Do not throw errors in copyFromChannel/copyToChannel

If the buffer offset lies outside the boundaries of the AudioBuffer , silently
do nothing instead of throwing an error.

This is a change in behavior where we used to throw an error if the offset was greater
than or equal to the size of the AudioBuffer.

Spec issue: https://github.com/WebAudio/web-audio-api/issues/1884

Bug: 987295
Change-Id: I61955108af0fa3072a2c7174889827781c06747e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1717185Reviewed-by: Hongchan Choi <hongchan@chromium.org>
Commit-Queue: Raymond Toy <rtoy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682321}

third_party/blink/renderer/modules/webaudio/audio_buffer.cc

@@ -236,7 +236,7 @@ void AudioBuffer::copyFromChannel(NotShared<DOMFloat32Array> destination,
 
 void AudioBuffer::copyFromChannel(NotShared<DOMFloat32Array> destination,
                                   int32_t channel_number,
-                                  uint32_t start_in_channel,
+                                  uint32_t buffer_offset,
                                   ExceptionState& exception_state) {
   if (channel_number < 0 ||
       static_cast<uint32_t>(channel_number) >= channels_.size()) {
@@ -253,18 +253,13 @@ void AudioBuffer::copyFromChannel(NotShared<DOMFloat32Array> destination,
 
   DOMFloat32Array* channel_data = channels_[channel_number].Get();
 
-  if (start_in_channel >= channel_data->length()) {
-    exception_state.ThrowDOMException(
-        DOMExceptionCode::kIndexSizeError,
-        ExceptionMessages::IndexOutsideRange(
-            "startInChannel", start_in_channel, 0U,
-            ExceptionMessages::kInclusiveBound, channel_data->length(),
-            ExceptionMessages::kExclusiveBound));
-
+  if (buffer_offset >= channel_data->length()) {
+    // Nothing to copy if the buffer offset is past the end of the AudioBuffer.
     return;
   }
 
-  unsigned count = channel_data->length() - start_in_channel;
+  unsigned int count = channel_data->length() - buffer_offset;
+
   count = std::min(destination.View()->length(), count);
 
   const float* src = channel_data->Data();
@@ -272,8 +267,10 @@ void AudioBuffer::copyFromChannel(NotShared<DOMFloat32Array> destination,
 
   DCHECK(src);
   DCHECK(dst);
+  DCHECK_LE(count, channel_data->length());
+  DCHECK_LE(buffer_offset + count, channel_data->length());
 
-  memcpy(dst, src + start_in_channel, count * sizeof(*src));
+  memcpy(dst, src + buffer_offset, count * sizeof(*src));
 }
 
 void AudioBuffer::copyToChannel(NotShared<DOMFloat32Array> source,
@@ -284,7 +281,7 @@ void AudioBuffer::copyToChannel(NotShared<DOMFloat32Array> source,
 
 void AudioBuffer::copyToChannel(NotShared<DOMFloat32Array> source,
                                 int32_t channel_number,
-                                uint32_t start_in_channel,
+                                uint32_t buffer_offset,
                                 ExceptionState& exception_state) {
   if (channel_number < 0 ||
       static_cast<uint32_t>(channel_number) >= channels_.size()) {
@@ -300,27 +297,23 @@ void AudioBuffer::copyToChannel(NotShared<DOMFloat32Array> source,
 
   DOMFloat32Array* channel_data = channels_[channel_number].Get();
 
-  if (start_in_channel >= channel_data->length()) {
-    exception_state.ThrowDOMException(
-        DOMExceptionCode::kIndexSizeError,
-        ExceptionMessages::IndexOutsideRange(
-            "startInChannel", start_in_channel, 0U,
-            ExceptionMessages::kInclusiveBound, channel_data->length(),
-            ExceptionMessages::kExclusiveBound));
-
+  if (buffer_offset >= channel_data->length()) {
+    // Nothing to copy if the buffer offset is past the end of the AudioBuffer.
     return;
   }
 
-  unsigned count = channel_data->length() - start_in_channel;
-  count = std::min(source.View()->length(), count);
+  unsigned int count = channel_data->length() - buffer_offset;
 
+  count = std::min(source.View()->length(), count);
   const float* src = source.View()->Data();
   float* dst = channel_data->Data();
 
   DCHECK(src);
   DCHECK(dst);
+  DCHECK_LE(buffer_offset + count, channel_data->length());
+  DCHECK_LE(count, source.View()->length());
 
