1、大作業(yè)1題目如下：開發(fā)DVPP應(yīng)用，輸入，輸出都是JPEG圖片，且分辨率不同。

根據(jù)作業(yè)提示，轉(zhuǎn)換的思路如下：
原始JPEG圖片->JPEG解碼->YUV Resize->JPEGE->保存JPEG圖片
這些應(yīng)該使用dvpp技術(shù)，在device端進(jìn)行轉(zhuǎn)換。其流程應(yīng)滿足dvpp的流程設(shè)計(jì)和編碼方式。
下面看看如何實(shí)戰(zhàn)。
實(shí)現(xiàn)JPEG圖片解碼-縮放-編碼的過程應(yīng)該使用dvpp技術(shù)，在device端進(jìn)行轉(zhuǎn)換，其流程滿足dvpp的流程設(shè)計(jì)和編碼方式

2、sample參考

根據(jù)學(xué)習(xí)的內(nèi)容，原來的sample倉里面，包含三個(gè)JPEGD、VPC Resize、JPEGE單獨(dú)的樣例：

2.1 JPEGD 解碼

輸入JPEG圖片，解碼為YUV420格式，保存為yuv格式的文件，sample運(yùn)行截圖：

2.2 VPC Resize

輸入YUV圖片，根據(jù)Resize的尺寸，保存resize之后的YUV圖片，sample運(yùn)行截圖：

2.3 JPEGE 編碼

輸入yuv圖片，調(diào)用編碼接口，保存JPEG圖片，sample運(yùn)行截圖：

3、JPEGD + VPC Resize + JPEGE串聯(lián)

根據(jù)學(xué)習(xí)的內(nèi)容，按照以下思路將完整的功能串聯(lián)在一起輸出代碼，實(shí)現(xiàn)內(nèi)存的復(fù)用，JPEGD解碼后的YUV輸出內(nèi)存給到VPC Resize，Resize之后的內(nèi)存給到JPEGE，編碼之后根據(jù)內(nèi)存輸出地址和Buffersize，寫文件圖片即可。
下面廢話不多說，直接上關(guān)鍵實(shí)現(xiàn)代碼，完整代碼請(qǐng)看作業(yè)貼回復(fù)附件。

3.1.JPEG圖片解碼

主要接口：
acldvppJpegDecodeAsync異步接口進(jìn)行解碼
代碼實(shí)現(xiàn)：

//##執(zhí)行異步解碼 ret = acldvppJpegDecodeAsync(dvppChannelDesc_, inDevBuffer_, inDevBufferSize_, decodeOutputDesc_, stream_); if (ret != ACL_SUCCESS) {ERROR_LOG("acldvppJpegDecodeAsync failed, ret = %d", ret);return FAILED; }ret = aclrtSynchronizeStream(stream_); if (ret != ACL_SUCCESS) {ERROR_LOG("aclrtSynchronizeStream failed");return FAILED; }

3.2. VPC Resize

acldvppCreateResizeConfig縮放配置接口
acldvppVpcResizeAsync異步接口，將輸入圖片縮放到輸出圖片大小,輸出大小這里設(shè)置為640*480，可以自行修改。
代碼實(shí)現(xiàn)：

acldvppResizeConfig *resizeConfig_ = acldvppCreateResizeConfig(); uint32_t modelInputWidth = 640; uint32_t modelInputHeight = 480; uint32_t sizeAlignment = 3; uint32_t sizeNum = 2;acldvppPicDesc *vpcOutputDesc_ = acldvppCreatePicDesc(); void *vpcOutBufferDev_ = nullptr;acldvppSetPicDescData(vpcOutputDesc_, vpcOutBufferDev_);acldvppSetPicDescFormat(vpcOutputDesc_, PIXEL_FORMAT_YUV_SEMIPLANAR_420); acldvppSetPicDescWidth(vpcOutputDesc_, modelInputWidth); acldvppSetPicDescHeight(vpcOutputDesc_, modelInputHeight); acldvppSetPicDescWidthStride(vpcOutputDesc_, resizeOutWidthStride); acldvppSetPicDescHeightStride(vpcOutputDesc_, resizeOutHeightStride); acldvppSetPicDescSize(vpcOutputDesc_, vpcOutBufferSize_);ret = acldvppVpcResizeAsync(dvppChannelDesc_, decodeOutputDesc_, vpcOutputDesc_, resizeConfig_, stream_);

