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rtcp.c
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/*! \file rtcp.c
* \author Lorenzo Miniero <[email protected]>
* \copyright GNU General Public License v3
* \brief RTCP processing
* \details Implementation (based on the oRTP structures) of the RTCP
* messages. RTCP messages coming through the server are parsed and,
* if needed (according to http://tools.ietf.org/html/draft-ietf-straw-b2bua-rtcp-00),
* fixed before they are sent to the peers (e.g., to fix SSRCs that may
* have been changed by the server). Methods to generate FIR messages
* and generate/cap REMB messages are provided as well.
*
* \ingroup protocols
* \ref protocols
*/
#include <math.h>
#include <stdlib.h>
#include <sys/time.h>
#include "debug.h"
#include "rtp.h"
#include "rtcp.h"
#include "utils.h"
int janus_rtcp_parse(janus_rtcp_context *ctx, char *packet, int len) {
return janus_rtcp_fix_ssrc(ctx, packet, len, 0, 0, 0);
}
guint32 janus_rtcp_get_sender_ssrc(char *packet, int len) {
if(packet == NULL || len == 0)
return 0;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return 0;
int pno = 0, total = len;
while(rtcp) {
pno++;
switch(rtcp->type) {
case RTCP_SR: {
/* SR, sender report */
janus_rtcp_sr *sr = (janus_rtcp_sr *)rtcp;
return ntohl(sr->ssrc);
}
case RTCP_RR: {
/* RR, receiver report */
janus_rtcp_rr *rr = (janus_rtcp_rr *)rtcp;
return ntohl(rr->ssrc);
}
case RTCP_RTPFB: {
/* RTPFB, Transport layer FB message (rfc4585) */
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
return ntohl(rtcpfb->ssrc);
}
case RTCP_PSFB: {
/* PSFB, Payload-specific FB message (rfc4585) */
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
return ntohl(rtcpfb->ssrc);
}
case RTCP_XR: {
/* XR, extended reports (rfc3611) */
janus_rtcp_xr *xr = (janus_rtcp_xr *)rtcp;
return ntohl(xr->ssrc);
}
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0) {
break;
}
total -= length*4+4;
if(total <= 0) {
break;
}
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return 0;
}
guint32 janus_rtcp_get_receiver_ssrc(char *packet, int len) {
if(packet == NULL || len == 0)
return 0;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return 0;
int pno = 0, total = len;
while(rtcp) {
pno++;
switch(rtcp->type) {
case RTCP_SR: {
/* SR, sender report */
janus_rtcp_sr *sr = (janus_rtcp_sr *)rtcp;
if(sr->header.rc > 0) {
return ntohl(sr->rb[0].ssrc);
}
break;
}
case RTCP_RR: {
/* RR, receiver report */
janus_rtcp_rr *rr = (janus_rtcp_rr *)rtcp;
if(rr->header.rc > 0) {
return ntohl(rr->rb[0].ssrc);
}
break;
}
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0) {
break;
}
total -= length*4+4;
if(total <= 0) {
break;
}
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return 0;
}
/* Helper to handle an incoming SR: triggered by a call to janus_rtcp_fix_ssrc with fixssrc=0 */
static void janus_rtcp_incoming_sr(janus_rtcp_context *ctx, janus_rtcp_sr *sr) {
if(ctx == NULL)
return;
/* Update the context with info on the monotonic time of last SR received */
ctx->lsr_ts = janus_get_monotonic_time();
/* Compute the last SR received as well */
uint64_t ntp = ntohl(sr->si.ntp_ts_msw);
ntp = (ntp << 32) | ntohl(sr->si.ntp_ts_lsw);
ctx->lsr = (ntp >> 16);
}
/* Link quality estimate filter coefficient */
#define LINK_QUALITY_FILTER_K 3.0
static double janus_rtcp_link_quality_filter(double last, double in) {
if (last == 0 || last != last) {
return in;
} else {
