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/*
* 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 MEDIA_BASE_VIDEOADAPTER_H_
#define MEDIA_BASE_VIDEOADAPTER_H_
#include <utility>
#include "absl/types/optional.h"
#include "media/base/videocommon.h"
#include "rtc_base/constructormagic.h"
#include "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);
// DEPRECATED. Please use OnOutputFormatRequest below.
// TODO(asapersson): Remove this once it is no longer used.
// 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.
// Note: Should be called from the source only.
void OnOutputFormatRequest(const absl::optional<VideoFormat>& format);
// Requests output frame size and frame interval from |AdaptFrameResolution|.
// |target_aspect_ratio|: The input frame size will be cropped to match the
// requested aspect ratio. The aspect ratio is orientation agnostic and will
// be adjusted to maintain the input orientation (i.e. it doesn't matter if
// e.g. <1280,720> or <720,1280> is requested).
// |max_pixel_count|: The maximum output frame size.
// |max_fps|: The maximum output framerate.
// Note: Should be called from the source only.
void OnOutputFormatRequest(
const absl::optional<std::pair<int, int>>& target_aspect_ratio,
const absl::optional<int>& max_pixel_count,
const absl::optional<int>& max_fps);
// 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.
// Note: Should be called from the sink only.
void OnResolutionFramerateRequest(
const absl::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.
absl::optional<int64_t> next_frame_timestamp_ns_
RTC_GUARDED_BY(critical_section_);
// Max number of pixels/fps requested via calls to OnOutputFormatRequest,
// OnResolutionFramerateRequest respectively.
// The adapted output format is the minimum of these.
absl::optional<std::pair<int, int>> target_aspect_ratio_
RTC_GUARDED_BY(critical_section_);
absl::optional<int> max_pixel_count_ RTC_GUARDED_BY(critical_section_);
absl::optional<int> max_fps_ 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 // MEDIA_BASE_VIDEOADAPTER_H_