3.3. JPEGE編碼

主要接口：
acldvppCreateJpegeConfig創(chuàng)建圖片編碼配置數(shù)據(jù)
acldvppJpegEncodeAsync異步編碼
代碼實(shí)現(xiàn)：

uint32_t encodeLevel = 100; // default optimal level (0-100) acldvppJpegeConfig *jpegeConfig_; void* encode_out_buffer_dev_; jpegeConfig_ = acldvppCreateJpegeConfig();//call Asynchronous api aclRet = acldvppJpegEncodeAsync(dvppChannelDesc_, vpcOutputDesc_, encode_out_buffer_dev_, &encode_outbuffer_size_, jpegeConfig_, stream_);

3.4. 保存JPEG圖片

根據(jù)編碼輸出內(nèi)存地址和Buffersize，寫入到JPEG圖片：

int dir_tail_index = image_path.find("/data");std::string outfile_dir = image_path.substr(0, dir_tail_index) + "/" + "out/output/";std::string outfile_path = outfile_dir + image_path.substr(dir_tail_index+5+1, image_path.rfind(".jpg")-dir_tail_index-5-1) + "_jpege_" + std::to_string(modelInputWidth) + "_" + std::to_string(modelInputHeight) + ".jpg"; INFO_LOG("outfile_path=%s", outfile_path.c_str());ret = save_dvpp_outputdata(outfile_path.c_str(), encode_out_buffer_dev_, encode_outbuffer_size_);if (ret != SUCCESS) {ERROR_LOG("save dvpp output data failed");// allow not return}

3.5. 運(yùn)行效果

編譯：

cd jpegd_resize_jpede/ cd scripts/ bash sample_build.sh

編譯Log：

bash sample_build.sh ../../../../../common [INFO] Sample preparation please input TargetKernel? [arm/x86]:x86 [INFO] input is normal, start preparation. -- The C compiler identification is GNU 7.5.0 -- The CXX compiler identification is GNU 7.5.0 -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Check for working C compiler: /usr/bin/cc - skipped -- Detecting C compile features -- Detecting C compile features - done -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Check for working CXX compiler: /usr/bin/g++ - skipped -- Detecting CXX compile features -- Detecting CXX compile features - done -- Configuring done -- Generating done -- Build files have been written to: /home/gitee/samples/cplusplus/level2_simple_inference/0_data_process/jpegd_resize_jpede/build/intermediates/host Scanning dependencies of target main [ 50%] Building CXX object CMakeFiles/main.dir/main.cpp.o [100%] Linking CXX executable /home/gitee/samples/cplusplus/level2_simple_inference/0_data_process/jpegd_resize_jpede/out/main

運(yùn)行：

bash sample_run.sh

運(yùn)行Log：

[INFO] The sample starts to run [INFO] acl init success [INFO] open device 0 success [INFO] create stream success [INFO] start to process picture:../data/dog1_1024_683.jpg [INFO] get jpeg image info successed, width=1024, height=683, format=2, jpegDecodeSize=0 [INFO] dvpp init resource success [INFO] VPC Resized_Width=640, Resized_Hight=480, Output_Buffer_Size=460800 [INFO] Call acldvppCreateJpegeConfig success [INFO] Call acldvppJpegEncodeAsync success [INFO] outfile_path=../out/output/dog1_1024_683_jpege_640_480.jpg [INFO] end to destroy stream [INFO] end to destroy context [INFO] end to reset device is 0 [INFO] end to finalize acl [INFO] execute sample success [INFO] The program runs successfully, please view the result file in the /home/gitee/samples/cplusplus/level2_simple_inference/0_data_process/jpegd_resize_jpede/scripts/../out/output directory!

輸出Resize之后的圖片：

完美符合預(yù)期！！！

總結(jié)

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