Commit fad7f0d5 authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont

RTP: reorder for better readability

parent e570b837
......@@ -376,80 +376,13 @@ drop:
}
static void
rtp_decode (demux_t *demux, const rtp_session_t *session, rtp_source_t *src)
{
block_t *block = src->blocks;
assert (block);
src->blocks = block->p_next;
block->p_next = NULL;
/* Discontinuity detection */
uint16_t delta_seq = rtp_seq (block) - (src->last_seq + 1);
if (delta_seq != 0)
{
if (delta_seq >= 0x8000)
{ /* Trash too late packets (and PIM Assert duplicates) */
msg_Dbg (demux, "ignoring late packet (sequence: %"PRIu16")",
rtp_seq (block));
goto drop;
}
msg_Warn (demux, "%"PRIu16" packet(s) lost", delta_seq);
block->i_flags |= BLOCK_FLAG_DISCONTINUITY;
}
src->last_seq = rtp_seq (block);
/* Match the payload type */
void *pt_data;
const rtp_pt_t *pt = rtp_find_ptype (session, src, block, &pt_data);
if (pt == NULL)
{
msg_Dbg (demux, "unknown payload (%"PRIu8")",
rtp_ptype (block));
goto drop;
}
/* Computes the PTS from the RTP timestamp and payload RTP frequency.
* DTS is unknown. Also, while the clock frequency depends on the payload
* format, a single source MUST only use payloads of a chosen frequency.
* Otherwise it would be impossible to compute consistent timestamps. */
const uint32_t timestamp = rtp_timestamp (block);
block->i_pts = src->ref_ntp
+ CLOCK_FREQ * (int32_t)(timestamp - src->ref_rtp) / pt->frequency;
/* TODO: proper inter-medias/sessions sync (using RTCP-SR) */
src->ref_ntp = block->i_pts;
src->ref_rtp = timestamp;
/* CSRC count */
size_t skip = 12u + (block->p_buffer[0] & 0x0F) * 4;
/* Extension header (ignored for now) */
if (block->p_buffer[0] & 0x10)
{
skip += 4;
if (block->i_buffer < skip)
goto drop;
skip += 4 * GetWBE (block->p_buffer + skip - 2);
}
if (block->i_buffer < skip)
goto drop;
block->p_buffer += skip;
block->i_buffer -= skip;
pt->decode (demux, pt_data, block);
return;
drop:
block_Release (block);
}
static void rtp_decode (demux_t *, const rtp_session_t *, rtp_source_t *);
/**
* Dequeues an RTP packet and pass it to decoder. Not cancellation-safe(?).
* Dequeues RTP packets and pass them to decoder. Not cancellation-safe(?).
* A packet is decoded if it is the next in sequence order, or if we have
* given up waiting on the missing packets (time out) from the last one
* already decoded.
*
* @param demux VLC demux object
* @param session RTP session receiving the packet
......@@ -527,3 +460,78 @@ bool rtp_dequeue (demux_t *demux, const rtp_session_t *session,
}
return pending;
}
/**
* Decodes one RTP packet.
*/
static void
rtp_decode (demux_t *demux, const rtp_session_t *session, rtp_source_t *src)
{
block_t *block = src->blocks;
assert (block);
src->blocks = block->p_next;
block->p_next = NULL;
/* Discontinuity detection */
uint16_t delta_seq = rtp_seq (block) - (src->last_seq + 1);
if (delta_seq != 0)
{
if (delta_seq >= 0x8000)
{ /* Trash too late packets (and PIM Assert duplicates) */
msg_Dbg (demux, "ignoring late packet (sequence: %"PRIu16")",
rtp_seq (block));
goto drop;
}
msg_Warn (demux, "%"PRIu16" packet(s) lost", delta_seq);
block->i_flags |= BLOCK_FLAG_DISCONTINUITY;
}
src->last_seq = rtp_seq (block);
/* Match the payload type */
void *pt_data;
const rtp_pt_t *pt = rtp_find_ptype (session, src, block, &pt_data);
if (pt == NULL)
{
msg_Dbg (demux, "unknown payload (%"PRIu8")",
rtp_ptype (block));
goto drop;
}
/* Computes the PTS from the RTP timestamp and payload RTP frequency.
* DTS is unknown. Also, while the clock frequency depends on the payload
* format, a single source MUST only use payloads of a chosen frequency.
* Otherwise it would be impossible to compute consistent timestamps. */
const uint32_t timestamp = rtp_timestamp (block);
block->i_pts = src->ref_ntp
+ CLOCK_FREQ * (int32_t)(timestamp - src->ref_rtp) / pt->frequency;
/* TODO: proper inter-medias/sessions sync (using RTCP-SR) */
src->ref_ntp = block->i_pts;
src->ref_rtp = timestamp;
/* CSRC count */
size_t skip = 12u + (block->p_buffer[0] & 0x0F) * 4;
/* Extension header (ignored for now) */
if (block->p_buffer[0] & 0x10)
{
skip += 4;
if (block->i_buffer < skip)
goto drop;
skip += 4 * GetWBE (block->p_buffer + skip - 2);
}
if (block->i_buffer < skip)
goto drop;
block->p_buffer += skip;
block->i_buffer -= skip;
pt->decode (demux, pt_data, block);
return;
drop:
block_Release (block);
}
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