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RTC: Merge srs_rtp_seq_distance with srs_seq_is_newer

This commit is contained in:
忘篱 2020-05-17 09:03:40 +08:00
parent 3f5ab8dc63
commit d603b1580e
5 changed files with 76 additions and 85 deletions

View file

@ -34,17 +34,6 @@ class SrsRtpPacket2;
class SrsRtpQueue; class SrsRtpQueue;
class SrsRtpRingBuffer; class SrsRtpRingBuffer;
// The "distance" between two uint16 number, for example:
// distance(prev_value=3, value=5) === (int16_t)(uint16_t)((uint16_t)3-(uint16_t)5) === -2
// distance(prev_value=3, value=65534) === (int16_t)(uint16_t)((uint16_t)3-(uint16_t)65534) === 5
// distance(prev_value=65532, value=65534) === (int16_t)(uint16_t)((uint16_t)65532-(uint16_t)65534) === -2
// For RTP sequence, it's only uint16 and may flip back, so 3 maybe 3+0xffff.
// @see https://mp.weixin.qq.com/s/JZTInmlB9FUWXBQw_7NYqg
inline int16_t srs_rtp_seq_distance(const uint16_t& prev_value, const uint16_t& value)
{
return (int16_t)(value - prev_value);
}
// For UDP, the packets sequence may present as bellow: // For UDP, the packets sequence may present as bellow:
// [seq1(done)|seq2|seq3 ... seq10|seq11(lost)|seq12|seq13] // [seq1(done)|seq2|seq3 ... seq10|seq11(lost)|seq12|seq13]
// \___(head_sequence_) \ \___(highest_sequence_) // \___(head_sequence_) \ \___(highest_sequence_)

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@ -61,7 +61,7 @@ struct SrsRtcpHeader
struct SrsSeqCompareLess { struct SrsSeqCompareLess {
bool operator()(const uint16_t &lhs, const uint16_t &rhs) const { bool operator()(const uint16_t &lhs, const uint16_t &rhs) const {
return SrsSeqIsNewer(rhs, lhs); return srs_seq_is_newer(rhs, lhs);
} }
}; };

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@ -33,54 +33,24 @@ using namespace std;
#include <srs_kernel_utility.hpp> #include <srs_kernel_utility.hpp>
#include <srs_kernel_flv.hpp> #include <srs_kernel_flv.hpp>
//sn comparisonif current_sn is more(newer) than last_snreturn trueelse return false // If value is newer than pre_valuereturn true; otherwise false
bool SrsSeqIsNewer(uint16_t current_sn, uint16_t last_sn) { bool srs_seq_is_newer(uint16_t value, uint16_t pre_value) {
if(current_sn > last_sn) { return srs_rtp_seq_distance(pre_value, value) > 0;
//current_sn 65533 last_sn 5
if(current_sn - last_sn > 0x8000) {
return false;
} else {
return true;
}
} else {
//current_sn 2 last_sn 65535
if(current_sn - last_sn < -0x8000) {
return true;
} else {
return false;
}
}
} }
bool SrsSeqIsRoolback(uint16_t current_sn, uint16_t last_sn) bool srs_seq_is_roolback(uint16_t value, uint16_t pre_value)
{ {
if(SrsSeqIsNewer(current_sn, last_sn)) { if(srs_seq_is_newer(value, pre_value)) {
if((last_sn > current_sn)) { if((pre_value > value)) {
return true; return true;
} }
} }
return false; return false;
} }
// caculate the difference between sn. If current_sn is more then last_sn, return positive difference, else return negative difference. // If value is newer then pre_value, return positive, otherwise negative.
int32_t SrsSeqDistance(uint16_t current_sn, uint16_t last_sn) { int32_t srs_seq_distance(uint16_t value, uint16_t pre_value) {
if(current_sn > last_sn) { return srs_rtp_seq_distance(pre_value, value);
//current_sn 65535 last_sn 0
if(current_sn - last_sn > 0x8000) {
return (current_sn - last_sn - 1 - 65535);
} else {
return (current_sn - last_sn);
}
} else {
//current_sn 0 last_sn 65535
if(current_sn - last_sn < -0x8000) {
return (current_sn - last_sn + 65535 + 1);
} else {
return (current_sn - last_sn);
// current_sn 15039 last_sn 15042
//return last_sn - current_sn;
}
}
} }
SrsRtpHeader::SrsRtpHeader() SrsRtpHeader::SrsRtpHeader()

