编译

首先按照PaddleLite 源码编译准备交叉编译环境,之后拉取最新PaddleLite release发布版代码。下面以Android-ARMv8架构为例,介绍编译过程,并最终在手机上跑通MobilNetv1模型。

进入 Paddle-Lite 目录,运行以下命令编译代码(需加编译选项--build_extra=ON确保完整编译):

./lite/tools/build.sh        \
    --arm_os=android         \
    --arm_abi=armv8          \
    --arm_lang=gcc           \
    --android_stl=c++_static \
    --build_extra=ON         \
    full_publish

编译完成后 ./build.lite.android.armv8.gcc/inference_lite_lib.android.armv8/ 文件夹下包含:

  • cxx
    • include (头文件文件夹)
    • lib (库文件文件夹)
      • libpaddle_api_full_bundled.a
      • libpaddle_api_light_bundled.a
      • libpaddle_light_api_shared.so
      • libpaddle_full_api_shared.so
  • demo
    • cxx (C++ demo)
      • mobile_light (light api demo)
      • mobile_full (full api demo)
      • Makefile.def
      • include
  • third_party (第三方库文件夹)
    • gflags

准备执行环境

执行环境有两种:使用安卓手机;若没安卓手机,也可在安卓模拟器中执行。

环境一:使用安卓手机

将手机连上电脑,在手机上打开选项 -> 开启-开发者模式 -> 开启-USB调试模式。确保 adb devices 能够看到相应的设备。

环境二:使用安卓模拟器

运行下面命令,分别创建安卓armv8、armv7架构的模拟器。若需在真机测试,将模拟器换成相应架构的真机环境即可。

# android-armv8
adb kill-server
adb devices | grep emulator | cut -f1 | while read line; do adb -s $line emu kill; done
echo n | avdmanager create avd -f -n paddle-armv8 -k "system-images;android-24;google_apis;arm64-v8a"
echo -ne '\n' | ${ANDROID_HOME}/emulator/emulator -avd paddle-armv8 -noaudio -no-window -gpu off -port 5554 &
sleep 1m
# android-armv7
adb kill-server
adb devices | grep emulator | cut -f1 | while read line; do adb -s $line emu kill; done
echo n | avdmanager create avd -f -n paddle-armv7 -k "system-images;android-24;google_apis;armeabi-v7a"
echo -ne '\n' | ${ANDROID_HOME}/emulator/emulator -avd paddle-armv7 -noaudio -no-window -gpu off -port 5554 &
sleep 1m

下载模型并运行示例

cd inference_lite_lib.android.armv8/demo/cxx/mobile_full
wget http://paddle-inference-dist.bj.bcebos.com/mobilenet_v1.tar.gz
tar zxvf mobilenet_v1.tar.gz

make

adb push mobilenet_v1 /data/local/tmp/
adb push mobilenetv1_full_api /data/local/tmp/
adb shell chmod +x /data/local/tmp/mobilenetv1_full_api
adb shell "/data/local/tmp/mobilenetv1_full_api --model_dir=/data/local/tmp/mobilenet_v1 --optimized_model_dir=/data/local/tmp/mobilenet_v1.opt"

注:我们也提供了轻量级 API 的 demo,可以执行以下代码运行轻量级 API 示例。

cd ../mobile_light
make
adb push mobilenetv1_light_api /data/local/tmp/
adb shell chmod +x /data/local/tmp/mobilenetv1_light_api
adb shell "/data/local/tmp/mobilenetv1_light_api --model_dir=/data/local/tmp/mobilenet_v1.opt  "

Demo 程序运行结果

Demo 运行成功后 ,将在控制台输出预测结果的前10个类别的预测概率:

Output dim: 1000
Output[0]: 0.000191
Output[100]: 0.000160
Output[200]: 0.000264
Output[300]: 0.000211
Output[400]: 0.001032
Output[500]: 0.000110
Output[600]: 0.004829
Output[700]: 0.001845
Output[800]: 0.000202
Output[900]: 0.000586

如何在代码中使用 API

在C++中使用PaddleLite API非常简单,不需要添加太多额外代码,具体步骤如下:

  • 加入头文件引用
  #include <iostream>
  #include <vector>        
  #include "paddle_api.h"          
  #include "paddle_use_kernels.h"  
  #include "paddle_use_ops.h"      
  #include "paddle_use_passes.h"   
  • 通过MobileConfig设置:模型文件位置(model_dir)、线程数(thread)和能耗模式( power mode )。输入数据(input),从 MobileConfig 创建 PaddlePredictor 并执行预测。 (注:Lite还支持从memory直接加载模型,可以通过MobileConfig::set_model_buffer方法实现)

代码示例:

// 1. Create MobileConfig
MobileConfig config;

// 2. Load model
config.set_model_dir("path to your model directory"); // model dir
/*load model: Lite supports loading model from file or from memory (naive buffer from optimized model)
//Method One: Load model from memory:
void set_model_buffer(const char* model_buffer,
                    size_t model_buffer_size,
                    const char* param_buffer,
                    size_t param_buffer_size)
//Method Two: Load model from file:
void set_model_dir(const std::string& model_dir)  */

