third_party/WebKit/LayoutTests/webaudio/audiochannelmerger-input.html

   1 <!DOCTYPE html>
   2 <html>
   3
   4 <head>
   5   <script src="../resources/js-test.js"></script>
   6   <script src="resources/compatibility.js"></script>
   7   <script src="resources/audio-testing.js"></script>
   8   <script src="resources/merger-testing.js"></script>
   9 </head>
  10
  11 <body>
  12   <script>
  13     description('Test input handling behavior of ChannelMergerNode.');
  14     window.jsTestIsAsync = true;
  15
  16     var audit = Audit.createTaskRunner();
  17
  18     // Task: Check if an inactive input renders a silent mono channel in the
  19     // output.
  20     audit.defineTask('silent-channel', function (done) {
  21       testMergerInput({
  22         numberOfChannels: 6,
  23
  24         // Create a mono source buffer filled with '1'.
  25         testBufferChannelCount: 1,
  26
  27         // Connect the output of source into the 4th input of merger.
  28         mergerInputIndex: 3,
  29
  30         // All channels should contain 0, except channel 4 which should be 1.
  31         expected: [0, 0, 0, 1, 0, 0],
  32       }, done);
  33     });
  34
  35
  36     // Task: Check if a stereo input is being down-mixed to mono channel
  37     // correctly based on the mixing rule.
  38     audit.defineTask('stereo-down-mixing', function (done) {
  39       testMergerInput({
  40         numberOfChannels: 6,
  41
  42         // Create a stereo buffer filled with '1' and '2' for left and right
  43         // channels respectively.
  44         testBufferChannelCount: 2,
  45
  46         // Connect the output of source into the 1st input of merger.
  47         mergerInputIndex: undefined,
  48
  49         // The result of summed and down-mixed stereo audio should be 1.5.
  50         // (= 1 * 0.5 + 2 * 0.5)
  51         expected: [1.5, 0, 0, 0, 0, 0],
  52       }, done);
  53     });
  54
  55
  56     // Task: Check if 3-channel input gets processed by the 'discrete' mixing
  57     // rule.
  58     audit.defineTask('undefined-channel-layout', function (done) {
  59       testMergerInput({
  60         numberOfChannels: 6,
  61
  62         // Create a 3-channel buffer filled with '1', '2', and '3' respectively.
  63         testBufferChannelCount: 3,
  64
  65         // Connect the output of source into the 1st input of merger.
  66         mergerInputIndex: undefined,
  67
  68         // The result of summed stereo audio should be 1 because 3-channel is
  69         // not a canonical layout, so the input channel 2 and 3 should be
  70         // dropped by 'discrete' mixing rule.
  71         expected: [1, 0, 0, 0, 0, 0],
  72       }, done);
  73     });
  74
  75
  76     // Task: Merging two inputs into a single stereo stream.
  77     audit.defineTask('merging-to-stereo', function (done) {
  78
  79       // For this test, the number of channel should be 2.
  80       var context = new OfflineAudioContext(2, 128, 44100);
  81       var merger = context.createChannelMerger();
  82       var source1 = context.createBufferSource();
  83       var source2 = context.createBufferSource();
  84
  85       // Create a DC offset buffer (mono) filled with 1 and assign it to BS
  86       // nodes.
  87       var positiveDCOffset = createConstantBuffer(context, 128, 1);
  88       var negativeDCOffset = createConstantBuffer(context, 128, -1);
  89       source1.buffer = positiveDCOffset;
  90       source2.buffer = negativeDCOffset;
  91
  92       // Connect: BS#1 => merger_input#0, BS#2 => Inverter => merger_input#1
  93       source1.connect(merger, 0, 0);
  94       source2.connect(merger, 0, 1);
  95       merger.connect(context.destination);
  96       source1.start();
  97       source2.start();
  98
  99       context.startRendering().then(function (buffer) {
 100
 101         // Channel#0 = 1, Channel#1 = -1
 102         Should('Channel #0', buffer.getChannelData(0)).beConstantValueOf(1);
 103         Should('Channel #1', buffer.getChannelData(1)).beConstantValueOf(-1);
 104
 105         done();
 106       });
 107     });
 108
 109
 110     audit.defineTask('finish', function (done) {
 111       finishJSTest();
 112       done();
 113     });
 114
 115     audit.runTasks(
 116       'silent-channel',
 117       'stereo-down-mixing',
 118       'undefined-channel-layout',
 119       'merging-to-stereo',
 120       'finish'
 121     );
 122
 123     successfullyParsed = true;
 124   </script>
 125 </body>
 126
 127 </html>