return (1.0 - 1.0/LINK_QUALITY_FILTER_K) * last + (1.0/LINK_QUALITY_FILTER_K) * in;
}
}
/* Update link quality stats based on RR */
static void janus_rtcp_rr_update_stats(rtcp_context *ctx, janus_report_block rb) {
int64_t ts = janus_get_monotonic_time();
int64_t delta_t = ts - ctx->rr_last_ts;
if(delta_t < 2*G_USEC_PER_SEC) {
return;
}
ctx->rr_last_ts = ts;
uint32_t total_lost = ntohl(rb.flcnpl) & 0x00FFFFFF;
if (ctx->rr_last_ehsnr != 0) {
uint32_t sent = g_atomic_int_get(&ctx->sent_packets_since_last_rr);
uint32_t expect = ntohl(rb.ehsnr) - ctx->rr_last_ehsnr;
int32_t nacks = g_atomic_int_get(&ctx->nack_count) - ctx->rr_last_nack_count;
double link_q = !sent ? 0 : 100.0 - (100.0 * nacks / (double)sent);
ctx->out_link_quality = janus_rtcp_link_quality_filter(ctx->out_link_quality, link_q);
int32_t lost = total_lost - ctx->rr_last_lost;
if(lost < 0) {
lost = 0;
}
double media_link_q = !expect ? 0 : 100.0 - (100.0 * lost / (double)expect);
ctx->out_media_link_quality = janus_rtcp_link_quality_filter(ctx->out_media_link_quality, media_link_q);
JANUS_LOG(LOG_HUGE, "Out link quality=%"SCNu32", media link quality=%"SCNu32"\n", janus_rtcp_context_get_out_link_quality(ctx), janus_rtcp_context_get_out_media_link_quality(ctx));
}
ctx->rr_last_ehsnr = ntohl(rb.ehsnr);
ctx->rr_last_lost = total_lost;
ctx->rr_last_nack_count = g_atomic_int_get(&ctx->nack_count);
g_atomic_int_set(&ctx->sent_packets_since_last_rr, 0);
}
/* Helper to handle an incoming RR: triggered by a call to janus_rtcp_fix_ssrc with fixssrc=0 */
static void janus_rtcp_incoming_rr(janus_rtcp_context *ctx, janus_rtcp_rr *rr) {
if(ctx == NULL)
return;
/* FIXME Check the Record Blocks */
if(rr->header.rc > 0) {
double jitter = (double)ntohl(rr->rb[0].jitter);
uint32_t fraction = ntohl(rr->rb[0].flcnpl) >> 24;
uint32_t total = ntohl(rr->rb[0].flcnpl) & 0x00FFFFFF;
JANUS_LOG(LOG_HUGE, "jitter=%f, fraction=%"SCNu32", loss=%"SCNu32"\n", jitter, fraction, total);
ctx->lost_remote = total;
ctx->jitter_remote = jitter;
janus_rtcp_rr_update_stats(ctx, rr->rb[0]);
/* FIXME Compute round trip time */
uint32_t lsr = ntohl(rr->rb[0].lsr);
uint32_t dlsr = ntohl(rr->rb[0].delay);
if(lsr == 0) /* Not enough info yet */
return;
struct timeval tv;
gettimeofday(&tv, NULL);
uint32_t s = tv.tv_sec + 2208988800u;
uint32_t u = tv.tv_usec;
uint32_t f = (u << 12) + (u << 8) - ((u * 3650) >> 6);
uint32_t ntp_ts_msw = s;
uint32_t ntp_ts_lsw = f;
uint64_t temp = ((uint64_t)ntp_ts_msw << 32 ) | ntp_ts_lsw;
uint32_t a = (uint32_t)(temp >> 16);
uint32_t rtt = a - lsr - dlsr;
uint32_t rtt_msw = (rtt & 0xFFFF0000) >> 16;
uint32_t rtt_lsw = rtt & 0x0000FFFF;
tv.tv_sec = rtt_msw;
tv.tv_usec = (rtt_lsw * 15625) >> 10;
ctx->rtt = tv.tv_sec*1000 + tv.tv_usec/1000; /* We need milliseconds */
JANUS_LOG(LOG_HUGE, "rtt=%"SCNu32"\n", ctx->rtt);
}
}
int janus_rtcp_fix_ssrc(janus_rtcp_context *ctx, char *packet, int len, int fixssrc, uint32_t newssrcl, uint32_t newssrcr) {
if(packet == NULL || len <= 0)
return -1;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return -2;
int pno = 0, total = len;
JANUS_LOG(LOG_HUGE, " Parsing compound packet (total of %d bytes)\n", total);
while(rtcp) {
pno++;
/* TODO Should we handle any of these packets ourselves, or just relay them? */
switch(rtcp->type) {
case RTCP_SR: {
/* SR, sender report */
JANUS_LOG(LOG_HUGE, " #%d SR (200)\n", pno);
janus_rtcp_sr *sr = (janus_rtcp_sr *)rtcp;
/* If an RTCP context was provided, update it with info on this SR */