// 3. Set MobileConfig (or you can skip this step to use default value):
config.set_power_mode(LITE_POWER_HIGH); // power mode
/*power modes: Lite supports the following power modes
    LITE_POWER_HIGH
    LITE_POWER_LOW
    LITE_POWER_FULL
    LITE_POWER_NO_BIND
    LITE_POWER_RAND_HIGH
    LITE_POWER_RAND_LOW */
config.set_threads("num of threads"); // threads

// 4. Create PaddlePredictor by MobileConfig
std::shared_ptr<PaddlePredictor> predictor =
    CreatePaddlePredictor<MobileConfig>(config);

// 5. Prepare input data
std::unique_ptr<Tensor> input_tensor(std::move(predictor->GetInput(0)));
input_tensor->Resize({1, 3, 224, 224});
auto *data = input_tensor -> mutable_data<float>();
for (int i = 0; i < ShapeProduction(input_tensor->shape()); ++i) {
  data[i] = 1;
}

// 6. Run predictor
predictor->Run();

// 7. Get output
std::unique_ptr<const Tensor> output_tensor(std::move(predictor->GetOutput(0)));

CxxConfig案例: OCR_model的运行

  1. OCR 模型文件:
  2. 示例代码:
#include "paddle_api.h"         // NOLINT
#include "paddle_use_passes.h"  // NOLINT
#include <gflags/gflags.h>
#include <stdio.h>
#include <vector>
using namespace paddle::lite_api; // NOLINT

DEFINE_string(model_dir, "", "Model dir path.");
DEFINE_bool(prefer_int8_kernel, false, "Prefer to run model with int8 kernels");

int64_t ShapeProduction(const shape_t &shape) {
  int64_t res = 1;
  for (auto i : shape)
    res *= i;
  return res;
}

void RunModel() {
  // 1. Set CxxConfig
  CxxConfig config;
  config.set_model_dir(FLAGS_model_dir);
  std::vector<Place> valid_places({Place{TARGET(kARM), PRECISION(kFloat)}});
  if (FLAGS_prefer_int8_kernel) {
    valid_places.insert(valid_places.begin(),
                        Place{TARGET(kARM), PRECISION(kInt8)});
  }
  config.set_valid_places(valid_places);

  // 2. Create PaddlePredictor by CxxConfig
  std::shared_ptr<PaddlePredictor> predictor =
      CreatePaddlePredictor<CxxConfig>(config);

  // 3. Prepare input data
  // input 0
  std::unique_ptr<Tensor> input_tensor(std::move(predictor->GetInput(0)));
  input_tensor->Resize(shape_t({1, 1, 48, 512}));
  auto *data = input_tensor->mutable_data<float>();
  for (int i = 0; i < ShapeProduction(input_tensor->shape()); ++i) {
    data[i] = 1;
  }
  // input1
  std::unique_ptr<Tensor> init_ids(std::move(predictor->GetInput(1)));
  init_ids->Resize(shape_t({1, 1}));
  auto *data_ids = init_ids->mutable_data<float>();
  for (int i = 0; i < ShapeProduction(init_ids->shape()); ++i) {
    data_ids[i] = 0;
  }

  lod_t lod_i;
  lod_i.push_back({0, 1});
  lod_i.push_back({0, 1});
  init_ids->SetLoD(lod_i);
  // input2
  std::unique_ptr<Tensor> init_scores(std::move(predictor->GetInput(2)));
  init_scores->Resize(shape_t({1, 1}));
  auto *data_scores = init_scores->mutable_data<float>();
  for (int i = 0; i < ShapeProduction(init_scores->shape()); ++i) {
    data_scores[i] = 0;
  }
  lod_t lod_s;
  lod_s.push_back({0, 1});
  lod_s.push_back({0, 1});
  init_scores->SetLoD(lod_s);

  // 4. Run predictor
  predictor->Run();

  // 5. Get output
  std::unique_ptr<const Tensor> output_tensor(
      std::move(predictor->GetOutput(0)));
  for (int i = 0; i < ShapeProduction(output_tensor->shape()); i++) {
    printf("Output[%d]: %f\n", i, output_tensor->data<float>()[i]);
  }
}

int main(int argc, char **argv) {
  google::ParseCommandLineFlags(&argc, &argv, true);
  RunModel();
  return 0;
}
  1. 运行方法: 参考以上代码编译出可执行文件OCR_DEMO,模型文件夹为ocr_attention。手机以USB调试、文件传输模式连接电脑。
简单编译出`OCR_DEMO`的方法:用以上示例代码替换编译结果中`build.lite.android.armv8.gcc/inference_lite_lib.android.armv8/demo/cxx/mobile_full/mobilenetv1_full_api.cc`文件的内容,终端进入该路径(`demo/cxx/mobile_full/`),终端中执行`make && mv mobilenetv1_full_api OCR_DEMO`即编译出了OCR模型的可执行文件`OCR_DEMO`

在终端中输入以下命令执行OCR model测试:

#OCR_DEMO为编译出的可执行文件名称,ocr_attention为ocr_attention模型的文件夹名称
adb push OCR_DEMO data/local/tmp
adb push ocr_attention data/local/tmp
adb shell 'cd data/local/tmp && ./OCR_DEMO --model_dir=./OCR_DEMO'
  1. 运行结果