks (%d - %d), duration: %lums\n",
+ fc->group.num, fc->group.num_chunks, fc->group.first_chunk,
+ fc->group.first_chunk + fc->group.num_chunks - 1,
+ tv2ms(&fc->group.duration));
+ return 1;
}
-/**
- * Write a fec header to a buffer.
- *
- * \param buf The buffer to write to.
- * \param h The fec header to write.
- */
-static void write_fec_header(struct fec_client *fc)
+static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
{
- char *buf = (char *)fc->enc_buf;
-
- write_u32(buf, FEC_MAGIC);
-
- write_u8(buf + 4, fc->fcp->slices_per_group);
- write_u8(buf + 5, fc->fcp->data_slices_per_group);
- write_u32(buf + 6, (uint32_t)0); /* audio header len */
-
- write_u32(buf + 10, fc->group.num);
- write_u32(buf + 14, fc->group.bytes);
-
- write_u8(buf + 18, fc->slice.num);
- write_u16(buf + 20, fc->slice.bytes);
- memset(buf + 22, 0, 11);
+ if (fc->first_stream_chunk < 0 || fc->slice.num
+ == fc->fcp->slices_per_group) {
+ if (!setup_next_fec_group(fc, vsst))
+ return 0;
+ }
+ write_fec_header(fc);
+ fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
+ fc->slice.num, fc->slice.bytes);
+ return 1;
}
/**
* Return a buffer that marks the end of the stream.
*
+ * \param buf Result pointer.
* \return The length of the eof buffer.
*
* This is used for (multicast) udp streaming where closing the socket on the
return FEC_HEADER_SIZE;
}
-static void compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
-{
- if (fc->first_stream_chunk < 0) {
- fc->stream_start = *now;
- fc->first_stream_chunk = mmd->current_chunk;
- fc->group.first_chunk = mmd->current_chunk;
- fc->group.num = 0;
- setup_fec_group(fc, vsst);
- } else if (fc->slice.num == fc->fcp->slices_per_group) {
- fc->group.first_chunk += fc->group.num_chunks;
- setup_fec_group(fc, vsst);
-
- }
- if (fc->enc_buf_size < fc->slice.bytes + FEC_HEADER_SIZE) {
- fc->enc_buf_size = fc->slice.bytes + FEC_HEADER_SIZE;
- fc->enc_buf = para_realloc(fc->enc_buf, fc->enc_buf_size);
- }
- write_fec_header(fc);
- fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
- fc->slice.num, fc->slice.bytes);
-}
-
/**
* Add one entry to the list of active fec clients.
*
list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
if (!next_slice_is_due(fc, NULL))
continue;
- compute_next_fec_slice(fc, vsst);
+ if (!compute_next_fec_slice(fc, vsst))
+ continue;
PARA_DEBUG_LOG("sending %d:%d (%zu bytes)\n", fc->group.num,
fc->slice.num, fc->slice.bytes);
fc->fcp->send((char *)fc->enc_buf,
projects / paraslash.git / blobdiff