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@ -58,11 +58,22 @@ class SrsRtpRawPayload;
class SrsRtpFUAPayload2; class SrsRtpFUAPayload2;
class SrsSharedPtrMessage; class SrsSharedPtrMessage;
// TODO: FIXME: Merge with srs_rtp_seq_distance // The "distance" between two uint16 number, for example:
// @see https://mp.weixin.qq.com/s/JZTInmlB9FUWXBQw_7NYqg // distance(prev_value=3, value=5) === (int16_t)(uint16_t)((uint16_t)3-(uint16_t)5) === -2
bool SrsSeqIsNewer(uint16_t current_sn, uint16_t last_sn); // distance(prev_value=3, value=65534) === (int16_t)(uint16_t)((uint16_t)3-(uint16_t)65534) === 5
bool SrsSeqIsRoolback(uint16_t current_sn, uint16_t last_sn); // distance(prev_value=65532, value=65534) === (int16_t)(uint16_t)((uint16_t)65532-(uint16_t)65534) === -2
int32_t SrsSeqDistance(uint16_t current_sn, uint16_t last_sn); // For RTP sequence, it's only uint16 and may flip back, so 3 maybe 3+0xffff.
// @remark Note that srs_rtp_seq_distance(0, 32768)>0 is TRUE by https://mp.weixin.qq.com/s/JZTInmlB9FUWXBQw_7NYqg
// but for WebRTC jitter buffer it's FALSE and we follow it.
// @remark For srs_rtp_seq_distance(32768, 0)>0, it's FALSE definitely.
inline int16_t srs_rtp_seq_distance(const uint16_t& prev_value, const uint16_t& value)
{
return (int16_t)(value - prev_value);
}
bool srs_seq_is_newer(uint16_t value, uint16_t pre_value);
bool srs_seq_is_roolback(uint16_t value, uint16_t pre_value);
int32_t srs_seq_distance(uint16_t value, uint16_t pre_value);
class SrsRtpHeader class SrsRtpHeader
{ {

