C++程序  |  75行  |  2.56 KB

#ifndef _ANDROID_GRAPHICS_YUV_TO_JPEG_ENCODER_H_
#define _ANDROID_GRAPHICS_YUV_TO_JPEG_ENCODER_H_

#include "SkTypes.h"
#include "SkStream.h"
extern "C" {
    #include "jpeglib.h"
    #include "jerror.h"
}

class YuvToJpegEncoder {
public:
    /** Create an encoder based on the YUV format.
     *
     *  @param pixelFormat The yuv pixel format as defined in ui/PixelFormat.h.
     *  @param strides The number of row bytes in each image plane.
     *  @return an encoder based on the pixelFormat.
     */
    static YuvToJpegEncoder* create(int pixelFormat, int* strides);

    YuvToJpegEncoder(int* strides);

    /** Encode YUV data to jpeg,  which is output to a stream.
     *
     *  @param stream The jpeg output stream.
     *  @param inYuv The input yuv data.
     *  @param width Width of the the Yuv data in terms of pixels.
     *  @param height Height of the Yuv data in terms of pixels.
     *  @param offsets The offsets in each image plane with respect to inYuv.
     *  @param jpegQuality Picture quality in [0, 100].
     *  @return true if successfully compressed the stream.
     */
    bool encode(SkWStream* stream,  void* inYuv, int width,
           int height, int* offsets, int jpegQuality);

    virtual ~YuvToJpegEncoder() {}

protected:
    int fNumPlanes;
    int* fStrides;
    void setJpegCompressStruct(jpeg_compress_struct* cinfo, int width,
            int height, int quality);
    virtual void configSamplingFactors(jpeg_compress_struct* cinfo) = 0;
    virtual void compress(jpeg_compress_struct* cinfo,
            uint8_t* yuv, int* offsets) = 0;
};

class Yuv420SpToJpegEncoder : public YuvToJpegEncoder {
public:
    Yuv420SpToJpegEncoder(int* strides);
    virtual ~Yuv420SpToJpegEncoder() {}

private:
    void configSamplingFactors(jpeg_compress_struct* cinfo);
    void deinterleaveYuv(uint8_t* yuv, int width, int height,
            uint8_t*& yPlanar, uint8_t*& uPlanar, uint8_t*& vPlanar);
    void deinterleave(uint8_t* vuPlanar, uint8_t* uRows, uint8_t* vRows,
            int rowIndex, int width, int height);
    void compress(jpeg_compress_struct* cinfo, uint8_t* yuv, int* offsets);
};

class Yuv422IToJpegEncoder : public YuvToJpegEncoder {
public:
    Yuv422IToJpegEncoder(int* strides);
    virtual ~Yuv422IToJpegEncoder() {}

private:
    void configSamplingFactors(jpeg_compress_struct* cinfo);
    void compress(jpeg_compress_struct* cinfo, uint8_t* yuv, int* offsets);
    void deinterleave(uint8_t* yuv, uint8_t* yRows, uint8_t* uRows,
            uint8_t* vRows, int rowIndex, int width, int height);
};

#endif  // _ANDROID_GRAPHICS_YUV_TO_JPEG_ENCODER_H_