janus_rtcp_incoming_sr(ctx, sr);
if(fixssrc && newssrcl) {
sr->ssrc = htonl(newssrcl);
}
if(fixssrc && newssrcr && sr->header.rc > 0) {
sr->rb[0].ssrc = htonl(newssrcr);
}
break;
}
case RTCP_RR: {
/* RR, receiver report */
JANUS_LOG(LOG_HUGE, " #%d RR (201)\n", pno);
janus_rtcp_rr *rr = (janus_rtcp_rr *)rtcp;
/* If an RTCP context was provided, update it with info on this RR */
janus_rtcp_incoming_rr(ctx, rr);
if(fixssrc && newssrcl) {
rr->ssrc = htonl(newssrcl);
}
if(fixssrc && newssrcr && rr->header.rc > 0) {
rr->rb[0].ssrc = htonl(newssrcr);
}
break;
}
case RTCP_SDES: {
/* SDES, source description */
JANUS_LOG(LOG_HUGE, " #%d SDES (202)\n", pno);
janus_rtcp_sdes *sdes = (janus_rtcp_sdes *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(sdes->chunk.ssrc));
if(fixssrc && newssrcl) {
sdes->chunk.ssrc = htonl(newssrcl);
}
break;
}
case RTCP_BYE: {
/* BYE, goodbye */
JANUS_LOG(LOG_HUGE, " #%d BYE (203)\n", pno);
janus_rtcp_bye *bye = (janus_rtcp_bye *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(bye->ssrc[0]));
if(fixssrc && newssrcl) {
bye->ssrc[0] = htonl(newssrcl);
}
break;
}
case RTCP_APP: {
/* APP, application-defined */
JANUS_LOG(LOG_HUGE, " #%d APP (204)\n", pno);
janus_rtcp_app *app = (janus_rtcp_app *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(app->ssrc));
if(fixssrc && newssrcl) {
app->ssrc = htonl(newssrcl);
}
break;
}
case RTCP_FIR: {
/* FIR, rfc2032 */
JANUS_LOG(LOG_HUGE, " #%d FIR (192)\n", pno);
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
if(fixssrc && newssrcr && (ntohs(rtcp->length) >= 20)) {
rtcpfb->media = htonl(newssrcr);
}
if(fixssrc && newssrcr) {
uint32_t *ssrc = (uint32_t *)rtcpfb->fci;
*ssrc = htonl(newssrcr);
}
break;
}
case RTCP_RTPFB: {
/* RTPFB, Transport layer FB message (rfc4585) */
//~ JANUS_LOG(LOG_HUGE, " #%d RTPFB (205)\n", pno);
gint fmt = rtcp->rc;
//~ JANUS_LOG(LOG_HUGE, " -- FMT: %u\n", fmt);
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(rtcpfb->ssrc));
if(fmt == 1) {
JANUS_LOG(LOG_HUGE, " #%d NACK -- RTPFB (205)\n", pno);
if(fixssrc && newssrcr) {
rtcpfb->media = htonl(newssrcr);
}
int nacks = ntohs(rtcp->length)-2; /* Skip SSRCs */
if(nacks > 0) {
JANUS_LOG(LOG_DBG, " Got %d nacks\n", nacks);
janus_rtcp_nack *nack = NULL;
uint16_t pid = 0;
uint16_t blp = 0;
int i=0, j=0;
char bitmask[20];
for(i=0; i< nacks; i++) {
nack = (janus_rtcp_nack *)rtcpfb->fci + i;
pid = ntohs(nack->pid);
blp = ntohs(nack->blp);
memset(bitmask, 0, 20);
for(j=0; j<16; j++) {
bitmask[j] = (blp & ( 1 << j )) >> j ? '1' : '0';
}
bitmask[16] = '\n';
JANUS_LOG(LOG_DBG, "[%d] %"SCNu16" / %s\n", i, pid, bitmask);
}
}
} else if(fmt == 3) { /* rfc5104 */
/* TMMBR: http://tools.ietf.org/html/rfc5104#section-4.2.1.1 */
JANUS_LOG(LOG_HUGE, " #%d TMMBR -- RTPFB (205)\n", pno);
if(fixssrc && newssrcr) {
uint32_t *ssrc = (uint32_t *)rtcpfb->fci;
*ssrc = htonl(newssrcr);
}
} else {
JANUS_LOG(LOG_HUGE, " #%d ??? -- RTPFB (205, fmt=%d)\n", pno, fmt);
}
if(fixssrc && newssrcl) {
rtcpfb->ssrc = htonl(newssrcl);
}
break;
}
case RTCP_PSFB: {
/* PSFB, Payload-specific FB message (rfc4585) */
//~ JANUS_LOG(LOG_HUGE, " #%d PSFB (206)\n", pno);
gint fmt = rtcp->rc;
//~ JANUS_LOG(LOG_HUGE, " -- FMT: %u\n", fmt);
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
//~ JANUS_LOG(LOG_HUGE, " -- SSRC: %u\n", ntohl(rtcpfb->ssrc));
if(fmt == 1) {
JANUS_LOG(LOG_HUGE, " #%d PLI -- PSFB (206)\n", pno);