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@ -55,50 +55,71 @@ VOID TEST(KernelRTCTest, SequenceCompare)
EXPECT_FALSE(srs_rtp_seq_distance(255, 65535) > 0); EXPECT_FALSE(srs_rtp_seq_distance(255, 65535) > 0);
EXPECT_FALSE(srs_rtp_seq_distance(255, 65280) > 0); EXPECT_FALSE(srs_rtp_seq_distance(255, 65280) > 0);
// Note that it's TRUE at https://mp.weixin.qq.com/s/JZTInmlB9FUWXBQw_7NYqg // Note that srs_rtp_seq_distance(0, 32768)>0 is TRUE by https://mp.weixin.qq.com/s/JZTInmlB9FUWXBQw_7NYqg
// but for WebRTC jitter buffer it's FALSE and we follow it.
EXPECT_FALSE(srs_rtp_seq_distance(0, 32768) > 0); EXPECT_FALSE(srs_rtp_seq_distance(0, 32768) > 0);
// It's FALSE definitely. // It's FALSE definitely.
EXPECT_FALSE(srs_rtp_seq_distance(32768, 0) > 0); EXPECT_FALSE(srs_rtp_seq_distance(32768, 0) > 0);
} }
if (true) { if (true) {
EXPECT_FALSE(SrsSeqIsNewer(1, 1)); EXPECT_FALSE(srs_seq_is_newer(1, 1));
EXPECT_TRUE(SrsSeqIsNewer(65535, 65534)); EXPECT_TRUE(srs_seq_is_newer(65535, 65534));
EXPECT_TRUE(SrsSeqIsNewer(1, 0)); EXPECT_TRUE(srs_seq_is_newer(1, 0));
EXPECT_TRUE(SrsSeqIsNewer(256, 255)); EXPECT_TRUE(srs_seq_is_newer(256, 255));
EXPECT_TRUE(SrsSeqIsNewer(0, 65535)); EXPECT_TRUE(srs_seq_is_newer(0, 65535));
EXPECT_TRUE(SrsSeqIsNewer(0, 65280)); EXPECT_TRUE(srs_seq_is_newer(0, 65280));
EXPECT_TRUE(SrsSeqIsNewer(255, 65535)); EXPECT_TRUE(srs_seq_is_newer(255, 65535));
EXPECT_TRUE(SrsSeqIsNewer(255, 65280)); EXPECT_TRUE(srs_seq_is_newer(255, 65280));
EXPECT_FALSE(SrsSeqIsNewer(65535, 0)); EXPECT_FALSE(srs_seq_is_newer(65535, 0));
EXPECT_FALSE(SrsSeqIsNewer(65280, 0)); EXPECT_FALSE(srs_seq_is_newer(65280, 0));
EXPECT_FALSE(SrsSeqIsNewer(65535, 255)); EXPECT_FALSE(srs_seq_is_newer(65535, 255));
EXPECT_FALSE(SrsSeqIsNewer(65280, 255)); EXPECT_FALSE(srs_seq_is_newer(65280, 255));
EXPECT_TRUE(SrsSeqIsNewer(32768, 0)); EXPECT_FALSE(srs_seq_is_newer(32768, 0));
EXPECT_FALSE(SrsSeqIsNewer(0, 32768)); EXPECT_FALSE(srs_seq_is_newer(0, 32768));
} }
if (true) { if (true) {
EXPECT_FALSE(SrsSeqDistance(1, 1) > 0); EXPECT_FALSE(srs_seq_distance(1, 1) > 0);
EXPECT_TRUE(SrsSeqDistance(65535, 65534) > 0); EXPECT_TRUE(srs_seq_distance(65535, 65534) > 0);
EXPECT_TRUE(SrsSeqDistance(1, 0) > 0); EXPECT_TRUE(srs_seq_distance(1, 0) > 0);
EXPECT_TRUE(SrsSeqDistance(256, 255) > 0); EXPECT_TRUE(srs_seq_distance(256, 255) > 0);
EXPECT_TRUE(SrsSeqDistance(0, 65535) > 0); EXPECT_TRUE(srs_seq_distance(0, 65535) > 0);
EXPECT_TRUE(SrsSeqDistance(0, 65280) > 0); EXPECT_TRUE(srs_seq_distance(0, 65280) > 0);
EXPECT_TRUE(SrsSeqDistance(255, 65535) > 0); EXPECT_TRUE(srs_seq_distance(255, 65535) > 0);
EXPECT_TRUE(SrsSeqDistance(255, 65280) > 0); EXPECT_TRUE(srs_seq_distance(255, 65280) > 0);
EXPECT_FALSE(SrsSeqDistance(65535, 0) > 0); EXPECT_FALSE(srs_seq_distance(65535, 0) > 0);
EXPECT_FALSE(SrsSeqDistance(65280, 0) > 0); EXPECT_FALSE(srs_seq_distance(65280, 0) > 0);
EXPECT_FALSE(SrsSeqDistance(65535, 255) > 0); EXPECT_FALSE(srs_seq_distance(65535, 255) > 0);
EXPECT_FALSE(SrsSeqDistance(65280, 255) > 0); EXPECT_FALSE(srs_seq_distance(65280, 255) > 0);
EXPECT_TRUE(SrsSeqDistance(32768, 0) > 0); EXPECT_FALSE(srs_seq_distance(32768, 0) > 0);
EXPECT_FALSE(SrsSeqDistance(0, 32768) > 0); EXPECT_FALSE(srs_seq_distance(0, 32768) > 0);
}
if (true) {
EXPECT_FALSE(srs_seq_is_roolback(1, 1));
EXPECT_FALSE(srs_seq_is_roolback(65535, 65534));
EXPECT_FALSE(srs_seq_is_roolback(1, 0));
EXPECT_FALSE(srs_seq_is_roolback(256, 255));
EXPECT_TRUE(srs_seq_is_roolback(0, 65535));
EXPECT_TRUE(srs_seq_is_roolback(0, 65280));
EXPECT_TRUE(srs_seq_is_roolback(255, 65535));
EXPECT_TRUE(srs_seq_is_roolback(255, 65280));
EXPECT_FALSE(srs_seq_is_roolback(65535, 0));
EXPECT_FALSE(srs_seq_is_roolback(65280, 0));
EXPECT_FALSE(srs_seq_is_roolback(65535, 255));
EXPECT_FALSE(srs_seq_is_roolback(65280, 255));
EXPECT_FALSE(srs_seq_is_roolback(32768, 0));
EXPECT_FALSE(srs_seq_is_roolback(0, 32768));
} }
} }