Update rtpAnalyze matlab tool to handle reordered packets

tools/matlab/rtpAnalyze.m

 function rtpAnalyze( input_file )
 %RTP_ANALYZE Analyze RTP stream(s) from a txt file
 %   The function takes the output from the command line tool rtp_analyze
 %   and analyzes the stream(s) therein. First, process your rtpdump file
 %   through rtp_analyze (from command line):
 %   $ out/Debug/rtp_analyze my_file.rtp my_file.txt
 %   Then load it with this function (in Matlab):
 %   >> rtpAnalyze('my_file.txt')
 
 % Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
@@ skipping 47 matching lines @@
 uPT = unique(PT);
 if length(uPT) > 1
     warning('This tool cannot yet handle changes in codec sample rate');
 end
 fprintf('Payload type(s): %i', uPT(1));
 if length(uPT) > 1
     fprintf(', %i', uPT(2:end));
 end
 fprintf('\n');
 fprintf('Packets: %i\n', length(SeqNo));
+SortSeqNo = sort(SeqNoUW);
 fprintf('Missing sequence numbers: %i\n', ...
-    length(find(diff(sort(SeqNoUW)) > 1)));
-fprintf('Reordered packets: %i\n', length(find(diff(sort(SeqNoUW)) < 1)));
+    length(find(diff(SortSeqNo) > 1)));
+fprintf('Duplicated packets: %i\n', length(find(diff(SortSeqNo) == 0)));
+reorderIx = findReorderedPackets(SeqNoUW);
+fprintf('Reordered packets: %i\n', length(reorderIx));
 tsdiff = diff(TimeStampUW);
 tsdiff = tsdiff(diff(SeqNoUW) == 1);
 [utsdiff, ~, ixtsdiff] = unique(tsdiff);
 fprintf('Common packet sizes:\n');
 for i = 1:length(utsdiff)
     fprintf('  %i samples (%i%%)\n', ...
         utsdiff(i), ...
         round(100 * length(find(ixtsdiff == i))/length(ixtsdiff)));
 end
 
@@ skipping 29 matching lines @@
 
 fprintf('Sent average bitrate: %i kbps\n', ...
     round(sum(Size) * 8 / (SendTimeMs(end)-SendTimeMs(1))));
 
 fprintf('Received average bitrate: %i kbps\n', ...
     round(sum(Size) * 8 / (ArrTime(end)-ArrTime(1))));
 
 %% Plots.
 delay = ArrTime - SendTimeMs;
 delay = delay - min(delay);
+delayOrdered = delay;
+delayOrdered(reorderIx) = nan;  % Set reordered packets to NaN.
+delayReordered = delay(reorderIx);  % Pick the reordered packets.
+sendTimeMsReordered = SendTimeMs(reorderIx);
+
+% Sort time arrays in packet send order.
+[~, sortix] = sort(SeqNoUW);
+SendTimeMs = SendTimeMs(sortix);
+Size = Size(sortix);
+delayOrdered = delayOrdered(sortix);
+
 figure
-plot(SendTimeMs / 1000, delay);
+plot(SendTimeMs / 1000, delayOrdered, ...
+    sendTimeMsReordered / 1000, delayReordered, 'r.');
 xlabel('Send time [s]');
 ylabel('Relative transport delay [ms]');
 title(sprintf('SSRC: %s', SSRC{1}));
 
 SendBitrateKbps = 8 * Size(1:end-1) ./ diff(SendTimeMs);
 figure
 plot(SendTimeMs(1:end-1)/1000, SendBitrateKbps);
 xlabel('Send time [s]');
 ylabel('Send bitrate [kbps]');
 end
 
+%% Subfunctions.
+
+% findReorderedPackets returns the index to all packets that are considered
+% old compared with the largest seen sequence number. The input seqNo must
+% be unwrapped for this to work.
+function reorderIx = findReorderedPackets(seqNo)
+largestSeqNo = seqNo(1);
+reorderIx = [];
+for i = 2:length(seqNo)
+    if seqNo(i) < largestSeqNo
+        reorderIx = [reorderIx; i]; %#ok<AGROW>
+    else
+        largestSeqNo = seqNo(i);
+    end
+end
+end
+
 %% Auto-generated subfunction.
 function [SeqNo,TimeStamp,SendTime,Size,PT,M,SSRC] = ...
     importfile(filename, startRow, endRow)
 %IMPORTFILE Import numeric data from a text file as column vectors.
 %   [SEQNO,TIMESTAMP,SENDTIME,SIZE,PT,M,SSRC] = IMPORTFILE(FILENAME) Reads
 %   data from text file FILENAME for the default selection.
 %
 %   [SEQNO,TIMESTAMP,SENDTIME,SIZE,PT,M,SSRC] = IMPORTFILE(FILENAME,
 %   STARTROW, ENDROW) Reads data from rows STARTROW through ENDROW of text
 %   file FILENAME.
@@ skipping 55 matching lines @@
 %% Allocate imported array to column variable names
 SeqNo = dataArray{:, 1};
 TimeStamp = dataArray{:, 2};
 SendTime = dataArray{:, 3};
 Size = dataArray{:, 4};
 PT = dataArray{:, 5};
 M = dataArray{:, 6};
 SSRC = dataArray{:, 7};
 end