if(fixssrc && newssrcr) {
rtcpfb->media = htonl(newssrcr);
}
} else if(fmt == 2) {
JANUS_LOG(LOG_HUGE, " #%d SLI -- PSFB (206)\n", pno);
} else if(fmt == 3) {
JANUS_LOG(LOG_HUGE, " #%d RPSI -- PSFB (206)\n", pno);
} else if(fmt == 4) { /* rfc5104 */
/* FIR: http://tools.ietf.org/html/rfc5104#section-4.3.1.1 */
JANUS_LOG(LOG_HUGE, " #%d FIR -- PSFB (206)\n", pno);
if(fixssrc && newssrcr) {
rtcpfb->media = htonl(newssrcr);
}
if(fixssrc && newssrcr) {
uint32_t *ssrc = (uint32_t *)rtcpfb->fci;
*ssrc = htonl(newssrcr);
}
} else if(fmt == 5) { /* rfc5104 */
/* FIR: http://tools.ietf.org/html/rfc5104#section-4.3.2.1 */
JANUS_LOG(LOG_HUGE, " #%d PLI -- TSTR (206)\n", pno);
if(fixssrc && newssrcr) {
uint32_t *ssrc = (uint32_t *)rtcpfb->fci;
*ssrc = htonl(newssrcr);
}
} else if(fmt == 15) {
//~ JANUS_LOG(LOG_HUGE, " -- This is a AFB!\n");
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
if(fixssrc && newssrcr) {
rtcpfb->ssrc = htonl(newssrcr);
rtcpfb->media = 0;
}
janus_rtcp_fb_remb *remb = (janus_rtcp_fb_remb *)rtcpfb->fci;
if(remb->id[0] == 'R' && remb->id[1] == 'E' && remb->id[2] == 'M' && remb->id[3] == 'B') {
JANUS_LOG(LOG_HUGE, " #%d REMB -- PSFB (206)\n", pno);
if(fixssrc && newssrcr) {
remb->ssrc[0] = htonl(newssrcr);
}
/* FIXME From rtcp_utility.cc */
unsigned char *_ptrRTCPData = (unsigned char *)remb;
_ptrRTCPData += 4; // Skip unique identifier and num ssrc
//~ JANUS_LOG(LOG_HUGE, " %02X %02X %02X %02X\n", _ptrRTCPData[0], _ptrRTCPData[1], _ptrRTCPData[2], _ptrRTCPData[3]);
uint8_t numssrc = (_ptrRTCPData[0]);
uint8_t brExp = (_ptrRTCPData[1] >> 2) & 0x3F;
uint32_t brMantissa = (_ptrRTCPData[1] & 0x03) << 16;
brMantissa += (_ptrRTCPData[2] << 8);
brMantissa += (_ptrRTCPData[3]);
uint32_t bitRate = brMantissa << brExp;
JANUS_LOG(LOG_HUGE, " -- -- -- REMB: %u * 2^%u = %"SCNu32" (%d SSRCs, %u)\n",
brMantissa, brExp, bitRate, numssrc, ntohl(remb->ssrc[0]));
} else {
JANUS_LOG(LOG_HUGE, " #%d AFB ?? -- PSFB (206)\n", pno);
}
} else {
JANUS_LOG(LOG_HUGE, " #%d ?? -- PSFB (206, fmt=%d)\n", pno, fmt);
}
if(fixssrc && newssrcl) {
rtcpfb->ssrc = htonl(newssrcl);
}
break;
}
case RTCP_XR: {
/* XR, extended reports (rfc3611) */
janus_rtcp_xr *xr = (janus_rtcp_xr *)rtcp;
if(fixssrc && newssrcl) {
xr->ssrc = htonl(newssrcl);
}
/* TODO Fix report blocks too, once we support them */
break;
}
default:
JANUS_LOG(LOG_ERR, " Unknown RTCP PT %d\n", rtcp->type);
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
JANUS_LOG(LOG_HUGE, " RTCP PT %d, length: %d bytes\n", rtcp->type, length*4+4);
if(length == 0) {
//~ JANUS_LOG(LOG_HUGE, " 0-length, end of compound packet\n");
break;
}
total -= length*4+4;
//~ JANUS_LOG(LOG_HUGE, " Packet has length %d (%d bytes, %d remaining), moving to next one...\n", length, length*4+4, total);
if(total <= 0) {
JANUS_LOG(LOG_HUGE, " End of compound packet\n");
break;
}
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return 0;
}
char *janus_rtcp_filter(char *packet, int len, int *newlen) {
if(packet == NULL || len <= 0 || newlen == NULL)
return NULL;
*newlen = 0;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return NULL;
char *filtered = NULL;
int total = len, length = 0, bytes = 0;
/* Iterate on the compound packets */
gboolean keep = TRUE;
while(rtcp) {
keep = TRUE;
length = ntohs(rtcp->length);
if(length == 0)
break;
bytes = length*4+4;
switch(rtcp->type) {
case RTCP_SR:
case RTCP_RR:
case RTCP_SDES:
/* These are packets we generate ourselves, so remove them */