-  memcpy(dst + start_in_channel, src, count * sizeof(*dst));
+  memcpy(dst + buffer_offset, src, count * sizeof(*dst));
 }
 
 void AudioBuffer::Zero() {

third_party/blink/renderer/modules/webaudio/audio_buffer.h

@@ -95,14 +95,14 @@ class MODULES_EXPORT AudioBuffer final : public ScriptWrappable {
                        ExceptionState&);
   void copyFromChannel(NotShared<DOMFloat32Array>,
                        int32_t channel_number,
-                       uint32_t start_in_channel,
+                       uint32_t buffer_offset,
                        ExceptionState&);
   void copyToChannel(NotShared<DOMFloat32Array>,
                      int32_t channel_number,
                      ExceptionState&);
   void copyToChannel(NotShared<DOMFloat32Array>,
                      int32_t channel_number,
-                     uint32_t start_in_channel,
+                     uint32_t buffer_offset,
                      ExceptionState&);
 
   void Zero();

third_party/blink/renderer/modules/webaudio/audio_buffer.idl

@@ -40,6 +40,6 @@
     // Channel access
     readonly attribute unsigned long numberOfChannels;
     [HighEntropy, Measure, RaisesException] Float32Array getChannelData(unsigned long channelIndex);
-    [HighEntropy, Measure, RaisesException] void copyFromChannel(Float32Array destination, long channelNumber, optional unsigned long startInChannel = 0);
-    [RaisesException] void copyToChannel(Float32Array source, long channelNumber, optional unsigned long startInChannel = 0);
+    [HighEntropy, Measure, RaisesException] void copyFromChannel(Float32Array destination, long channelNumber, optional unsigned long bufferOffset = 0);
+    [RaisesException] void copyToChannel(Float32Array source, long channelNumber, optional unsigned long bufferOffset = 0);
 };

third_party/blink/web_tests/external/wpt/webaudio/the-audio-api/the-audiobuffer-interface/audiobuffer-copy-channel-expected.txt

