欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  移动技术

yuv分量提取(NDK:libyuv)

程序员文章站 2022-09-16 21:09:19
通过ImageReader获得数据来源借助libyuv做转换Image image = mImageReader.acquireLatestImage()图片格式决定了image里面planes有几个数组如下: /** * Only a subset of the formats defined in * {@link android.graphics.ImageFormat ImageFormat} and * {@link android.graphics.P...

通过ImageReader获得数据来源借助libyuv做转换
Image image = mImageReader.acquireLatestImage()
图片格式决定了image里面planes有几个数组
如下:

    /**
     * Only a subset of the formats defined in
     * {@link android.graphics.ImageFormat ImageFormat} and
     * {@link android.graphics.PixelFormat PixelFormat} are supported by
     * ImageReader. When reading RGB data from a surface, the formats defined in
     * {@link android.graphics.PixelFormat PixelFormat} can be used; when
     * reading YUV, JPEG, HEIC or raw sensor data (for example, from the camera
     * or video decoder), formats from {@link android.graphics.ImageFormat ImageFormat}
     * are used.
     */
    public static int getNumPlanesForFormat(int format) {
        switch (format) {
            case ImageFormat.YV12:
            case ImageFormat.YUV_420_888:
            case ImageFormat.NV21:
                return 3;
            case ImageFormat.NV16:
                return 2;
            case PixelFormat.RGB_565:
            case PixelFormat.RGBA_8888:
            case PixelFormat.RGBX_8888:
            case PixelFormat.RGB_888:
            case ImageFormat.JPEG:
            case ImageFormat.YUY2:
            case ImageFormat.Y8:
            case ImageFormat.Y16:
            case ImageFormat.RAW_SENSOR:
            case ImageFormat.RAW_PRIVATE:
            case ImageFormat.RAW10:
            case ImageFormat.RAW12:
            case ImageFormat.DEPTH16:
            case ImageFormat.DEPTH_POINT_CLOUD:
            case ImageFormat.RAW_DEPTH:
            case ImageFormat.DEPTH_JPEG:
            case ImageFormat.HEIC:
                return 1;
            case ImageFormat.PRIVATE:
                return 0;
            default:
                throw new UnsupportedOperationException(
                        String.format("Invalid format specified %d", format));
        }
    }

以上为ImageUtility里面给出的线索,故从此之后再也不愁应该在image的planes里面取几组数据了。

RGBA_8888

如上,只需要取planes[0]就好。

if (image.getFormat() == PixelFormat.RGBA_8888) {
    ByteBuffer byteBuffer = image.getPlanes()[0].getBuffer();
    byte[] bytes = new byte[byteBuffer.limit()];
    byteBuffer.get(bytes);
    enCodeSource(bytes, image.getWidth(), image.getHeight(), bytes.length);
    return super.loop();
}

//native
public native void enCodeSource(byte[] buffer, int width, int height, int size);

native层

extern "C"
JNIEXPORT void JNICALL
Java_com_freeme_cloudmirror_daemon_VideoServer3_enCodeSource(JNIEnv *env, jobject thiz,
                                                             jbyteArray buffer, jint width,
                                                             jint height, jint size) {
    uint8_t *rgbBuffer = (unsigned char *) env->GetByteArrayElements(buffer, NULL);
    int y_length = width * height;
    int u_length = (width * height) / 4;
    int v_length = u_length;
    uint8_t *y = (unsigned char *) malloc(y_length);
    uint8_t *u = (unsigned char *) malloc(u_length);
    uint8_t *v = (unsigned char *) malloc(v_length);
    LOGE("y:%d \r u:%d \r v:%d \r size:%d",y_length,u_length,v_length,size);
    libyuv::ARGBToI420(rgbBuffer, width * 4, y, width, u, (width + 1) / 2, v,
                       (width + 1) / 2, width, height);
}

参数记录

/**
ARGB little endian (bgra in memory) to I420.
		src_argb:用于待转换的argb数据。
		src_stride_argb:argb数据每一行的大小,如果是argb_8888格式的话这个值为 width * 4,argb4444的话值为 width * 2。
		dst_y:用于保存y分量数据。
		dst_stride_y:值为 width * height。
		dst_u:用于保存u分量数据。
		dst_stride_u:值为(width+1)/2。
		dst_v:用于保存分量数据。
		dst_stride_v:值为(width+1)/2。
		width:位图宽度。
		height:位图高度。
*/
LIBYUV_API
int ARGBToI420(const uint8* src_frame, int src_stride_frame,
               uint8* dst_y, int dst_stride_y,
               uint8* dst_u, int dst_stride_u,
               uint8* dst_v, int dst_stride_v,
               int width, int height);

YUV_420_888

     final Image.Plane[] planes = image.getPlanes();

     int width = image.getWidth();
     int height = image.getHeight();

     byte[] yBytes = new byte[width * height];//y分量
     int dstIndex = 0;

     byte uBytes[] = new byte[width * height / 4];//u分量
     byte vBytes[] = new byte[width * height / 4];//v分量
     int uIndex = 0;
     int vIndex = 0;

     int pixelsStride, rowStride;
     for (int i = 0; i < planes.length; i++) {
         pixelsStride = planes[i].getPixelStride();
         rowStride = planes[i].getRowStride();

         ByteBuffer buffer = planes[i].getBuffer();

         byte[] bytes = new byte[buffer.capacity()];
         buffer.get(bytes);

         int srcIndex = 0;
         if (i == 0) {
             for (int j = 0; j < height; j++) {
                 System.arraycopy(bytes, srcIndex, yBytes, dstIndex, width);
                 srcIndex += rowStride;
                 dstIndex += width;
             }
         } else if (i == 1) {
             for (int j = 0; j < height / 2; j++) {
                 for (int k = 0; k < width / 2; k++) {
                     uBytes[uIndex++] = bytes[srcIndex];
                     srcIndex += pixelsStride;
                 }
                 if (pixelsStride == 2) {
                     srcIndex += rowStride - width;
                 } else if (pixelsStride == 1) {
                     srcIndex += rowStride - width / 2;
                 }
             }
         } else if (i == 2) {
             for (int j = 0; j < height / 2; j++) {
                 for (int k = 0; k < width / 2; k++) {
                     vBytes[vIndex++] = bytes[srcIndex];
                     srcIndex += pixelsStride;
                 }
                 if (pixelsStride == 2) {
                     srcIndex += rowStride - width;
                 } else if (pixelsStride == 1) {
                     srcIndex += rowStride - width / 2;
                 }
             }
         }
     }

本文地址:https://blog.csdn.net/qq_33717425/article/details/107180621