Add new video codec factories

webrtc/api/video_codecs/video_encoder_factory.h

+/*
+ *  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_API_VIDEO_CODECS_VIDEO_ENCODER_FACTORY_H_
+#define WEBRTC_API_VIDEO_CODECS_VIDEO_ENCODER_FACTORY_H_
+
+#include <memory>
+#include <vector>
+
+namespace webrtc {
+
+class VideoEncoder;
+struct SdpVideoFormat;
+
+// A factory that creates VideoEncoders.
+// NOTE: This class is still under development and may change without notice.
+class VideoEncoderFactory {
+ public:
+  // TODO(magjed): Try to get rid of this struct.
+  struct CodecInfo {
+    // |is_hardware_accelerated| is true if the encoders created by this factory
+    // of the given codec will use hardware support.
+    bool is_hardware_accelerated;
+    // |has_internal_source| is true if encoders created by this factory of the
+    // given codec will use internal camera sources, meaning that they don't
+    // require/expect frames to be delivered via webrtc::VideoEncoder::Encode.
+    // This flag is used as the internal_source parameter to
+    // webrtc::ViEExternalCodec::RegisterExternalSendCodec.
+    bool has_internal_source;
+  };
+
+  // Returns a list of supported video formats in order of preference, to use
+  // for signaling etc.
+  virtual std::vector<SdpVideoFormat> GetSupportedFormats() const = 0;
+
+  // Returns information about how this format will be encoded. The specified
+  // format must be one of the supported formats by this factory.
+  // TODO(magjed): Try to get rid of this method.
+  virtual CodecInfo QueryVideoEncoder(const SdpVideoFormat& format) const = 0;
+
+  // Creates a VideoEncoder for the specified format.
+  virtual std::unique_ptr<VideoEncoder> CreateVideoEncoder(
+      const SdpVideoFormat& format) = 0;
+
+  virtual ~VideoEncoderFactory() {}
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_API_VIDEO_CODECS_VIDEO_ENCODER_FACTORY_H_