ObjC: Implement HW codecs in ObjC instead of C++

webrtc/sdk/objc/Framework/Classes/VideoToolbox/helpers.h

 /*
- *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  *
  */
 
-#ifndef WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_VIDEOTOOLBOX_DECODER_H_
-#define WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_VIDEOTOOLBOX_DECODER_H_
+#ifndef WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_VIDEOTOOLBOX_HELPERS_H_
+#define WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_VIDEOTOOLBOX_HELPERS_H_
 
-#include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
+#include <CoreFoundation/CoreFoundation.h>
+#include <VideoToolbox/VideoToolbox.h>
+#include <string>
 
-#include <VideoToolbox/VideoToolbox.h>
+// Convenience function for creating a dictionary.
+inline CFDictionaryRef CreateCFTypeDictionary(CFTypeRef* keys,
+                                              CFTypeRef* values,
+                                              size_t size) {
+  return CFDictionaryCreate(kCFAllocatorDefault, keys, values, size,
+                            &kCFTypeDictionaryKeyCallBacks,
+                            &kCFTypeDictionaryValueCallBacks);
+}
 
-// This file provides a H264 encoder implementation using the VideoToolbox
-// APIs. Since documentation is almost non-existent, this is largely based on
-// the information in the VideoToolbox header files, a talk from WWDC 2014 and
-// experimentation.
+// Copies characters from a CFStringRef into a std::string.
+std::string CFStringToString(const CFStringRef cf_string);
 
-namespace webrtc {
+// Convenience function for setting a VT property.
+void SetVTSessionProperty(VTSessionRef session, CFStringRef key, int32_t value);
 
-class H264VideoToolboxDecoder : public H264Decoder {
- public:
-  H264VideoToolboxDecoder();
+// Convenience function for setting a VT property.
+void SetVTSessionProperty(VTSessionRef session,
+                          CFStringRef key,
+                          uint32_t value);
 
-  ~H264VideoToolboxDecoder() override;
+// Convenience function for setting a VT property.
+void SetVTSessionProperty(VTSessionRef session, CFStringRef key, bool value);
 
-  int InitDecode(const VideoCodec* video_codec, int number_of_cores) override;
+// Convenience function for setting a VT property.
+void SetVTSessionProperty(VTSessionRef session,
+                          CFStringRef key,
+                          CFStringRef value);
 
-  int Decode(const EncodedImage& input_image,
-             bool missing_frames,
-             const RTPFragmentationHeader* fragmentation,
-             const CodecSpecificInfo* codec_specific_info,
-             int64_t render_time_ms) override;
-
-  int RegisterDecodeCompleteCallback(DecodedImageCallback* callback) override;
-
-  int Release() override;
-
-  const char* ImplementationName() const override;
-
- private:
-  int ResetDecompressionSession();
-  void ConfigureDecompressionSession();
-  void DestroyDecompressionSession();
-  void SetVideoFormat(CMVideoFormatDescriptionRef video_format);
-
-  DecodedImageCallback* callback_;
-  CMVideoFormatDescriptionRef video_format_;
-  VTDecompressionSessionRef decompression_session_;
-};  // H264VideoToolboxDecoder
-
-}  // namespace webrtc
-
-#endif  // WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_VIDEOTOOLBOX_DECODER_H_
+#endif  // WEBRTC_SDK_OBJC_FRAMEWORK_CLASSES_VIDEOTOOLBOX_HELPERS_H_