[Android] Add PP-OCRv3 int8 docs and fix NULL cls result error (#762)

* [Android] Update ppseg jni via new api and optimize jni vis funcs

* delete local refs

* [Android] Add PPTinyPose jni and java api

* [Android] Update gradle download tasks info

* [Android] Add PPTinyPose Android app example

* update app build.gradle

* [Android] Add PP-OCRv3 int8 docs and fix NULL cls result error

examples/vision/ocr/PP-OCRv3/android/README.md

@@ -79,6 +79,26 @@ public boolean initialized(); // 检查是否初始化成功
 <string name="OCR_MODEL_DIR_DEFAULT">models</string>  
 <string name="OCR_LABEL_PATH_DEFAULT">labels/ppocr_keys_v1.txt</string>
 ```  
+## 使用量化模型  
+如果您使用的是量化格式的模型，只需要使用RuntimeOption的enableLiteInt8()接口设置Int8精度推理即可。
+```java
+String detModelFile = "ch_ppocrv3_plate_det_quant/inference.pdmodel";
+String detParamsFile = "ch_ppocrv3_plate_det_quant/inference.pdiparams";
+String recModelFile = "ch_ppocrv3_plate_rec_distillation_quant/inference.pdmodel";
+String recParamsFile = "ch_ppocrv3_plate_rec_distillation_quant/inference.pdiparams";
+String recLabelFilePath = "ppocr_keys_v1.txt"; // ppocr_keys_v1.txt
+RuntimeOption detOption = new RuntimeOption();
+RuntimeOption recOption = new RuntimeOption();
+// 使用Int8精度进行推理
+detOption.enableLiteInt8();
+recOption.enableLiteInt8();
+// 初始化PP-OCRv3 Pipeline
+PPOCRv3 predictor = new PPOCRv3();
+DBDetector detModel = new DBDetector(detModelFile, detParamsFile, detOption);
+Recognizer recModel = new Recognizer(recModelFile, recParamsFile, recLabelFilePath, recOption);
+predictor.init(detModel, recModel);
+```
+在App中使用，可以参考 [OcrMainActivity.java](./app/src/main/java/com/baidu/paddle/fastdeploy/app/examples/ocr/OcrMainActivity.java) 中的用法。  
 
 ## 更多参考文档
 如果您想知道更多的FastDeploy Java API文档以及如何通过JNI来接入FastDeploy C++ API感兴趣，可以参考以下内容:

java/android/app/src/main/AndroidManifest.xml

@@ -15,14 +15,14 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-        <activity android:name=".keypointdetection.KeyPointDetectionMainActivity">
+        <activity android:name=".ocr.OcrMainActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
                 <category android:name="android.intent.category.LAUNCHER"/>
             </intent-filter>
         </activity>
         <activity
-            android:name=".keypointdetection.KeyPointDetectionSettingsActivity"
+            android:name=".ocr.OcrSettingsActivity"
             android:label="Settings">
         </activity>
     </application>

java/android/app/src/main/java/com/baidu/paddle/fastdeploy/app/examples/ocr/OcrMainActivity.java

@@ -31,6 +31,7 @@ import android.widget.TextView;
 import com.baidu.paddle.fastdeploy.RuntimeOption;
 import com.baidu.paddle.fastdeploy.app.examples.R;
 import com.baidu.paddle.fastdeploy.pipeline.PPOCRv2;
+import com.baidu.paddle.fastdeploy.pipeline.PPOCRv3;
 import com.baidu.paddle.fastdeploy.ui.Utils;
 import com.baidu.paddle.fastdeploy.ui.view.CameraSurfaceView;
 import com.baidu.paddle.fastdeploy.ui.view.ResultListView;
@@ -41,6 +42,7 @@ import com.baidu.paddle.fastdeploy.vision.Visualize;
 import com.baidu.paddle.fastdeploy.vision.ocr.Classifier;
 import com.baidu.paddle.fastdeploy.vision.ocr.DBDetector;
 import com.baidu.paddle.fastdeploy.vision.ocr.Recognizer;
+
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
@@ -423,9 +425,7 @@ public class OcrMainActivity extends Activity implements View.OnClickListener, C
         if (OcrSettingsActivity.checkAndUpdateSettings(this)) {
             String realModelDir = getCacheDir() + "/" + OcrSettingsActivity.modelDir;
             String detModelName = "ch_PP-OCRv2_det_infer";
-            // String detModelName = "ch_ppocr_mobile_v2.0_det_infer";
             String clsModelName = "ch_ppocr_mobile_v2.0_cls_infer";
-            // String recModelName = "ch_ppocr_mobile_v2.0_rec_infer";
             String recModelName = "ch_PP-OCRv2_rec_infer";
             String realDetModelDir = realModelDir + "/" + detModelName;
             String realClsModelDir = realModelDir + "/" + clsModelName;
@@ -460,11 +460,11 @@ public class OcrMainActivity extends Activity implements View.OnClickListener, C
                 clsOption.enableLiteFp16();
                 recOption.enableLiteFp16();
             }
+
             DBDetector detModel = new DBDetector(detModelFile, detParamsFile, detOption);
             Classifier clsModel = new Classifier(clsModelFile, clsParamsFile, clsOption);
             Recognizer recModel = new Recognizer(recModelFile, recParamsFile, recLabelFilePath, recOption);
             predictor.init(detModel, clsModel, recModel);
-
         }
     }
 

java/android/fastdeploy/src/main/cpp/fastdeploy_jni/vision/results_jni.cc

@@ -842,9 +842,12 @@ bool AllocateOCRResultFromJava(
     return false;
   }
 
-  const int cls_len = env->GetArrayLength(j_ocr_cls_scores_float_arr);
+  int cls_len = 0;
-  if (cls_len != env->GetArrayLength(j_ocr_cls_labels_int_arr)) {
+  if ((j_ocr_cls_labels_int_arr != NULL) && (j_ocr_cls_scores_float_arr != NULL)) {
-    return false;
+    cls_len = env->GetArrayLength(j_ocr_cls_scores_float_arr);
+    if (cls_len != env->GetArrayLength(j_ocr_cls_labels_int_arr)) {
+      return false;
+    }
   }
 
   // Init cxx result