summaryrefslogtreecommitdiffstats
path: root/dom/media/webaudio/test/test_sequentialBufferSourceWithResampling.html
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--dom/media/webaudio/test/test_sequentialBufferSourceWithResampling.html72
1 files changed, 72 insertions, 0 deletions
diff --git a/dom/media/webaudio/test/test_sequentialBufferSourceWithResampling.html b/dom/media/webaudio/test/test_sequentialBufferSourceWithResampling.html
new file mode 100644
index 0000000000..5c03a8a911
--- /dev/null
+++ b/dom/media/webaudio/test/test_sequentialBufferSourceWithResampling.html
@@ -0,0 +1,72 @@
+<!DOCTYPE html>
+<title>Test seamless playback of a series of resampled buffers</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+// Permitting some accumulation of rounding to int16_t.
+// 64/2^15 would be only just small enough to detect off-by-one-subsample
+// scheduling errors with the frequencies here.
+const EPSILON = 4.0 / Math.pow(2, 15);
+// Offsets test for rounding to nearest rather than up or down.
+const OFFSETS = [EPSILON, 1.0 - EPSILON];
+// The ratio of resampling is 147:160, so 256 start points is enough to cover
+// every fractional offset.
+const LENGTH = 256;
+
+function do_test(context_rate, buffer_rate, start_offset) {
+
+ var context =
+ new OfflineAudioContext(2, LENGTH, context_rate);
+
+ var merger = context.createChannelMerger(context.destination.channelCount);
+ merger.connect(context.destination);
+
+ // Create an audio signal that will be repeated
+ var repeating_signal = context.createBuffer(1, 1, buffer_rate);
+ repeating_signal.getChannelData(0)[0] = 0.5;
+
+ // Schedule a series of nodes to repeat the signal.
+ for (var i = 0; i < LENGTH; ++i) {
+ var source = context.createBufferSource();
+ source.buffer = repeating_signal;
+ source.connect(merger, 0, 0);
+ source.start((i + start_offset) / buffer_rate);
+ }
+
+ // A single long signal should produce the same result.
+ var long_signal = context.createBuffer(1, LENGTH, buffer_rate);
+ var c = long_signal.getChannelData(0);
+ for (var i = 0; i < c.length; ++i) {
+ c[i] = 0.5;
+ }
+
+ var source = context.createBufferSource();
+ source.buffer = long_signal;
+ source.connect(merger, 0, 1);
+ source.start(start_offset / buffer_rate);
+
+ return context.startRendering().
+ then((buffer) => {
+ series_output = buffer.getChannelData(0);
+ expected = buffer.getChannelData(1);
+
+ for (var i = 0; i < buffer.length; ++i) {
+ assert_approx_equals(series_output[i], expected[i], EPSILON,
+ "series output at " + i);
+ }
+ });
+}
+
+function start_tests(context_rate, buffer_rate) {
+ OFFSETS.forEach((start_offset) => {
+ promise_test(() => do_test(context_rate, buffer_rate, start_offset),
+ "" + context_rate + " context, "
+ + buffer_rate + " buffer, "
+ + start_offset + " start");
+ });
+}
+
+start_tests(48000, 44100);
+start_tests(44100, 48000);
+
+</script>