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/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// VideoSourceDownSampler implements the MediaSource interface,
// downsampling frames provided from a real video source.
#ifndef VIDEO_SOURCE_DOWN_SAMPLER_H_
#define VIDEO_SOURCE_DOWN_SAMPLER_H_
#include <media/stagefright/MediaSource.h>
#include <utils/RefBase.h>
namespace android {
class IMemory;
class MediaBuffer;
class MetaData;
class VideoSourceDownSampler : public MediaSource {
public:
virtual ~VideoSourceDownSampler();
// Constructor:
// videoSource: The real video source which provides the original frames.
// width, height: The desired width, height. These should be less than or equal
// to those of the real video source. We then downsample the original frames to
// this size.
VideoSourceDownSampler(const sp<MediaSource> &videoSource,
int32_t width, int32_t height);
// MediaSource interface
virtual status_t start(MetaData *params = NULL);
virtual status_t stop();
virtual sp<MetaData> getFormat();
virtual status_t read(
MediaBuffer **buffer, const ReadOptions *options = NULL);
virtual status_t pause();
private:
// Reference to the real video source.
sp<MediaSource> mRealVideoSource;
// Size of frames to be provided by this source.
int32_t mWidth;
int32_t mHeight;
// Size of frames provided by the real source.
int32_t mRealSourceWidth;
int32_t mRealSourceHeight;
// Down sampling paramters.
int32_t mDownSampleOffsetX;
int32_t mDownSampleOffsetY;
int32_t mDownSampleSkipX;
int32_t mDownSampleSkipY;
// True if we need to crop the still video image to get the video frame.
bool mNeedDownSampling;
// Meta data. This is a copy of the real source except for the width and
// height parameters.
sp<MetaData> mMeta;
// Computes the offset, skip parameters for downsampling the original frame
// to the desired size.
void computeDownSamplingParameters();
// Downsamples the frame in sourceBuffer to size (mWidth x mHeight). A new
// buffer is created which stores the downsampled image.
void downSampleYUVImage(const MediaBuffer &sourceBuffer, MediaBuffer **buffer) const;
// Disallow these.
VideoSourceDownSampler(const VideoSourceDownSampler &);
VideoSourceDownSampler &operator=(const VideoSourceDownSampler &);
};
} // namespace android
#endif // VIDEO_SOURCE_DOWN_SAMPLER_H_
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