keep = FALSE;
break;
case RTCP_BYE:
case RTCP_APP:
case RTCP_FIR:
case RTCP_PSFB:
break;
case RTCP_RTPFB:
if(rtcp->rc == 1) {
/* We handle NACKs ourselves as well, remove this too */
keep = FALSE;
break;
}
break;
case RTCP_XR:
/* FIXME We generate RR/SR ourselves, so remove XR */
keep = FALSE;
break;
default:
JANUS_LOG(LOG_ERR, "Unknown RTCP PT %d\n", rtcp->type);
/* FIXME Should we allow this to go through instead? */
keep = FALSE;
break;
}
if(keep) {
/* Keep this packet */
if(filtered == NULL)
filtered = g_malloc0(total);
memcpy(filtered+*newlen, (char *)rtcp, bytes);
*newlen += bytes;
}
total -= bytes;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return filtered;
}
int janus_rtcp_process_incoming_rtp(janus_rtcp_context *ctx, char *packet, int len) {
if(ctx == NULL || packet == NULL || len < 1)
return -1;
/* First of all, let's check if this is G.711: in case we may need to change the timestamp base */
janus_rtp_header *rtp = (janus_rtp_header *)packet;
int pt = rtp->type;
if((pt == 0 || pt == 8) && (ctx->tb == 48000))
ctx->tb = 8000;
/* Now parse this RTP packet header and update the rtcp_context instance */
uint16_t seq_number = ntohs(rtp->seq_number);
if(ctx->base_seq == 0 && ctx->seq_cycle == 0)
ctx->base_seq = seq_number;
ctx->received++;
if((int16_t)(seq_number - ctx->max_seq_nr) < 0) {
/* Late packet or retransmission */
ctx->retransmitted++;
} else {
if(seq_number < ctx->max_seq_nr)
ctx->seq_cycle++;
ctx->max_seq_nr = seq_number;
}
uint32_t rtp_expected = 0x0;
if(ctx->seq_cycle > 0) {
rtp_expected = ctx->seq_cycle;
rtp_expected = rtp_expected << 16;
}
rtp_expected = rtp_expected + 1 + ctx->max_seq_nr - ctx->base_seq;
ctx->lost = rtp_expected - ctx->received;
ctx->expected = rtp_expected;
uint64_t arrival = (janus_get_monotonic_time() * ctx->tb) / 1000000;
uint64_t transit = arrival - ntohl(rtp->timestamp);
uint64_t d = abs(transit - ctx->transit);
ctx->transit = transit;
ctx->jitter += (1./16.) * ((double)d - ctx->jitter);
/* RTP packet received: it means we can start sending RR */
ctx->rtp_recvd = 1;
return 0;
}
uint32_t janus_rtcp_context_get_rtt(janus_rtcp_context *ctx) {
return ctx ? ctx->rtt : 0;
}
uint32_t janus_rtcp_context_get_in_link_quality(janus_rtcp_context *ctx) {
return ctx ? (uint32_t)(ctx->in_link_quality + 0.5) : 0;
}
uint32_t janus_rtcp_context_get_in_media_link_quality(janus_rtcp_context *ctx) {
return ctx ? (uint32_t)(ctx->in_media_link_quality + 0.5) : 0;
}
uint32_t janus_rtcp_context_get_out_link_quality(janus_rtcp_context *ctx) {
return ctx ? (uint32_t)(ctx->out_link_quality + 0.5) : 0;
}
uint32_t janus_rtcp_context_get_out_media_link_quality(janus_rtcp_context *ctx) {
return ctx ? (uint32_t)(ctx->out_media_link_quality + 0.5) : 0;
}
uint32_t janus_rtcp_context_get_lost_all(janus_rtcp_context *ctx, gboolean remote) {
if(ctx == NULL)
return 0;
return remote ? ctx->lost_remote : ctx->lost;
}
static uint32_t janus_rtcp_context_get_lost(janus_rtcp_context *ctx) {
if(ctx == NULL)
return 0;
uint32_t lost;
if(ctx->lost > 0x7FFFFF) {
lost = 0x7FFFFF;
} else {
lost = ctx->lost;
}
return lost;
}
static uint32_t janus_rtcp_context_get_lost_fraction(janus_rtcp_context *ctx) {
if(ctx == NULL)
return 0;
uint32_t expected_interval = ctx->expected - ctx->expected_prior;
uint32_t received_interval = ctx->received - ctx->received_prior;
int32_t lost_interval = expected_interval - received_interval;
uint32_t fraction;
