目錄

效果展示

關(guān)鍵流程

關(guān)鍵代碼

1.設(shè)置相機(jī)不顯示預(yù)覽

這里由于我們需要處理和顯示的是相機(jī)回調(diào)的數(shù)據(jù)，因此我們并不需要進(jìn)行預(yù)覽，所以我們可以通過Camera的setPreviewTexture方法實現(xiàn)，如下所示

SurfaceTexture surfaceTexture = new SurfaceTexture(GL11Ext.GL_TEXTURE_CROP_RECT_OES);
mCamera.setPreviewTexture(surfaceTexture);

2.處理回調(diào)數(shù)據(jù)

這里的邏輯與我們上面展示的關(guān)鍵流程圖相對應(yīng)，如下所示

cameraHelper.setFrameCallback(new CameraHelper.FrameCallback() {
            @Override
            public void onDecodeFrame(byte[] data,final Camera camera) {
                try {
                    mCanvas=mHolder.lockCanvas();
                    //初始化畫布并在畫布上畫一些東西
                    int width = camera.getParameters().getPreviewSize().width;
                    int height = camera.getParameters().getPreviewSize().height;
                    int[] result = yuv2Rgb(data,width,height);
                    if(matrix == null){
                        matrix = new Matrix();
                        matrix.preScale(mCanvas.getWidth()/1.0f/height,mCanvas.getHeight()/1.0f/width);
                    }
                    Bitmap bitmapTemp = Bitmap.createBitmap(result, height, width, Bitmap.Config.RGB_565);
                    bitmapTemp = Bitmap.createBitmap(bitmapTemp, 0,0,height,width, matrix, false);
                    gpuImage.setImage(bitmapTemp);
                    bitmap = gpuImage.getBitmapWithFilterApplied();
                    mCanvas.drawBitmap(bitmap,0,0,paint);
                    bitmapTemp.recycle();
                }catch (Exception e){
                }finally {
                    //判斷畫布是否為空，從而避免黑屏情況
                    if(mCanvas!=null){
                        mHolder.unlockCanvasAndPost(mCanvas);
                    }
                    camera.addCallbackBuffer(data);
                }
            }
        });

JNI函數(shù)如下

#include <jni.h>
#include <string>
#include <android/bitmap.h>
extern "C"
JNIEXPORT jintArray JNICALL
Java_com_itfitness_filter_MainActivity_yuv2Rgb(JNIEnv *env, jobject thiz,
                                               jbyteArray buf, jint width,
                                               jint height) {
    jbyte *yuv420spSRC = (env)->GetByteArrayElements(buf, 0);
    jbyte *yuv420sp = (jbyte *)malloc(env->GetArrayLength(buf));

    //旋轉(zhuǎn)圖像（因為傳過來的圖像是橫著的）
    int index = 0;
    //旋轉(zhuǎn)Y分量，放入dst數(shù)組
    for (int y = 0; y < width; y++)
        for (int x = 0; x < height; x++) {
            int oldY = (height - 1) - x;
            int oldX = y;
            int oldIndex = oldY * width + oldX;
            yuv420sp[index++] = yuv420spSRC[oldIndex];
        }
    //每四個點采集一組VU分量，共享右上角像素的VU分量
    //根據(jù)Y分量，找到對應(yīng)的VU分量，放入dst數(shù)組
    for (int y = 0; y < width; y += 2)
        for (int x = 0; x < height; x += 2) {
            int oldY = (height - 1) - (x + 1);
            int oldX = y;
            int vuY = height + oldY / 2; //根據(jù)Y分量計算VU分量所在行
            int vuX = oldX;
            int vuIndex = vuY * width + vuX;
            yuv420sp[index++] = yuv420spSRC[vuIndex];
            yuv420sp[index++] = yuv420spSRC[vuIndex + 1];
        }

    //將YUV轉(zhuǎn)為RGB
    int frameSize = width * height;
    jint rgb[frameSize];
    int i = 0, j = 0, yp = 0;
    int uvp = 0, u = 0, v = 0;
    for (j = 0, yp = 0; j < height; j++) {
        uvp = frameSize + (j >> 1) * width;
        u = 0;
        v = 0;
        for (i = 0; i < width; i++, yp++) {
            int y = (0xff & ((int) yuv420sp[yp])) - 16;
            if (y < 0)
                y = 0;
            if ((i & 1) == 0) {
                v = (0xff & yuv420sp[uvp++]) - 128;
                u = (0xff & yuv420sp[uvp++]) - 128;
            }

            int y1192 = 1192 * y;
            int r = (y1192 + 1634 * v);
            int g = (y1192 - 833 * v - 400 * u);
            int b = (y1192 + 2066 * u);

            if (r < 0) r = 0; else if (r > 262143) r = 262143;
            if (g < 0) g = 0; else if (g > 262143) g = 262143;
            if (b < 0) b = 0; else if (b > 262143) b = 262143;

            rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff);
        }
    }
    jintArray result = (env)->NewIntArray(frameSize);
    (env)->SetIntArrayRegion(result, 0, frameSize, rgb);
    free(yuv420sp);
    (env)->ReleaseByteArrayElements(buf, yuv420spSRC, 0);
    return result;
}

另外我通過按鈕的點擊來切換GpuImage的濾鏡

 bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                opera++;
                if(opera > 3){
                    opera = 0;
                }
                switch (opera){
                    case 0:
                        gpuImage.setFilter(new GPUImageDissolveBlendFilter());
                        break;
                    case 1:
                        //素描
                        gpuImage.setFilter(new GPUImageSketchFilter());
                        break;
                    case 2:
                        //水彩
                        gpuImage.setFilter(new GPUImageToonFilter());
                        break;
                    case 3:
                        //二值化
                        gpuImage.setFilter(new GPUImageThresholdEdgeDetection());
                        break;
                }
            }
        });

案例源碼

詳細(xì)的代碼可以下載源碼查看：https://gitee.com/itfitness/camera-filter