Commit 54f11e39 authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont

RTP: compute delay jitter (not used yet) and fix timeout

parent e9dc5e25
......@@ -136,11 +136,13 @@ int rtp_add_type (demux_t *demux, rtp_session_t *ses, const rtp_pt_t *pt)
/** State for an RTP source */
struct rtp_source_t
{
mtime_t expiry; /* inactivation date */
uint32_t ssrc;
uint32_t jitter; /* interarrival delay jitter estimate */
mtime_t last_rx; /* last received packet local timestamp */
uint32_t last_ts; /* last received packet RTP timestamp */
uint16_t bad_seq; /* tentatively next expected sequence for resync */
uint16_t max_seq; /* next expected sequence */
uint32_t jitter; /* interarrival delay jitter estimate */
uint16_t last_seq; /* sequence of the last dequeued packet */
block_t *blocks; /* re-ordered blocks queue */
......@@ -161,6 +163,7 @@ rtp_source_create (demux_t *demux, const rtp_session_t *session,
return NULL;
source->ssrc = ssrc;
source->jitter = 0;
source->max_seq = source->bad_seq = init_seq;
source->last_seq = init_seq - 1;
source->blocks = NULL;
......@@ -196,6 +199,12 @@ static inline uint16_t rtp_seq (const block_t *block)
return GetWBE (block->p_buffer + 2);
}
static inline uint32_t rtp_timestamp (const block_t *block)
{
assert (block->i_buffer >= 12);
return GetDWBE (block->p_buffer + 4);
}
/**
* Receives an RTP packet and queues it.
* @param demux VLC demux object
......@@ -239,7 +248,7 @@ rtp_receive (demux_t *demux, rtp_session_t *session, block_t *block)
}
/* RTP source garbage collection */
if (tmp->expiry < now)
if ((tmp->last_rx + (p_sys->timeout * CLOCK_FREQ)) < now)
{
rtp_source_destroy (demux, session, tmp);
if (--session->srcc > 0)
......@@ -267,7 +276,22 @@ rtp_receive (demux_t *demux, rtp_session_t *session, block_t *block)
goto drop;
tab[session->srcc++] = src;
/* Cannot compute jitter yet */
}
else if (session->ptc > 0)
{
/* Recompute jitter estimate. That is computed from the RTP timestamps
* and the system clock. It is independent of RTP sequence. */
/* FIXME: payload types have the same frequency? */
uint32_t freq = session->ptv[0].frequency;
uint32_t ts = rtp_timestamp (block);
int64_t d = ((now - src->last_rx) * freq) / CLOCK_FREQ;
d -= ts - src->last_ts;
if (d < 0) d = -d;
src->jitter += ((d - src->jitter) + 8) >> 4;
}
src->last_rx = now;
src->last_ts = rtp_timestamp (block);
/* Be optimistic for the first packet. Certain codec, such as Vorbis
* do not like loosing the first packet(s), so we cannot just wait
......@@ -369,7 +393,7 @@ rtp_decode (demux_t *demux, const rtp_session_t *session, rtp_source_t *src)
* Otherwise it would be impossible to compute consistent timestamps. */
/* FIXME: handle timestamp wrap properly */
/* TODO: sync multiple sources sanely... */
const uint32_t timestamp = GetDWBE (block->p_buffer + 4);
const uint32_t timestamp = rtp_timestamp (block);
block->i_pts = UINT64_C(1) * CLOCK_FREQ * timestamp / pt->frequency;
/* CSRC count */
......
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