if(expected_interval == 0 || lost_interval <=0)
fraction = 0;
else
fraction = (lost_interval << 8) / expected_interval;
return fraction << 24;
}
uint32_t janus_rtcp_context_get_jitter(janus_rtcp_context *ctx, gboolean remote) {
if(ctx == NULL || ctx->tb == 0)
return 0;
return (uint32_t) floor((remote ? ctx->jitter_remote : ctx->jitter) * 1000.0 / ctx->tb);
}
static void janus_rtcp_estimate_in_link_quality(janus_rtcp_context *ctx) {
int64_t ts = janus_get_monotonic_time();
int64_t delta_t = ts - ctx->out_rr_last_ts;
if(delta_t < 3*G_USEC_PER_SEC) {
return;
}
ctx->out_rr_last_ts = ts;
uint32_t expected_interval = ctx->expected - ctx->expected_prior;
uint32_t received_interval = ctx->received - ctx->received_prior;
uint32_t retransmitted_interval = ctx->retransmitted - ctx->retransmitted_prior;
int32_t link_lost = expected_interval - (received_interval - retransmitted_interval);
double link_q = !expected_interval ? 0 : 100.0 - (100.0 * (double)link_lost / (double)expected_interval);
ctx->in_link_quality = janus_rtcp_link_quality_filter(ctx->in_link_quality, link_q);
int32_t lost = expected_interval - received_interval;
if (lost < 0) {
lost = 0;
}
double media_link_q = !expected_interval ? 0 : 100.0 - (100.0 * (double)lost / (double)expected_interval);
ctx->in_media_link_quality = janus_rtcp_link_quality_filter(ctx->in_media_link_quality, media_link_q);
JANUS_LOG(LOG_HUGE, "In link quality=%"SCNu32", media link quality=%"SCNu32"\n", janus_rtcp_context_get_in_link_quality(ctx), janus_rtcp_context_get_in_media_link_quality(ctx));
}
int janus_rtcp_report_block(janus_rtcp_context *ctx, janus_report_block *rb) {
if(ctx == NULL || rb == NULL)
return -1;
gint64 now = janus_get_monotonic_time();
rb->jitter = htonl((uint32_t) ctx->jitter);
rb->ehsnr = htonl((((uint32_t) 0x0 + ctx->seq_cycle) << 16) + ctx->max_seq_nr);
uint32_t lost = janus_rtcp_context_get_lost(ctx);
uint32_t fraction = janus_rtcp_context_get_lost_fraction(ctx);
janus_rtcp_estimate_in_link_quality(ctx);
ctx->expected_prior = ctx->expected;
ctx->received_prior = ctx->received;
ctx->retransmitted_prior = ctx->retransmitted;
rb->flcnpl = htonl(lost | fraction);
if(ctx->lsr > 0) {
rb->lsr = htonl(ctx->lsr);
rb->delay = htonl(((now - ctx->lsr_ts) << 16) / 1000000);
} else {
rb->lsr = 0;
rb->delay = 0;
}
ctx->last_sent = now;
return 0;
}
gboolean janus_rtcp_parse_lost_info(char *packet, int len, uint32_t *lost, int *fraction) {
/* Parse RTCP compound packet */
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return FALSE;
int pno = 0, total = len;
while(rtcp) {
pno++;
switch(rtcp->type) {
case RTCP_RR: {
janus_rtcp_rr *rr = (janus_rtcp_rr *)rtcp;
if(rr->header.rc > 0) {
if(fraction)
*fraction = ntohl(rr->rb[0].flcnpl) >> 24;
if(lost)
*lost = ntohl(rr->rb[0].flcnpl) & 0x00FFFFFF;
return TRUE;
}
return FALSE;
}
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0)
break;
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return FALSE;
}
gboolean janus_rtcp_has_bye(char *packet, int len) {
/* Parse RTCP compound packet */
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return FALSE;
int pno = 0, total = len;
while(rtcp) {
pno++;
switch(rtcp->type) {
case RTCP_BYE:
return TRUE;
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0)
break;
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return FALSE;
}
gboolean janus_rtcp_has_fir(char *packet, int len) {
/* Parse RTCP compound packet */
