fix error with audio- or video-only streams. Closes #348

@@ -3,6 +3,7 @@ CHANGELOG
 
 ## HEAD (Unreleased)
 * do not assume media sequence starts at zero ([view](https://github.com/videojs/videojs-contrib-hls/pull/346))
+* fix error with audio- or video-only streams ([view](https://github.com/videojs/videojs-contrib-hls/pull/348))
 
 --------------------
 

@@ -5,7 +5,23 @@
   'use strict';
 
   var DEFAULT_TARGET_DURATION = 10;
-  var accumulateDuration, ascendingNumeric, duration, intervalDuration, rangeDuration, seekable;
+  var accumulateDuration, ascendingNumeric, duration, intervalDuration, optionalMin, optionalMax, rangeDuration, seekable;
+
+  // Math.min that will return the alternative input if one of its
+  // parameters in undefined
+  optionalMin = function(left, right) {
+    left = isFinite(left) ? left : Infinity;
+    right = isFinite(right) ? right : Infinity;
+    return Math.min(left, right);
+  };
+
+  // Math.max that will return the alternative input if one of its
+  // parameters in undefined
+  optionalMax = function(left, right) {
+    left = isFinite(left) ? left: -Infinity;
+    right = isFinite(right) ? right: -Infinity;
+    return Math.max(left, right);
+  };
 
   // Array.sort comparator to sort numbers in ascending order
   ascendingNumeric = function(left, right) {
@@ -91,7 +107,8 @@
     // available PTS information
     for (left = range.start; left < range.end; left++) {
       segment = playlist.segments[left];
-      if (segment.minVideoPts !== undefined) {
+      if (segment.minVideoPts !== undefined ||
+          segment.minAudioPts !== undefined) {
         break;
       }
       result += segment.duration || targetDuration;
@@ -100,10 +117,12 @@
     // see if there's enough information to include the trailing time
     if (includeTrailingTime) {
       segment = playlist.segments[range.end];
-      if (segment && segment.minVideoPts !== undefined) {
+      if (segment &&
+          (segment.minVideoPts !== undefined ||
+           segment.minAudioPts !== undefined)) {
         result += 0.001 *
-          (Math.min(segment.minVideoPts, segment.minAudioPts) -
-           Math.min(playlist.segments[left].minVideoPts,
+          (optionalMin(segment.minVideoPts, segment.minAudioPts) -
+           optionalMin(playlist.segments[left].minVideoPts,
                     playlist.segments[left].minAudioPts));
         return result;
       }
@@ -112,7 +131,8 @@
     // do the same thing while finding the latest segment
     for (right = range.end - 1; right >= left; right--) {
       segment = playlist.segments[right];
-      if (segment.maxVideoPts !== undefined) {
+      if (segment.maxVideoPts !== undefined ||
+          segment.maxAudioPts !== undefined) {
         break;
       }
       result += segment.duration || targetDuration;
@@ -121,9 +141,9 @@
     // add in the PTS interval in seconds between them
     if (right >= left) {
       result += 0.001 *
-        (Math.max(playlist.segments[right].maxVideoPts,
+        (optionalMax(playlist.segments[right].maxVideoPts,
                   playlist.segments[right].maxAudioPts) -
-         Math.min(playlist.segments[left].minVideoPts,
+         optionalMin(playlist.segments[left].minVideoPts,
                   playlist.segments[left].minAudioPts));
     }
 
@@ -158,7 +178,7 @@
     targetDuration = playlist.targetDuration || DEFAULT_TARGET_DURATION;
 
     // estimate expired segment duration using the target duration
-    expiredSegmentCount = Math.max(playlist.mediaSequence - startSequence, 0);
+    expiredSegmentCount = optionalMax(playlist.mediaSequence - startSequence, 0);
     result += expiredSegmentCount * targetDuration;
 
     // accumulate the segment durations into the result
@@ -257,9 +277,9 @@
       // from the result.
       for (i = playlist.segments.length - 1; i >= 0 && liveBuffer > 0; i--) {
         segment = playlist.segments[i];
-        pending = Math.min(duration(playlist,
-                                    playlist.mediaSequence + i,
-                                    playlist.mediaSequence + i + 1),
+        pending = optionalMin(duration(playlist,
+                                       playlist.mediaSequence + i,
+                                       playlist.mediaSequence + i + 1),
                            liveBuffer);
         liveBuffer -= pending;
         end -= pending;

@@ -899,10 +899,14 @@ videojs.Hls.prototype.drainBuffer = function(event) {
   if (this.segmentParser_.tagsAvailable()) {
     // record PTS information for the segment so we can calculate
     // accurate durations and seek reliably
-    segment.minVideoPts = this.segmentParser_.stats.minVideoPts();
-    segment.maxVideoPts = this.segmentParser_.stats.maxVideoPts();
-    segment.minAudioPts = this.segmentParser_.stats.minAudioPts();
-    segment.maxAudioPts = this.segmentParser_.stats.maxAudioPts();
+    if (this.segmentParser_.stats.h264Tags()) {
+      segment.minVideoPts = this.segmentParser_.stats.minVideoPts();
+      segment.maxVideoPts = this.segmentParser_.stats.maxVideoPts();
+    }
+    if (this.segmentParser_.stats.aacTags()) {
+      segment.minAudioPts = this.segmentParser_.stats.minAudioPts();
+      segment.maxAudioPts = this.segmentParser_.stats.maxAudioPts();
+    }
   }
 
   while (this.segmentParser_.tagsAvailable()) {

@@ -259,6 +259,30 @@
     equal(duration, 30.1, 'used the PTS-based interval');
   });
 
