Rework sequencing code and fix audio dropout across 64K boundary in the process

src/Limelight-internal.h

@@ -21,7 +21,18 @@ extern AUDIO_RENDERER_CALLBACKS AudioCallbacks;
 extern int NegotiatedVideoFormat;
 extern volatile int ConnectionInterrupted;
 
-int isBeforeSignedInt(int numA, int numB, int ambiguousCase);
+#ifndef UINT24_MAX
+#define UINT24_MAX 0xFFFFFF
+#endif
+
+#define U16(x) ((unsigned short) ((x) & UINT16_MAX))
+#define U24(x) ((unsigned int) ((x) & UINT24_MAX))
+#define U32(x) ((unsigned int) ((x) & UINT32_MAX))
+
+#define isBefore16(x, y) (U16((x) - (y)) > (UINT16_MAX/2))
+#define isBefore24(x, y) (U24((x) - (y)) > (UINT24_MAX/2))
+#define isBefore32(x, y) (U32((x) - (y)) > (UINT32_MAX/2))
+
 int serviceEnetHost(ENetHost* client, ENetEvent* event, enet_uint32 timeoutMs);
 int extractVersionQuadFromString(const char* string, int* quad);
 int isReferenceFrameInvalidationEnabled(void);

src/Misc.c

@@ -31,23 +31,6 @@ int serviceEnetHost(ENetHost* client, ENetEvent* event, enet_uint32 timeoutMs) {
     return ret;
 }
 
-int isBeforeSignedInt(int numA, int numB, int ambiguousCase) {
-    // This should be the common case for most callers
-    if (numA == numB) {
-        return 0;
-    }
-
-    // If numA and numB have the same signs,
-    // we can just do a regular comparison.
-    if ((numA < 0 && numB < 0) || (numA >= 0 && numB >= 0)) {
-        return numA < numB;
-    }
-    else {
-        // The sign switch is ambiguous
-        return ambiguousCase;
-    }
-}
-
 int extractVersionQuadFromString(const char* string, int* quad) {
     char versionString[128];
     char* nextDot;

src/RtpFecQueue.c

@@ -2,9 +2,6 @@
 #include "RtpFecQueue.h"
 #include "rs.h"
 
-#define ushort(x) ((unsigned short) ((x) % (UINT16_MAX+1)))
-#define isBefore(x, y) (ushort((x) - (y)) > (UINT16_MAX/2))
-
 void RtpfInitializeQueue(PRTP_FEC_QUEUE queue) {
     reed_solomon_init();
     memset(queue, 0, sizeof(*queue));
@@ -31,7 +28,7 @@ void RtpfCleanupQueue(PRTP_FEC_QUEUE queue) {
 static int queuePacket(PRTP_FEC_QUEUE queue, PRTPFEC_QUEUE_ENTRY newEntry, int head, PRTP_PACKET packet, int length, int isParity) {
     PRTPFEC_QUEUE_ENTRY entry;
     
-    LC_ASSERT(!isBefore(packet->sequenceNumber, queue->nextRtpSequenceNumber));
+    LC_ASSERT(!isBefore16(packet->sequenceNumber, queue->nextRtpSequenceNumber));
 
     // Don't queue duplicates either
     entry = queue->bufferHead;
@@ -77,7 +74,7 @@ static int queuePacket(PRTP_FEC_QUEUE queue, PRTPFEC_QUEUE_ENTRY newEntry, int h
 
 // Returns 0 if the frame is completely constructed
 static int reconstructFrame(PRTP_FEC_QUEUE queue) {
-    int totalPackets = ushort(queue->bufferHighestSequenceNumber - queue->bufferLowestSequenceNumber) + 1;
+    int totalPackets = U16(queue->bufferHighestSequenceNumber - queue->bufferLowestSequenceNumber) + 1;
     int totalParityPackets = (queue->bufferDataPackets * queue->fecPercentage + 99) / 100;
     int parityPackets = totalPackets - queue->bufferDataPackets;
     int missingPackets = totalPackets - queue->bufferSize;
@@ -120,7 +117,7 @@ static int reconstructFrame(PRTP_FEC_QUEUE queue) {
 
