| /* |
| * Copyright (c) 2010 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_MEDIA_BASE_VIDEOADAPTER_H_ |
| #define WEBRTC_MEDIA_BASE_VIDEOADAPTER_H_ |
| |
| #include "webrtc/api/optional.h" |
| #include "webrtc/media/base/videocommon.h" |
| #include "webrtc/rtc_base/constructormagic.h" |
| #include "webrtc/rtc_base/criticalsection.h" |
| |
| namespace cricket { |
| |
| // VideoAdapter adapts an input video frame to an output frame based on the |
| // specified input and output formats. The adaptation includes dropping frames |
| // to reduce frame rate and scaling frames. |
| // VideoAdapter is thread safe. |
| class VideoAdapter { |
| public: |
| VideoAdapter(); |
| // The output frames will have height and width that is divisible by |
| // |required_resolution_alignment|. |
| explicit VideoAdapter(int required_resolution_alignment); |
| virtual ~VideoAdapter(); |
| |
| // Return the adapted resolution and cropping parameters given the |
| // input resolution. The input frame should first be cropped, then |
| // scaled to the final output resolution. Returns true if the frame |
| // should be adapted, and false if it should be dropped. |
| bool AdaptFrameResolution(int in_width, |
| int in_height, |
| int64_t in_timestamp_ns, |
| int* cropped_width, |
| int* cropped_height, |
| int* out_width, |
| int* out_height); |
| |
| // Requests the output frame size and frame interval from |
| // |AdaptFrameResolution| to not be larger than |format|. Also, the input |
| // frame size will be cropped to match the requested aspect ratio. The |
| // requested aspect ratio is orientation agnostic and will be adjusted to |
| // maintain the input orientation, so it doesn't matter if e.g. 1280x720 or |
| // 720x1280 is requested. |
| void OnOutputFormatRequest(const VideoFormat& format); |
| |
| // Requests the output frame size from |AdaptFrameResolution| to have as close |
| // as possible to |target_pixel_count| pixels (if set) but no more than |
| // |max_pixel_count|. |
| // |max_framerate_fps| is essentially analogous to |max_pixel_count|, but for |
| // framerate rather than resolution. |
| // Set |max_pixel_count| and/or |max_framerate_fps| to |
| // std::numeric_limit<int>::max() if no upper limit is desired. |
| void OnResolutionFramerateRequest( |
| const rtc::Optional<int>& target_pixel_count, |
| int max_pixel_count, |
| int max_framerate_fps); |
| |
| private: |
| // Determine if frame should be dropped based on input fps and requested fps. |
| bool KeepFrame(int64_t in_timestamp_ns); |
| |
| int frames_in_; // Number of input frames. |
| int frames_out_; // Number of output frames. |
| int frames_scaled_; // Number of frames scaled. |
| int adaption_changes_; // Number of changes in scale factor. |
| int previous_width_; // Previous adapter output width. |
| int previous_height_; // Previous adapter output height. |
| // Resolution must be divisible by this factor. |
| const int required_resolution_alignment_; |
| // The target timestamp for the next frame based on requested format. |
| rtc::Optional<int64_t> next_frame_timestamp_ns_ |
| RTC_GUARDED_BY(critical_section_); |
| |
| // Max number of pixels requested via calls to OnOutputFormatRequest, |
| // OnResolutionRequest respectively. |
| // The adapted output format is the minimum of these. |
| rtc::Optional<VideoFormat> requested_format_ |
| RTC_GUARDED_BY(critical_section_); |
| int resolution_request_target_pixel_count_ RTC_GUARDED_BY(critical_section_); |
| int resolution_request_max_pixel_count_ RTC_GUARDED_BY(critical_section_); |
| int max_framerate_request_ RTC_GUARDED_BY(critical_section_); |
| |
| // The critical section to protect the above variables. |
| rtc::CriticalSection critical_section_; |
| |
| RTC_DISALLOW_COPY_AND_ASSIGN(VideoAdapter); |
| }; |
| |
| } // namespace cricket |
| |
| #endif // WEBRTC_MEDIA_BASE_VIDEOADAPTER_H_ |