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return FALSE;
int pno = 0, total = len;
while(rtcp) {
pno++;
switch(rtcp->type) {
case RTCP_FIR:
return TRUE;
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0)
break;
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return FALSE;
}
gboolean janus_rtcp_has_pli(char *packet, int len) {
/* Parse RTCP compound packet */
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return FALSE;
int pno = 0, total = len;
while(rtcp) {
pno++;
switch(rtcp->type) {
case RTCP_PSFB: {
gint fmt = rtcp->rc;
if(fmt == 1)
return TRUE;
break;
}
default:
break;
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0)
break;
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return FALSE;
}
GSList *janus_rtcp_get_nacks(char *packet, int len) {
if(packet == NULL || len == 0)
return NULL;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return NULL;
/* FIXME Get list of sequence numbers we should send again */
GSList *list = NULL;
int total = len;
while(rtcp) {
if(rtcp->type == RTCP_RTPFB) {
gint fmt = rtcp->rc;
if(fmt == 1) {
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
int nacks = ntohs(rtcp->length)-2; /* Skip SSRCs */
if(nacks > 0) {
JANUS_LOG(LOG_DBG, " Got %d nacks\n", nacks);
janus_rtcp_nack *nack = NULL;
uint16_t pid = 0;
uint16_t blp = 0;
int i=0, j=0;
char bitmask[20];
for(i=0; i< nacks; i++) {
nack = (janus_rtcp_nack *)rtcpfb->fci + i;
pid = ntohs(nack->pid);
list = g_slist_append(list, GUINT_TO_POINTER(pid));
blp = ntohs(nack->blp);
memset(bitmask, 0, 20);
for(j=0; j<16; j++) {
bitmask[j] = (blp & ( 1 << j )) >> j ? '1' : '0';
if((blp & ( 1 << j )) >> j)
list = g_slist_append(list, GUINT_TO_POINTER(pid+j+1));
}
bitmask[16] = '\n';
JANUS_LOG(LOG_DBG, "[%d] %"SCNu16" / %s\n", i, pid, bitmask);
}
}
break;
}
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0)
break;
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return list;
}
int janus_rtcp_remove_nacks(char *packet, int len) {
if(packet == NULL || len == 0)
return len;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return len;
/* Find the NACK message */
char *nacks = NULL;
int total = len, nacks_len = 0;
while(rtcp) {
if(rtcp->type == RTCP_RTPFB) {
gint fmt = rtcp->rc;
if(fmt == 1) {
nacks = (char *)rtcp;
}
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0)
break;
if(nacks != NULL) {
nacks_len = length*4+4;
break;
}
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
if(nacks != NULL) {
total = len - ((nacks-packet)+nacks_len);
if(total < 0) {
/* FIXME Should never happen, but you never know: do nothing */
return len;
} else if(total == 0) {
/* NACK was the last compound packet, easy enough */
return len-nacks_len;
} else {
/* NACK is between two compound packets, move them around */
int i=0;
for(i=0; i<total; i++)
*(nacks+i) = *(nacks+nacks_len+i);
return len-nacks_len;
}
}
return len;
}
/* Query an existing REMB message */
uint32_t janus_rtcp_get_remb(char *packet, int len) {
if(packet == NULL || len == 0)
return 0;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return 0;
/* Get REMB bitrate, if any */
int total = len;
while(rtcp) {
if(rtcp->type == RTCP_PSFB) {
gint fmt = rtcp->rc;
if(fmt == 15) {
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
janus_rtcp_fb_remb *remb = (janus_rtcp_fb_remb *)rtcpfb->fci;
if(remb->id[0] == 'R' && remb->id[1] == 'E' && remb->id[2] == 'M' && remb->id[3] == 'B') {
/* FIXME From rtcp_utility.cc */
