jni層使用skia解碼jpeg數據流

首發 edn論壇

在網上找不到實例代碼

skia的sample也沒有。只好跟着BitmapFartory.cpp

總結了一下寫出下面代碼。

void init_bitmap(){
    src_bitmap = new SkBitmap;
    stream    = new SkMemoryStream();
    //SkAutoUnref aur(stream);
}

void jpegtoABGRY(unsigned char *src,int length)
{
    
    
    SkBitmap::Config prefConfig = SkBitmap::kARGB_8888_Config;
    SkImageDecoder::Mode mode = SkImageDecoder::kDecodePixels_Mode;;
    bool doDither = false;
    bool isMutable = false,ret;
    stream->setMemory(src,length,false);
    //SkJPEGImageDecoder* decoder = new SkJPEGImageDecoder;
    SkImageDecoder* decoder = SkImageDecoder::Factory(stream);
    if (NULL == decoder) {
        LOGE("SkImageDecoder::Factory returned null");
        return;
    }
    //decoder->setSampleSize(1);
    decoder->setDitherImage(false);
    //decoder->setPreferQualityOverSpeed(false);
    SkImageDecoder::Format format = SkImageDecoder::kJPEG_Format;
    //stream->rewind();
    ret = decoder->decode(stream, src_bitmap, prefConfig, mode, true);
    //SkImageDecoder::DecodeStream(stream, src_bitmap, prefConfig, mode, &format);
    if (!ret) {
    //return android::nullObjectReturn("decoder->decode returned false");
        LOGE("decoder->decode returned false");
        return ;
    }
    //default int dstRowBytes = -1
    DEBUG("here line %d bitmaps: values :%d\t%d",__LINE__,src_bitmap->getSize(),src_bitmap->getConfig());
    src_bitmap->copyPixelsTo(&rgb[0],IMG_WIDTH*IMG_HEIGHT*sizeof(int));
    int fd_tmp,fd_tmp_dst;
#if 0
    if(++counter>5){
        counter = 0;
        DEBUGLOGL();
        fd_tmp = open("/data/tmp.jpg",O_RDWR|O_CREAT|O_TRUNC,777);
        if(fd_tmp<0){
            dbgv(fd_tmp);//strerror (errno)
            goto CONTINUE_FLAG;
        }
        fd_tmp_dst = open("/data/row.rgb",O_RDWR|O_CREAT|O_TRUNC,777);
        if(fd_tmp_dst<0)
            goto CONTINUE_FLAG;
        DEBUGLOGL();
        //write(fd_tmp,src,length);
        write(fd_tmp_dst,&rgb[0],IMG_WIDTH*IMG_HEIGHT*4);
        close(fd_tmp);
        close(fd_tmp_dst);
    }
#endif
CONTINUE_FLAG:    
    delete(decoder);
}

插入到SimpleWebCam工程中就可以使用jpeg輸出的攝像頭了。