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#ifndef GMP_VIDEO_DECODE_h_
#define GMP_VIDEO_DECODE_h_

#include "gmp-errors.h"
#include "gmp-video-frame-i420.h"
#include "gmp-video-frame-encoded.h"
#include "gmp-video-codec.h"
#include <stdint.h>

// ALL METHODS MUST BE CALLED ON THE MAIN THREAD
class GMPVideoDecoderCallback
{
public:
  virtual ~GMPVideoDecoderCallback() {}

  virtual void Decoded(GMPVideoi420Frame* aDecodedFrame) = 0;

  virtual void ReceivedDecodedReferenceFrame(const uint64_t aPictureId) = 0;

  virtual void ReceivedDecodedFrame(const uint64_t aPictureId) = 0;

  virtual void InputDataExhausted() = 0;

  virtual void DrainComplete() = 0;

  virtual void ResetComplete() = 0;

  // Called when the decoder encounters a catestrophic error and cannot
  // continue. Gecko will not send any more input for decoding.
  virtual void Error(GMPErr aError) = 0;
};

#define GMP_API_VIDEO_DECODER "decode-video"

// Video decoding for a single stream. A GMP may be asked to create multiple
// decoders concurrently.
//
// API name macro: GMP_API_VIDEO_DECODER
// Host API: GMPVideoHost
//
// ALL METHODS MUST BE CALLED ON THE MAIN THREAD
class GMPVideoDecoder
{
public:
  virtual ~GMPVideoDecoder() {}

  // - aCodecSettings: Details of decoder to create.
  // - aCodecSpecific: codec specific data, cast to a GMPVideoCodecXXX struct
  //                   to get codec specific config data.
  // - aCodecSpecificLength: number of bytes in aCodecSpecific.
  // - aCallback: Subclass should retain reference to it until DecodingComplete
  //              is called. Do not attempt to delete it, host retains ownership.
  // aCoreCount: number of CPU cores.
  virtual void InitDecode(const GMPVideoCodec& aCodecSettings,
                          const uint8_t* aCodecSpecific,
                          uint32_t aCodecSpecificLength,
                          GMPVideoDecoderCallback* aCallback,
                          int32_t aCoreCount) = 0;

  // Decode encoded frame (as a part of a video stream). The decoded frame
  // will be returned to the user through the decode complete callback.
  //
  // - aInputFrame: Frame to decode. Call Destroy() on frame when it's decoded.
  // - aMissingFrames: True if one or more frames have been lost since the
  //                   previous decode call.
  // - aCodecSpecificInfo : codec specific data, pointer to a
  //                        GMPCodecSpecificInfo structure appropriate for
  //                        this codec type.
  // - aCodecSpecificInfoLength : number of bytes in aCodecSpecificInfo
  // - renderTimeMs : System time to render in milliseconds. Only used by
  //                  decoders with internal rendering.
  virtual void Decode(GMPVideoEncodedFrame* aInputFrame,
                      bool aMissingFrames,
                      const uint8_t* aCodecSpecificInfo,
                      uint32_t aCodecSpecificInfoLength,
                      int64_t aRenderTimeMs = -1) = 0;

  // Reset decoder state and prepare for a new call to Decode(...).
  // Flushes the decoder pipeline.
  // The decoder should enqueue a task to run ResetComplete() on the main
  // thread once the reset has finished.
  virtual void Reset() = 0;

  // Output decoded frames for any data in the pipeline, regardless of ordering.
  // All remaining decoded frames should be immediately returned via callback.
  // The decoder should enqueue a task to run DrainComplete() on the main
  // thread once the reset has finished.
  virtual void Drain() = 0;

  // May free decoder memory.
  virtual void DecodingComplete() = 0;
};

#endif // GMP_VIDEO_DECODE_h_