     PRTPFEC_QUEUE_ENTRY entry = queue->bufferHead;
     while (entry != NULL) {
-        int index = ushort(entry->packet->sequenceNumber - queue->bufferLowestSequenceNumber);
+        int index = U16(entry->packet->sequenceNumber - queue->bufferLowestSequenceNumber);
         packets[index] = (unsigned char*) entry->packet;
         marks[index] = 0;
         
@@ -156,7 +153,7 @@ cleanup_packets:
             if (ret == 0 && i < queue->bufferDataPackets) {
                 PRTPFEC_QUEUE_ENTRY queueEntry = (PRTPFEC_QUEUE_ENTRY)&packets[i][receiveSize];
                 PRTP_PACKET rtpPacket = (PRTP_PACKET) packets[i];
-                rtpPacket->sequenceNumber = ushort(i + queue->bufferLowestSequenceNumber);
+                rtpPacket->sequenceNumber = U16(i + queue->bufferLowestSequenceNumber);
                 rtpPacket->header = queue->bufferHead->packet->header;
                 
                 int dataOffset = sizeof(*rtpPacket);
@@ -172,7 +169,7 @@ cleanup_packets:
                 // discarded by decoders. It's not safe to strip all zero padding because
                 // it may be a legitimate part of the H.264 bytestream.
 
-                LC_ASSERT(isBefore(rtpPacket->sequenceNumber, queue->bufferFirstParitySequenceNumber));                
+                LC_ASSERT(isBefore16(rtpPacket->sequenceNumber, queue->bufferFirstParitySequenceNumber));
                 queuePacket(queue, queueEntry, 0, rtpPacket, StreamConfig.packetSize + dataOffset, 0);
             } else if (packets[i] != NULL) {
                 free(packets[i]);
@@ -215,7 +212,7 @@ static void removeEntry(PRTP_FEC_QUEUE queue, PRTPFEC_QUEUE_ENTRY entry) {
 }
 
 int RtpfAddPacket(PRTP_FEC_QUEUE queue, PRTP_PACKET packet, int length, PRTPFEC_QUEUE_ENTRY packetEntry) {
-    if (isBefore(packet->sequenceNumber, queue->nextRtpSequenceNumber)) {
+    if (isBefore16(packet->sequenceNumber, queue->nextRtpSequenceNumber)) {
         // Reject packets behind our current sequence number
         return RTPF_RET_REJECTED;
     }
@@ -227,7 +224,7 @@ int RtpfAddPacket(PRTP_FEC_QUEUE queue, PRTP_PACKET packet, int length, PRTPFEC_
 
     PNV_VIDEO_PACKET nvPacket = (PNV_VIDEO_PACKET)(((char*)packet) + dataOffset);
     
-    if (isBefore(nvPacket->frameIndex, queue->currentFrameNumber)) {
+    if (isBefore16(nvPacket->frameIndex, queue->currentFrameNumber)) {
         // Reject frames behind our current frame number
         return RTPF_RET_REJECTED;
     }
@@ -257,21 +254,21 @@ int RtpfAddPacket(PRTP_FEC_QUEUE queue, PRTP_PACKET packet, int length, PRTPFEC_
         queue->bufferSize = 0;
         
         int fecIndex = (nvPacket->fecInfo & 0xFF000) >> 12;
-        queue->bufferLowestSequenceNumber = ushort(packet->sequenceNumber - fecIndex);
+        queue->bufferLowestSequenceNumber = U16(packet->sequenceNumber - fecIndex);
         queue->receivedBufferDataPackets = 0;
         queue->bufferHighestSequenceNumber = packet->sequenceNumber;
         queue->bufferDataPackets = ((nvPacket->fecInfo & 0xFFF00000) >> 20) / 4;
         queue->fecPercentage = ((nvPacket->fecInfo & 0xFF0) >> 4);
-        queue->bufferFirstParitySequenceNumber = ushort(queue->bufferLowestSequenceNumber + queue->bufferDataPackets);
+        queue->bufferFirstParitySequenceNumber = U16(queue->bufferLowestSequenceNumber + queue->bufferDataPackets);
-    } else if (isBefore(queue->bufferHighestSequenceNumber, packet->sequenceNumber)) {
+    } else if (isBefore16(queue->bufferHighestSequenceNumber, packet->sequenceNumber)) {
         queue->bufferHighestSequenceNumber = packet->sequenceNumber;
     }
     
