1 /* 2 * Copyright (c) 2010 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef MEDIA_BASE_VIDEO_ADAPTER_H_ 12 #define MEDIA_BASE_VIDEO_ADAPTER_H_ 13 14 #include <stdint.h> 15 16 #include <utility> 17 18 #include "absl/types/optional.h" 19 #include "api/video/video_source_interface.h" 20 #include "media/base/video_common.h" 21 #include "rtc_base/constructor_magic.h" 22 #include "rtc_base/synchronization/mutex.h" 23 #include "rtc_base/thread_annotations.h" 24 25 namespace cricket { 26 27 // VideoAdapter adapts an input video frame to an output frame based on the 28 // specified input and output formats. The adaptation includes dropping frames 29 // to reduce frame rate and scaling frames. 30 // VideoAdapter is thread safe. 31 class VideoAdapter { 32 public: 33 VideoAdapter(); 34 // The source requests output frames whose width and height are divisible 35 // by |source_resolution_alignment|. 36 explicit VideoAdapter(int source_resolution_alignment); 37 virtual ~VideoAdapter(); 38 39 // Return the adapted resolution and cropping parameters given the 40 // input resolution. The input frame should first be cropped, then 41 // scaled to the final output resolution. Returns true if the frame 42 // should be adapted, and false if it should be dropped. 43 bool AdaptFrameResolution(int in_width, 44 int in_height, 45 int64_t in_timestamp_ns, 46 int* cropped_width, 47 int* cropped_height, 48 int* out_width, 49 int* out_height) RTC_LOCKS_EXCLUDED(mutex_); 50 51 // DEPRECATED. Please use OnOutputFormatRequest below. 52 // TODO(asapersson): Remove this once it is no longer used. 53 // Requests the output frame size and frame interval from 54 // |AdaptFrameResolution| to not be larger than |format|. Also, the input 55 // frame size will be cropped to match the requested aspect ratio. The 56 // requested aspect ratio is orientation agnostic and will be adjusted to 57 // maintain the input orientation, so it doesn't matter if e.g. 1280x720 or 58 // 720x1280 is requested. 59 // Note: Should be called from the source only. 60 void OnOutputFormatRequest(const absl::optional<VideoFormat>& format) 61 RTC_LOCKS_EXCLUDED(mutex_); 62 63 // Requests output frame size and frame interval from |AdaptFrameResolution|. 64 // |target_aspect_ratio|: The input frame size will be cropped to match the 65 // requested aspect ratio. The aspect ratio is orientation agnostic and will 66 // be adjusted to maintain the input orientation (i.e. it doesn't matter if 67 // e.g. <1280,720> or <720,1280> is requested). 68 // |max_pixel_count|: The maximum output frame size. 69 // |max_fps|: The maximum output framerate. 70 // Note: Should be called from the source only. 71 void OnOutputFormatRequest( 72 const absl::optional<std::pair<int, int>>& target_aspect_ratio, 73 const absl::optional<int>& max_pixel_count, 74 const absl::optional<int>& max_fps) RTC_LOCKS_EXCLUDED(mutex_); 75 76 // Same as above, but allows setting two different target aspect ratios 77 // depending on incoming frame orientation. This gives more fine-grained 78 // control and can e.g. be used to force landscape video to be cropped to 79 // portrait video. 80 void OnOutputFormatRequest( 81 const absl::optional<std::pair<int, int>>& target_landscape_aspect_ratio, 82 const absl::optional<int>& max_landscape_pixel_count, 83 const absl::optional<std::pair<int, int>>& target_portrait_aspect_ratio, 84 const absl::optional<int>& max_portrait_pixel_count, 85 const absl::optional<int>& max_fps) RTC_LOCKS_EXCLUDED(mutex_); 86 87 // Requests the output frame size from |AdaptFrameResolution| to have as close 88 // as possible to |sink_wants.target_pixel_count| pixels (if set) 89 // but no more than |sink_wants.max_pixel_count|. 90 // |sink_wants.max_framerate_fps| is essentially analogous to 91 // |sink_wants.max_pixel_count|, but for framerate rather than resolution. 92 // Set |sink_wants.max_pixel_count| and/or |sink_wants.max_framerate_fps| to 93 // std::numeric_limit<int>::max() if no upper limit is desired. 94 // The sink resolution alignment requirement is given by 95 // |sink_wants.resolution_alignment|. 96 // Note: Should be called from the sink only. 97 void OnSinkWants(const rtc::VideoSinkWants& sink_wants) 98 RTC_LOCKS_EXCLUDED(mutex_); 99 100 private: 101 // Determine if frame should be dropped based on input fps and requested fps. 102 bool KeepFrame(int64_t in_timestamp_ns) RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_); 103 104 int frames_in_ RTC_GUARDED_BY(mutex_); // Number of input frames. 105 int frames_out_ RTC_GUARDED_BY(mutex_); // Number of output frames. 106 int frames_scaled_ RTC_GUARDED_BY(mutex_); // Number of frames scaled. 107 int adaption_changes_ 108 RTC_GUARDED_BY(mutex_); // Number of changes in scale factor. 109 int previous_width_ RTC_GUARDED_BY(mutex_); // Previous adapter output width. 110 int previous_height_ 111 RTC_GUARDED_BY(mutex_); // Previous adapter output height. 112 const bool variable_start_scale_factor_; 113 114 // The fixed source resolution alignment requirement. 115 const int source_resolution_alignment_; 116 // The currently applied resolution alignment, as given by the requirements: 117 // - the fixed |source_resolution_alignment_|; and 118 // - the latest |sink_wants.resolution_alignment|. 119 int resolution_alignment_ RTC_GUARDED_BY(mutex_); 120 121 // The target timestamp for the next frame based on requested format. 122 absl::optional<int64_t> next_frame_timestamp_ns_ RTC_GUARDED_BY(mutex_); 123 124 // Max number of pixels/fps requested via calls to OnOutputFormatRequest, 125 // OnResolutionFramerateRequest respectively. 126 // The adapted output format is the minimum of these. 127 absl::optional<std::pair<int, int>> target_landscape_aspect_ratio_ 128 RTC_GUARDED_BY(mutex_); 129 absl::optional<int> max_landscape_pixel_count_ RTC_GUARDED_BY(mutex_); 130 absl::optional<std::pair<int, int>> target_portrait_aspect_ratio_ 131 RTC_GUARDED_BY(mutex_); 132 absl::optional<int> max_portrait_pixel_count_ RTC_GUARDED_BY(mutex_); 133 absl::optional<int> max_fps_ RTC_GUARDED_BY(mutex_); 134 int resolution_request_target_pixel_count_ RTC_GUARDED_BY(mutex_); 135 int resolution_request_max_pixel_count_ RTC_GUARDED_BY(mutex_); 136 int max_framerate_request_ RTC_GUARDED_BY(mutex_); 137 138 // The critical section to protect the above variables. 139 webrtc::Mutex mutex_; 140 141 RTC_DISALLOW_COPY_AND_ASSIGN(VideoAdapter); 142 }; 143 144 } // namespace cricket 145 146 #endif // MEDIA_BASE_VIDEO_ADAPTER_H_ 147