// Copyright 2014 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.

module mojo;

import "media/mojo/interfaces/demuxer_stream.mojom";
import "media/mojo/interfaces/media_types.mojom";

// TODO(xhwang): Add mojo types for AudioBuffer and VideoFrame.
struct AudioBuffer {};
struct VideoFrame {};

// Interface for decrypting (and decoding) encrypted streams.
// See media/base/decryptor.h for details.
interface Decryptor {
  // Status of a decrypt or decrypt-and-decode operation. The returned
  // buffer/frame of such an operation is NOT null iff the status is SUCCESS.
  enum Status {
    SUCCESS,  // Successfully completed. Decrypted buffer ready.
    NO_KEY,  // No key is available to decrypt.
    NEED_MORE_DATA,  // Decoder needs more data to produce an output.
    ERROR  // Key is available but an error occurred during decryption.
  };

  // Decrypts the |encrypted| buffer and returns the decrypt |status| and
  // decrypted |buffer|.
  // At most one decrypt call is allowed at any time for a |stream_type|.
  Decrypt(DemuxerStream.Type stream_type, MediaDecoderBuffer encrypted)
      => (Status status, MediaDecoderBuffer? buffer);

  // Cancels any pending decrypt for |stream_type| with SUCCESS.
  CancelDecrypt(DemuxerStream.Type stream_type);

  // Initializes a decoder with the given |config|. Returns whether the
  // initialization succeeded.
  InitializeAudioDecoder(AudioDecoderConfig config) => (bool success);
  InitializeVideoDecoder(VideoDecoderConfig config) => (bool success);

  // Decrypts and decodes the |encrypted| buffer and returns the |status| and
  // the decrypted |audio_buffers| or |video_frame|.
  // At end-of-stream, this method should be called repeatedly with
  // end-of-stream |encrypted| until no buffer/frame can be produced.
  // These methods can only be called after the corresponding decoder has
  // been successfully initialized.
  // At most one decrypt-and-decode call is allowed at any time for a
  // |stream_type|.
  DecryptAndDecodeAudio(MediaDecoderBuffer encrypted)
      => (Status status, array<AudioBuffer>? audio_buffers);
  DecryptAndDecodeVideo(
      MediaDecoderBuffer encrypted) => (Status status, VideoFrame? video_frame);

  // Resets the decoder for |stream_type| to a clean initialized state and
  // cancels any pending decrypt-and-decode operations immediately with ERROR.
  // This method can only be called after the corresponding decoder has been
  // successfully initialized.
  ResetDecoder(DemuxerStream.Type stream_type);

  // Releases decoder resources, deinitializes the decoder, aborts any pending
  // initialization (with false) or decrypt-and-decode (with ERROR) for
  // |stream_type| immediately.
  // This method can be called any time after Initialize{Audio|Video}Decoder()
  // has been called (with the correct stream type).
  // After this operation, the decoder is set to an uninitialized state.
  // The decoder can be reinitialized after it is deinitialized.
  DeinitializeDecoder(DemuxerStream.Type stream_type);
};

interface DecryptorClient {
  // Indicates that a new usable key is available in the CDM associated with the
  // Decryptor.
  OnNewUsableKey();
};