-    if (!queuePacket(queue, packetEntry, 0, packet, length, !isBefore(packet->sequenceNumber, queue->bufferFirstParitySequenceNumber))) {
+    if (!queuePacket(queue, packetEntry, 0, packet, length, !isBefore16(packet->sequenceNumber, queue->bufferFirstParitySequenceNumber))) {
         return RTPF_RET_REJECTED;
     }
     else {
-        if (isBefore(packet->sequenceNumber, queue->bufferFirstParitySequenceNumber)) {
+        if (isBefore16(packet->sequenceNumber, queue->bufferFirstParitySequenceNumber)) {
             queue->receivedBufferDataPackets++;
         }
         
@@ -326,7 +323,7 @@ PRTPFEC_QUEUE_ENTRY RtpfGetQueuedPacket(PRTP_FEC_QUEUE queue) {
             continue;
         }
         
-        if (queuedEntry == NULL || isBefore(entry->packet->sequenceNumber, lowestRtpSequenceNumber)) {
+        if (queuedEntry == NULL || isBefore16(entry->packet->sequenceNumber, lowestRtpSequenceNumber)) {
             lowestRtpSequenceNumber = entry->packet->sequenceNumber;
             queuedEntry = entry;
         }

src/RtpReorderQueue.c

@@ -19,23 +19,18 @@ void RtpqCleanupQueue(PRTP_REORDER_QUEUE queue) {
 
 // newEntry is contained within the packet buffer so we free the whole entry by freeing entry->packet
 static int queuePacket(PRTP_REORDER_QUEUE queue, PRTP_QUEUE_ENTRY newEntry, int head, PRTP_PACKET packet) {
-    if (queue->nextRtpSequenceNumber != UINT16_MAX) {
+    PRTP_QUEUE_ENTRY entry;
-        PRTP_QUEUE_ENTRY entry;
 
-        // Don't queue packets we're already ahead of
+    LC_ASSERT(!isBefore16(packet->sequenceNumber, queue->nextRtpSequenceNumber));
-        if (isBeforeSignedInt(packet->sequenceNumber, queue->nextRtpSequenceNumber, 0)) {
+
+    // Don't queue duplicates
+    entry = queue->queueHead;
+    while (entry != NULL) {
+        if (entry->packet->sequenceNumber == packet->sequenceNumber) {
             return 0;
         }
 
-        // Don't queue duplicates either
+        entry = entry->next;
-        entry = queue->queueHead;
-        while (entry != NULL) {
-            if (entry->packet->sequenceNumber == packet->sequenceNumber) {
-                return 0;
-            }
-
-            entry = entry->next;
-        }
     }
 
     newEntry->packet = packet;
@@ -93,7 +88,7 @@ static PRTP_QUEUE_ENTRY getEntryByLowestSeq(PRTP_REORDER_QUEUE queue) {
     lowestSeqEntry = queue->queueHead;
     entry = queue->queueHead;
     while (entry != NULL) {
-        if (isBeforeSignedInt(entry->packet->sequenceNumber, lowestSeqEntry->packet->sequenceNumber, 1)) {
+        if (isBefore16(entry->packet->sequenceNumber, lowestSeqEntry->packet->sequenceNumber)) {
             lowestSeqEntry = entry;
         }
 
@@ -163,7 +158,7 @@ static PRTP_QUEUE_ENTRY validateQueueConstraints(PRTP_REORDER_QUEUE queue) {
 
 int RtpqAddPacket(PRTP_REORDER_QUEUE queue, PRTP_PACKET packet, PRTP_QUEUE_ENTRY packetEntry) {
     if (queue->nextRtpSequenceNumber != UINT16_MAX &&
-        isBeforeSignedInt(packet->sequenceNumber, queue->nextRtpSequenceNumber, 0)) {
+        isBefore16(packet->sequenceNumber, queue->nextRtpSequenceNumber)) {
         // Reject packets behind our current sequence number
         return RTPQ_RET_REJECTED;
     }

