WebAudio AudioDecoder IDL definitions

Add IDL for AudioDecoder and associated IO/callbacks/init.

Bug: 1094087
Change-Id: I9dca7ab13a8feeaabb8714faa37df5c901789cc4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2255142
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Auto-Submit: Chrome Cunningham <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781598}

third_party/blink/renderer/modules/webcodecs/audio_decoder.idl

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://github.com/WICG/web-codecs
+
+[
+    Exposed=(Window,Worker),
+    RuntimeEnabled=WebCodecs
+] interface AudioDecoder {
+  // |init| includes an |output| callback for emitting AudioBuffers and an
+  // |error| callback for emitting decode errors. All errors are permanent;
+  // construct a new decoder to recover.
+  //
+  // TODO(sandersd): Consider adding a state or last error attribute.
+  [CallWith=ScriptState, RaisesException] constructor(AudioDecoderInit init);
+
+  // The number of pending decode requests. This does not include requests that
+  // have been sent to the underlying codec.
+  //
+  // Applications can minimize underflow by enqueueing decode requests until
+  // |decodeQueueSize| is greater than a constant.
+  readonly attribute long decodeQueueSize;
+
+  // Set the stream configuration for future decode() requests.
+  //
+  // The next decode request must be for a keyframe.
+  //
+  // TODO(chcunningham): Move the keyframe rule into the bytestream registry.
+  [RaisesException] void configure(EncodedAudioConfig config);
+
+  // Request decoding of an input chunk.
+  //
+  // You must call configure() before calling decode() for the first time.
+  //
+  // TODO(chcunningham): Change to a dictionary type.
+  [RaisesException] void decode(EncodedAudioChunk chunk);
+
+  // Request output from all previous decode requests.
+  //
+  // Resolved after all output for earlier decode requests has been emitted.
+  //
+  // The next decode request must be for a keyframe.
+  //
+  // TODO(chcunningham): Consider relaxing the keyframe requirement.
+  // TODO(chcunningham): Indicate whether the flush() completed successfully or due
+  // to a reset.
+  [RaisesException] Promise<void> flush();
+
+  // Reset all codec state, including all pending requests.
+  //
+  // You must call configure() before submitting the next decode.
+  [RaisesException] void reset();
+
+  // Immediately shut down the decoder and free its resources. All pending
+  // decode requests are aborted.
+  //
+  // Not recoverable: make a new AudioDecoder if needed.
+  void close();
+};

third_party/blink/renderer/modules/webcodecs/audio_decoder_init.idl

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://github.com/WICG/web-codecs
+
+dictionary AudioDecoderInit {
+  AudioFrameOutputCallback output;
+  WebCodecsErrorCallback error;
+};

third_party/blink/renderer/modules/webcodecs/audio_frame.idl

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://github.com/WICG/web-codecs
+[
+    Exposed=(Window,Worker),
+    RuntimeEnabled=WebCodecs
+] interface AudioFrame {
+  [RaisesException] constructor(AudioFrameInit init);
+
+  void close();
+
+  readonly attribute unsigned long long timestamp;  // microseconds
+  readonly attribute AudioBuffer buffer;
+};

third_party/blink/renderer/modules/webcodecs/audio_frame_init.idl

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://github.com/WICG/web-codecs
+
+dictionary AudioFrameInit {
+  unsigned long long timestamp;  // microseconds
+  AudioBuffer buffer;
+};
\ No newline at end of file

third_party/blink/renderer/modules/webcodecs/audio_frame_output_callback.idl

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://github.com/WICG/web-codecs
+
+[RuntimeEnabled=WebCodecs]
+callback AudioFrameOutputCallback = void(AudioFrame output);

third_party/blink/renderer/modules/webcodecs/encoded_audio_chunk.idl

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+enum EncodedAudioChunkType {
+    "key",
+    "delta",
+};
+
+[
+    Exposed=(Window,Worker),
+    RuntimeEnabled=WebCodecs
+] interface EncodedAudioChunk {
+  constructor(EncodedAudioChunkType type, unsigned long long timestamp, BufferSource data);
+  readonly attribute EncodedAudioChunkType type;
+  readonly attribute unsigned long long timestamp;  // microseconds
+  readonly attribute ArrayBuffer data;
+};

third_party/blink/renderer/modules/webcodecs/encoded_audio_config.idl

+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://github.com/WICG/web-codecs
+
+dictionary EncodedAudioConfig {
+  // TODO(chcunningham): reference spec registry.
+  required DOMString codec;
+
+  // 44100, 48000, etc.
+  unsigned long samplesPerSecond;
+
+  // 1, 2, etc.
+  unsigned long numChannels;
+
+  // Optional byte data required to initialize audio decoders such as Vorbis
+  // codebooks.
+  BufferSource extraData;
+};