-This is a testharness.js-based test.
-Found 56 tests; 51 PASS, 5 FAIL, 0 TIMEOUT, 0 NOTRUN.
-PASS # AUDIT TASK RUNNER STARTED.
-PASS > [initialize] 
-PASS   Initialized values contains only the constant -1.
-PASS < [initialize] All assertions passed. (total 1 assertions)
-PASS > [copyFrom-exceptions] 
-PASS   AudioBuffer.prototype.copyFromChannel does exist.
-PASS   0: buffer = context.createBuffer(3, 16, context.sampleRate) did not throw an exception.
-PASS   1: buffer.copyFromChannel(null, 0) threw TypeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': parameter 1 is not of type 'Float32Array'.".
-PASS   2: buffer.copyFromChannel(context, 0) threw TypeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': parameter 1 is not of type 'Float32Array'.".
-PASS   3: buffer.copyFromChannel(x, -1) threw IndexSizeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': The channelNumber provided (-1) is outside the range [0, 2].".
-PASS   4: buffer.copyFromChannel(x, 3) threw IndexSizeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': The channelNumber provided (3) is outside the range [0, 2].".
-PASS   5: buffer.copyFromChannel(x, 0, -1) threw IndexSizeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': The startInChannel provided (4294967295) is outside the range [0, 16).".
-FAIL X 6: buffer.copyFromChannel(x, 0, 16) incorrectly threw IndexSizeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': The startInChannel provided (16) is outside the range [0, 16).". assert_true: expected true got false
-PASS   7: buffer.copyFromChannel(x, 3) threw IndexSizeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': The channelNumber provided (3) is outside the range [0, 2].".
-PASS   8: buffer.copyFromChannel(SharedArrayBuffer view, 0) threw TypeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': The provided ArrayBufferView value must not be shared.".
-PASS   9: buffer.copyFromChannel(SharedArrayBuffer view, 0, 0) threw TypeError: "Failed to execute 'copyFromChannel' on 'AudioBuffer': The provided ArrayBufferView value must not be shared.".
-FAIL < [copyFrom-exceptions] 1 out of 11 assertions were failed. assert_true: expected true got false
-PASS > [copyTo-exceptions] 
-PASS   AudioBuffer.prototype.copyToChannel does exist.
-PASS   0: buffer.copyToChannel(null, 0) threw TypeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': parameter 1 is not of type 'Float32Array'.".
-PASS   1: buffer.copyToChannel(context, 0) threw TypeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': parameter 1 is not of type 'Float32Array'.".
-PASS   2: buffer.copyToChannel(x, -1) threw IndexSizeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': The channelNumber provided (-1) is outside the range [0, 2].".
-PASS   3: buffer.copyToChannel(x, 3) threw IndexSizeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': The channelNumber provided (3) is outside the range [0, 2].".
-PASS   4: buffer.copyToChannel(x, 0, -1) threw IndexSizeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': The startInChannel provided (4294967295) is outside the range [0, 16).".
-FAIL X 5: buffer.copyToChannel(x, 0, 16) incorrectly threw IndexSizeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': The startInChannel provided (16) is outside the range [0, 16).". assert_true: expected true got false
-PASS   6: buffer.copyToChannel(x, 3) threw IndexSizeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': The channelNumber provided (3) is outside the range [0, 2].".
-PASS   7: buffer.copyToChannel(SharedArrayBuffer view, 0) threw TypeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': The provided ArrayBufferView value must not be shared.".
-PASS   8: buffer.copyToChannel(SharedArrayBuffer view, 0, 0) threw TypeError: "Failed to execute 'copyToChannel' on 'AudioBuffer': The provided ArrayBufferView value must not be shared.".
-FAIL < [copyTo-exceptions] 1 out of 10 assertions were failed. assert_true: expected true got false
-PASS > [copyFrom-validate] 
-PASS   buffer.copyFromChannel(dst8, 0) is identical to the array [1,2,3,4,5,6,7,8].
-PASS   buffer.copyFromChannel(dst8, 1) is identical to the array [2,3,4,5,6,7,8,9].
-PASS   buffer.copyFromChannel(dst8, 2) is identical to the array [3,4,5,6,7,8,9,10].
-PASS   buffer.copyFromChannel(dst8, 0, 1) is identical to the array [2,3,4,5,6,7,8,9].
-PASS   buffer.copyFromChannel(dst8, 1, 1) is identical to the array [3,4,5,6,7,8,9,10].
-PASS   buffer.copyFromChannel(dst8, 2, 1) is identical to the array [4,5,6,7,8,9,10,11].
-PASS   buffer.copyFromChannel(dst8, 0, 11) is identical to the array [12,13,14,15,16,-1,-1,-1].
-PASS   buffer.copyFromChannel(dst8, 1, 11) is identical to the array [13,14,15,16,17,-1,-1,-1].
-PASS   buffer.copyFromChannel(dst8, 2, 11) is identical to the array [14,15,16,17,18,-1,-1,-1].
-PASS   buffer.copyFromChannel(dst26, 0) is identical to the array [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16...].
-PASS   buffer.copyFromChannel(dst26, 1) is identical to the array [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17...].
-PASS   buffer.copyFromChannel(dst26, 2) is identical to the array [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18...].
-PASS < [copyFrom-validate] All assertions passed. (total 12 assertions)
-PASS > [copyTo-validate] 
-PASS   buffer = createConstantBuffer(context, 16, [-1,-1,-1]) did not throw an exception.
-PASS   buffer.copyToChannel(src, 0) is identical to the array [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16...].
-PASS   buffer.copyToChannel(src, 1) is identical to the array [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16...].
-PASS   buffer.copyToChannel(src, 2) is identical to the array [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16...].
-PASS   buffer.copyToChannel(src10, 0) is identical to the array [1,2,3,4,5,6,7,8,9,10,-1,-1,-1,-1,-1,-1...].
-PASS   buffer.copyToChannel(src10, 1) is identical to the array [1,2,3,4,5,6,7,8,9,10,-1,-1,-1,-1,-1,-1...].
-PASS   buffer.copyToChannel(src10, 2) is identical to the array [1,2,3,4,5,6,7,8,9,10,-1,-1,-1,-1,-1,-1...].
-PASS   buffer.copyToChannel(src10, 0, 5) is identical to the array [-1,-1,-1,-1,-1,1,2,3,4,5,6,7,8,9,10,-1...].
-PASS   buffer.copyToChannel(src10, 1, 5) is identical to the array [-1,-1,-1,-1,-1,1,2,3,4,5,6,7,8,9,10,-1...].
-PASS   buffer.copyToChannel(src10, 2, 5) is identical to the array [-1,-1,-1,-1,-1,1,2,3,4,5,6,7,8,9,10,-1...].
-PASS < [copyTo-validate] All assertions passed. (total 10 assertions)
-FAIL # AUDIT TASK RUNNER FINISHED: 2 out of 5 tasks were failed. assert_true: expected true got false
-Harness: the test ran to completion.
-

third_party/blink/web_tests/external/wpt/webaudio/the-audio-api/the-audiobuffer-interface/audiobuffer-copy-channel.html

@@ -137,7 +137,7 @@
         ;
         should(() => {
           buffer.copyFromChannel(x, 0, -1);
-        }, '5: buffer.copyFromChannel(x, 0, -1)').throw(DOMException, 'IndexSizeError');
+        }, '5: buffer.copyFromChannel(x, 0, -1)').notThrow();
         should(
             () => {
               buffer.copyFromChannel(x, 0, bufferLength);
@@ -192,7 +192,7 @@
             .throw(DOMException, 'IndexSizeError');
         should(() => {
           buffer.copyToChannel(x, 0, -1);
-        }, '4: buffer.copyToChannel(x, 0, -1)').throw(DOMException, 'IndexSizeError');
+        }, '4: buffer.copyToChannel(x, 0, -1)').notThrow();
         should(
             () => {
               buffer.copyToChannel(x, 0, bufferLength);