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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
| commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
| tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /dom/media/webaudio/test/test_delaynode-channel-count-1.html | |
| parent | Initial commit. (diff) | |
| download | firefox-esr-upstream.tar.xz firefox-esr-upstream.zip | |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'dom/media/webaudio/test/test_delaynode-channel-count-1.html')
| -rw-r--r-- | dom/media/webaudio/test/test_delaynode-channel-count-1.html | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/dom/media/webaudio/test/test_delaynode-channel-count-1.html b/dom/media/webaudio/test/test_delaynode-channel-count-1.html new file mode 100644 index 0000000000..dd964ef9e3 --- /dev/null +++ b/dom/media/webaudio/test/test_delaynode-channel-count-1.html @@ -0,0 +1,104 @@ +<!DOCTYPE html> +<title>Test that DelayNode output channelCount matches that of the delayed input</title> +<script src="/resources/testharness.js"></script> +<script src="/resources/testharnessreport.js"></script> +<script> +// See https://github.com/WebAudio/web-audio-api/issues/25 + +// sampleRate is a power of two so that delay times are exact in base-2 +// floating point arithmetic. +const SAMPLE_RATE = 32768; +// Arbitrary delay time in frames (but this is assumed a multiple of block +// size below): +const DELAY_FRAMES = 3 * 128; +// Implementations may apply interpolation to input samples, which can spread +// the effect of input with larger channel counts over neighbouring blocks. +// This test ignores enough neighbouring blocks to ignore the effects of +// filter radius of up to this number of frames: +const INTERPOLATION_GRACE = 128; +// Number of frames of DelayNode output that are known to be stereo: +const STEREO_FRAMES = 128; +// The delay will be increased at this frame to switch DelayNode output back +// to mono. +const MONO_OUTPUT_START_FRAME = + DELAY_FRAMES + INTERPOLATION_GRACE + STEREO_FRAMES; +// Number of frames of output that are known to be mono after the known stereo +// and interpolation grace. +const MONO_FRAMES = 128; +// Total length allows for interpolation after effects of stereo input are +// finished and one block to test return to mono output: +const TOTAL_LENGTH = + MONO_OUTPUT_START_FRAME + INTERPOLATION_GRACE + MONO_FRAMES; +// maxDelayTime, is a multiple of block size, because the Gecko implementation +// once had a bug with delayTime = maxDelayTime in this situation: +const MAX_DELAY_FRAMES = TOTAL_LENGTH + INTERPOLATION_GRACE; + +promise_test(() => { + let context = new OfflineAudioContext({numberOfChannels: 1, + length: TOTAL_LENGTH, + sampleRate: SAMPLE_RATE}); + + // Only channel 1 of the splitter is connected to the destination. + let splitter = new ChannelSplitterNode(context, {numberOfOutputs: 2}); + splitter.connect(context.destination, 1); + + // A gain node has channelCountMode "max" and channelInterpretation + // "speakers", and so will up-mix a mono input when there is stereo input. + let gain = new GainNode(context); + gain.connect(splitter); + + // The delay node initially outputs a single channel of silence, when it + // does not have enough signal in its history to output what it has + // previously received. After the delay period, it will then output the + // stereo signal it received. + let delay = + new DelayNode(context, + {maxDelayTime: MAX_DELAY_FRAMES / context.sampleRate, + delayTime: DELAY_FRAMES / context.sampleRate}); + // Schedule an increase in the delay to return to mono silent output from + // the unfilled portion of the DelayNode's buffer. + delay.delayTime.setValueAtTime(MAX_DELAY_FRAMES / context.sampleRate, + MONO_OUTPUT_START_FRAME / context.sampleRate); + delay.connect(gain); + + let stereoMerger = new ChannelMergerNode(context, {numberOfInputs: 2}); + stereoMerger.connect(delay); + + let leftOffset = 0.125; + let rightOffset = 0.5; + let leftSource = new ConstantSourceNode(context, {offset: leftOffset}); + let rightSource = new ConstantSourceNode(context, {offset: rightOffset}); + leftSource.start(); + rightSource.start(); + leftSource.connect(stereoMerger, 0, 0); + rightSource.connect(stereoMerger, 0, 1); + // Connect a mono source directly to the gain, so that even stereo silence + // will be detected in channel 1 of the gain output because it will cause + // the mono source to be up-mixed. + let monoOffset = 0.25 + let monoSource = new ConstantSourceNode(context, {offset: monoOffset}); + monoSource.start(); + monoSource.connect(gain); + + return context.startRendering(). + then((buffer) => { + let output = buffer.getChannelData(0); + + function assert_samples_equal(startIndex, length, expected, description) + { + for (let i = startIndex; i < startIndex + length; ++i) { + assert_equals(output[i], expected, description + ` at ${i}`); + } + } + + assert_samples_equal(0, DELAY_FRAMES - INTERPOLATION_GRACE, + 0, "Initial mono"); + assert_samples_equal(DELAY_FRAMES + INTERPOLATION_GRACE, STEREO_FRAMES, + monoOffset + rightOffset, "Stereo"); + assert_samples_equal(MONO_OUTPUT_START_FRAME + INTERPOLATION_GRACE, + MONO_FRAMES, + 0, "Final mono"); + }); +}); + +</script> |