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RTC: Parse TWCC SN fastly.

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This commit is contained in:
winlin 2021-02-07 15:48:46 +08:00
parent 79a6907a65
commit 719df6fa41
3 changed files with 65 additions and 8 deletions
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62
trunk/src/kernel/srs_kernel_rtc_rtp.cpp
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@ -70,6 +70,68 @@ uint8_t srs_rtp_fast_parse_pt(char* buf, int size)
}
return buf[1] & 0x7f;
}
srs_error_t srs_rtp_fast_parse_twcc(char* buf, int size, SrsRtpExtensionTypes* ext_types, uint16_t& twcc_sn)
{
srs_error_t err = srs_success;
int need_size = 12 /*rtp head fix len*/ + 4 /* extension header len*/ + 3 /* twcc extension len*/;
if(size < (need_size)) {
return srs_error_new(ERROR_RTC_RTP_MUXER, "required %d bytes, actual %d", need_size, size);
}
uint8_t first = buf[0];
bool extension = (first & 0x10);
uint8_t cc = (first & 0x0F);
if(!extension) {
return srs_error_new(ERROR_RTC_RTP, "no extension in rtp");
}
need_size += cc * 4; // csrc size
if(size < (need_size)) {
return srs_error_new(ERROR_RTC_RTP_MUXER, "required %d bytes, actual %d", need_size, size);
}
buf += 12 + 4*cc;
uint16_t value = *((uint16_t*)buf);
value = ntohs(value);
if(0xBEDE != value) {
return srs_error_new(ERROR_RTC_RTP_MUXER, "no support this type(0x%02x) extension", value);
}
buf += 2;
uint16_t extension_length = ntohs(*((uint16_t*)buf));
buf += 2;
extension_length *= 4;
need_size += extension_length; // entension size
if(size < (need_size)) {
return srs_error_new(ERROR_RTC_RTP_MUXER, "required %d bytes, actual %d", need_size, size);
}
while(extension_length > 0) {
uint8_t v = buf[0];
buf++;
extension_length--;
if(0 == v) {
continue;
}
uint8_t id = (v & 0xF0) >>4;
uint8_t len = (v & 0x0F) + 1;
SrsRtpExtensionType xtype = ext_types->get_type(id);
if(xtype == kRtpExtensionTransportSequenceNumber) {
twcc_sn = ntohs(*((uint16_t*)buf));
return err;
} else {
buf += len;
extension_length -= len;
}
}
return err;
}
// If value is newer than pre_value，return true; otherwise false
bool srs_seq_is_newer(uint16_t value, uint16_t pre_value)