src/Video.h

@@ -17,8 +17,8 @@ int getNextQueuedDecodeUnit(PQUEUED_DECODE_UNIT* qdu);
 #define FLAG_SOF 0x4
 
 typedef struct _NV_VIDEO_PACKET {
-    int streamPacketIndex;
+    unsigned int streamPacketIndex;
-    int frameIndex;
+    unsigned int frameIndex;
     char flags;
     char reserved[3];
     int fecInfo;

src/VideoDepacketizer.c

@@ -6,19 +6,17 @@
 static PLENTRY nalChainHead;
 static int nalChainDataLength;
 
-static int nextFrameNumber;
+static unsigned int nextFrameNumber;
-static int startFrameNumber;
+static unsigned int startFrameNumber;
 static int waitingForNextSuccessfulFrame;
 static int waitingForIdrFrame;
-static int lastPacketInStream;
+static unsigned int lastPacketInStream;
 static int decodingFrame;
 static int strictIdrFrameWait;
 static unsigned long long firstPacketReceiveTime;
 
-#define TRUNCATE_24BIT(x) ((x) & 0xFFFFFF)
-
 #define CONSECUTIVE_DROP_LIMIT 120
-static int consecutiveFrameDrops;
+static unsigned int consecutiveFrameDrops;
 
 static LINKED_BLOCKING_QUEUE decodeUnitQueue;
 
@@ -38,7 +36,7 @@ void initializeVideoDepacketizer(int pktSize) {
     startFrameNumber = 0;
     waitingForNextSuccessfulFrame = 0;
     waitingForIdrFrame = 1;
-    lastPacketInStream = -1;
+    lastPacketInStream = UINT32_MAX;
     decodingFrame = 0;
     firstPacketReceiveTime = 0;
     strictIdrFrameWait = !isReferenceFrameInvalidationEnabled();
@@ -441,8 +439,8 @@ void processRtpPayload(PNV_VIDEO_PACKET videoPacket, int length, unsigned long l
     BUFFER_DESC currentPos;
     int frameIndex;
     char flags;
-    int firstPacket;
+    unsigned int firstPacket;
-    int streamPacketIndex;
+    unsigned int streamPacketIndex;
 
     // Mask the top 8 bits from the SPI
     videoPacket->streamPacketIndex >>= 8;
@@ -459,8 +457,8 @@ void processRtpPayload(PNV_VIDEO_PACKET videoPacket, int length, unsigned long l
     streamPacketIndex = videoPacket->streamPacketIndex;
     
     // The packets and frames must be in sequence from the FEC queue
-    LC_ASSERT(!isBeforeSignedInt(streamPacketIndex, TRUNCATE_24BIT(lastPacketInStream + 1), 0));
+    LC_ASSERT(!isBefore24(streamPacketIndex, U24(lastPacketInStream + 1)));
-    LC_ASSERT(!isBeforeSignedInt(frameIndex, nextFrameNumber, 0));
+    LC_ASSERT(!isBefore32(frameIndex, nextFrameNumber));
 
     // Notify the listener of the latest frame we've seen from the PC
     connectionSawFrame(frameIndex);
@@ -472,7 +470,7 @@ void processRtpPayload(PNV_VIDEO_PACKET videoPacket, int length, unsigned long l
     // miss one in between
     if (firstPacket) {
         // Make sure this is the next consecutive frame
-        if (isBeforeSignedInt(nextFrameNumber, frameIndex, 1)) {
+        if (isBefore32(nextFrameNumber, frameIndex)) {
             Limelog("Network dropped an entire frame\n");
             nextFrameNumber = frameIndex;
 
@@ -491,7 +489,7 @@ void processRtpPayload(PNV_VIDEO_PACKET videoPacket, int length, unsigned long l
 
     // This must be the first packet in a frame or be contiguous with the last
     // packet received.
-    LC_ASSERT(firstPacket || streamPacketIndex == TRUNCATE_24BIT(lastPacketInStream + 1));
+    LC_ASSERT(firstPacket || streamPacketIndex == U24(lastPacketInStream + 1));
 
     lastPacketInStream = streamPacketIndex;