+  test('works for media without audio', function() {
+    equal(Playlist.duration({
+      mediaSequence: 0,
+      endList: true,
+      segments: [{
+        minVideoPts: 0,
+        maxVideoPts: 9 * 1000,
+        uri: 'no-audio.ts'
+      }]
+    }), 9, 'used video PTS values');
+  });
+
+  test('works for media without video', function() {
+    equal(Playlist.duration({
+      mediaSequence: 0,
+      endList: true,
+      segments: [{
+        minAudioPts: 0,
+        maxAudioPts: 9 * 1000,
+        uri: 'no-video.ts'
+      }]
+    }), 9, 'used video PTS values');
+  });
+
   test('uses the largest continuous available PTS ranges', function() {
     var playlist = {
       mediaSequence: 0,

@@ -284,6 +284,17 @@
     equal(packets.length, 1, 'parsed non-payload metadata packet');
   });
 
+  test('returns undefined for PTS stats when a track is missing', function() {
+    parser.parseSegmentBinaryData(new Uint8Array(makePacket({
+      programs: {
+        0x01: [0x01]
+      }
+    })));
+
+    strictEqual(parser.stats.h264Tags(), 0, 'no video tags yet');
+    strictEqual(parser.stats.aacTags(), 0, 'no audio tags yet');
+  });
+
   test('parses the first bipbop segment', function() {
     parser.parseSegmentBinaryData(window.bcSegment);
 

@@ -121,12 +121,18 @@ var
       ]);
 
       this.stats = {
+        h264Tags: function() {
+          return tags.length;
+        },
         minVideoPts: function() {
           return tags[0].pts;
         },
         maxVideoPts: function() {
           return tags[tags.length - 1].pts;
         },
+        aacTags: function() {
+          return tags.length;
+        },
         minAudioPts: function() {
           return tags[0].pts;
         },
@@ -1044,6 +1050,64 @@ test('records the min and max PTS values for a segment', function() {
   equal(player.hls.playlists.media().segments[0].maxAudioPts, 10, 'recorded max audio pts');
 });
 
+test('records PTS values for video-only segments', function() {
+  var tags = [];
+  videojs.Hls.SegmentParser = mockSegmentParser(tags);
+  player.src({
+    src: 'manifest/media.m3u8',
+    type: 'application/vnd.apple.mpegurl'
+  });
+  openMediaSource(player);
+  standardXHRResponse(requests.pop()); // media.m3u8
+
+  player.hls.segmentParser_.stats.aacTags = function() {
+    return 0;
+  };
+  player.hls.segmentParser_.stats.minAudioPts = function() {
+    throw new Error('No audio tags');
+  };
+  player.hls.segmentParser_.stats.maxAudioPts = function() {
+    throw new Error('No audio tags');
+  };
+  tags.push({ pts: 0, bytes: new Uint8Array(1) });
+  tags.push({ pts: 10, bytes: new Uint8Array(1) });
+  standardXHRResponse(requests.pop()); // segment 0
+
+  equal(player.hls.playlists.media().segments[0].minVideoPts, 0, 'recorded min video pts');
+  equal(player.hls.playlists.media().segments[0].maxVideoPts, 10, 'recorded max video pts');
+  strictEqual(player.hls.playlists.media().segments[0].minAudioPts, undefined, 'min audio pts is undefined');
+  strictEqual(player.hls.playlists.media().segments[0].maxAudioPts, undefined, 'max audio pts is undefined');
+});
+
+test('records PTS values for audio-only segments', function() {
+  var tags = [];
+  videojs.Hls.SegmentParser = mockSegmentParser(tags);
+  player.src({
+    src: 'manifest/media.m3u8',
+    type: 'application/vnd.apple.mpegurl'
+  });
+  openMediaSource(player);
+  standardXHRResponse(requests.pop()); // media.m3u8
+
+  player.hls.segmentParser_.stats.h264Tags = function() {
+    return 0;
+  };
+  player.hls.segmentParser_.stats.minVideoPts = function() {
+    throw new Error('No video tags');
+  };
+  player.hls.segmentParser_.stats.maxVideoPts = function() {
+    throw new Error('No video tags');
+  };
+  tags.push({ pts: 0, bytes: new Uint8Array(1) });
+  tags.push({ pts: 10, bytes: new Uint8Array(1) });
+  standardXHRResponse(requests.pop()); // segment 0
+
+  equal(player.hls.playlists.media().segments[0].minAudioPts, 0, 'recorded min audio pts');
+  equal(player.hls.playlists.media().segments[0].maxAudioPts, 10, 'recorded max audio pts');
+  strictEqual(player.hls.playlists.media().segments[0].minVideoPts, undefined, 'min video pts is undefined');
+  strictEqual(player.hls.playlists.media().segments[0].maxVideoPts, undefined, 'max video pts is undefined');
+});
+
 test('waits to download new segments until the media playlist is stable', function() {
   var media;
   player.src({