unsigned char *_ptrRTCPData = (unsigned char *)remb;
_ptrRTCPData += 4; /* Skip unique identifier and num ssrc */
//~ JANUS_LOG(LOG_VERB, " %02X %02X %02X %02X\n", _ptrRTCPData[0], _ptrRTCPData[1], _ptrRTCPData[2], _ptrRTCPData[3]);
uint8_t brExp = (_ptrRTCPData[1] >> 2) & 0x3F;
uint32_t brMantissa = (_ptrRTCPData[1] & 0x03) << 16;
brMantissa += (_ptrRTCPData[2] << 8);
brMantissa += (_ptrRTCPData[3]);
uint32_t bitrate = brMantissa << brExp;
JANUS_LOG(LOG_HUGE, "Got REMB bitrate %"SCNu32"\n", bitrate);
return bitrate;
}
}
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0)
break;
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return 0;
}
/* Change an existing REMB message */
int janus_rtcp_cap_remb(char *packet, int len, uint32_t bitrate) {
if(packet == NULL || len == 0)
return -1;
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
if(rtcp->version != 2)
return -2;
if(bitrate == 0)
return 0; /* No need to cap */
/* Cap REMB bitrate */
int total = len;
while(rtcp) {
if(rtcp->type == RTCP_PSFB) {
gint fmt = rtcp->rc;
if(fmt == 15) {
janus_rtcp_fb *rtcpfb = (janus_rtcp_fb *)rtcp;
janus_rtcp_fb_remb *remb = (janus_rtcp_fb_remb *)rtcpfb->fci;
if(remb->id[0] == 'R' && remb->id[1] == 'E' && remb->id[2] == 'M' && remb->id[3] == 'B') {
/* FIXME From rtcp_utility.cc */
unsigned char *_ptrRTCPData = (unsigned char *)remb;
_ptrRTCPData += 4; /* Skip unique identifier and num ssrc */
//~ JANUS_LOG(LOG_VERB, " %02X %02X %02X %02X\n", _ptrRTCPData[0], _ptrRTCPData[1], _ptrRTCPData[2], _ptrRTCPData[3]);
uint8_t brExp = (_ptrRTCPData[1] >> 2) & 0x3F;
uint32_t brMantissa = (_ptrRTCPData[1] & 0x03) << 16;
brMantissa += (_ptrRTCPData[2] << 8);
brMantissa += (_ptrRTCPData[3]);
uint32_t origbitrate = brMantissa << brExp;
if(origbitrate > bitrate) {
JANUS_LOG(LOG_HUGE, "Got REMB bitrate %"SCNu32", need to cap it to %"SCNu32"\n", origbitrate, bitrate);
JANUS_LOG(LOG_HUGE, " >> %u * 2^%u = %"SCNu32"\n", brMantissa, brExp, origbitrate);
/* bitrate --> brexp/brmantissa */
uint8_t b = 0;
uint8_t newbrexp = 0;
uint32_t newbrmantissa = 0;
for(b=0; b<32; b++) {
if(bitrate <= ((uint32_t) 0x3FFFF << b)) {
newbrexp = b;
break;
}
}
if(b > 31)
b = 31;
newbrmantissa = bitrate >> b;
JANUS_LOG(LOG_HUGE, "new brexp: %"SCNu8"\n", newbrexp);
JANUS_LOG(LOG_HUGE, "new brmantissa: %"SCNu32"\n", newbrmantissa);
/* FIXME From rtcp_sender.cc */
_ptrRTCPData[1] = (uint8_t)((newbrexp << 2) + ((newbrmantissa >> 16) & 0x03));
_ptrRTCPData[2] = (uint8_t)(newbrmantissa >> 8);
_ptrRTCPData[3] = (uint8_t)(newbrmantissa);
}
}
}
}
/* Is this a compound packet? */
int length = ntohs(rtcp->length);
if(length == 0)
break;
total -= length*4+4;
if(total <= 0)
break;
rtcp = (janus_rtcp_header *)((uint32_t*)rtcp + length + 1);
}
return 0;
}
/* Generate a new SDES message */
int janus_rtcp_sdes_cname(char *packet, int len, const char *cname, int cnamelen) {
if(packet == NULL || len <= 0 || cname == NULL || cnamelen <= 0)
return -1;
memset(packet, 0, len);
janus_rtcp_header *rtcp = (janus_rtcp_header *)packet;
/* Set header */
rtcp->version = 2;
rtcp->type = RTCP_SDES;
rtcp->rc = 1;
int plen = 8; /* Header + chunk + item header */
plen += cnamelen+3; /* cname item header(2) + cnamelen + terminator(1) */
/* calculate padding length. assume that plen is shorter than 65535 */
plen = (plen + 3) & 0xFFFC;
if(len < plen) {
JANUS_LOG(LOG_ERR, "Buffer too small for SDES message: %d < %d\n", len, plen);
return -1;
}