Support for video file instead of camera and output video out to file

webrtc/api/android/jni/peerconnection_jni.cc

Index: webrtc/api/android/jni/peerconnection_jni.cc
diff --git a/webrtc/api/android/jni/peerconnection_jni.cc b/webrtc/api/android/jni/peerconnection_jni.cc
index 0762f80efbd243e43cdb9babd0f0193c5c896649..a552e4c18ae970ecccf59b5acd0e98179ead6e23 100644
--- a/webrtc/api/android/jni/peerconnection_jni.cc
+++ b/webrtc/api/android/jni/peerconnection_jni.cc
@@ -43,6 +43,8 @@
 #include <memory>
 #include <utility>
 
+#include "third_party/libyuv/include/libyuv/convert_from.h"
+#include "third_party/libyuv/include/libyuv/scale.h"
 #include "webrtc/api/androidvideotracksource.h"
 #include "webrtc/api/android/jni/androidmediadecoder_jni.h"
 #include "webrtc/api/android/jni/androidmediaencoder_jni.h"
@@ -2003,6 +2005,77 @@ JOW(void, VideoRenderer_nativeCopyPlane)(
   }
 }
 
+JOW(void, FileVideoCapturer_nativeI420ToNV21)(
+    JNIEnv *jni, jclass, jbyteArray j_src_buffer, jint width, jint height,
+    jbyteArray j_dst_buffer) {
+  size_t src_size = jni->GetArrayLength(j_src_buffer);
+  size_t dst_size = jni->GetArrayLength(j_dst_buffer);
+  int src_stride = width;
+  int dst_stride = width;
+  RTC_CHECK_GE(src_size, src_stride * height * 3 / 2);
+  RTC_CHECK_GE(dst_size, dst_stride * height * 3 / 2);
+  uint8_t* src =
+      reinterpret_cast<uint8_t*>(jni->GetByteArrayElements(j_src_buffer, 0));
+  uint8_t* dst =
+      reinterpret_cast<uint8_t*>(jni->GetByteArrayElements(j_dst_buffer, 0));
+  uint8_t* src_y = src;
+  size_t src_stride_y = src_stride;
+  uint8_t* src_u = src + src_stride * height;
+  size_t src_stride_u = src_stride / 2;
+  uint8_t* src_v = src + src_stride * height * 5 / 4;
+  size_t src_stride_v = src_stride / 2;
+
+  uint8_t* dst_y = dst;
+  size_t dst_stride_y = dst_stride;
+  size_t dst_stride_uv = dst_stride;
+  uint8_t* dst_uv = dst + dst_stride * height;
+
+  libyuv::I420ToNV21(src_y, src_stride_y, src_u, src_stride_u, src_v,
+                     src_stride_v, dst_y, dst_stride_y, dst_uv, dst_stride_uv,
+                     width, height);
+}
+
+JOW(void, VideoFileRenderer_nativeI420Scale)(
+    JNIEnv *jni, jclass,
+    jobject j_src_buffer_y, jint j_src_stride_y,
+    jobject j_src_buffer_u, jint j_src_stride_u,
+    jobject j_src_buffer_v, jint j_src_stride_v,
+    jint width, jint height,
+    jbyteArray j_dst_buffer, jint dstWidth, jint dstHeight) {
+  size_t src_size_y = jni->GetDirectBufferCapacity(j_src_buffer_y);
+  size_t src_size_u = jni->GetDirectBufferCapacity(j_src_buffer_u);
+  size_t src_size_v = jni->GetDirectBufferCapacity(j_src_buffer_v);
+  size_t dst_size = jni->GetDirectBufferCapacity(j_dst_buffer);
+  int dst_stride = dstWidth;
+  RTC_CHECK_GE(src_size_y, j_src_stride_y * height);
+  RTC_CHECK_GE(src_size_u, j_src_stride_u * height / 4);
+  RTC_CHECK_GE(src_size_v, j_src_stride_v * height / 4);
+  RTC_CHECK_GE(dst_size, dst_stride * height * 3 / 2);
+  uint8_t* src_y =
+      reinterpret_cast<uint8_t*>(jni->GetDirectBufferAddress(j_src_buffer_y));
+  uint8_t* src_u =
+      reinterpret_cast<uint8_t*>(jni->GetDirectBufferAddress(j_src_buffer_u));
+  uint8_t* src_v =
+      reinterpret_cast<uint8_t*>(jni->GetDirectBufferAddress(j_src_buffer_v));
+  uint8_t* dst =
+      reinterpret_cast<uint8_t*>(jni->GetDirectBufferAddress(j_dst_buffer));
+
+  uint8_t* dst_y = dst;
+  size_t dst_stride_y = dst_stride;
+  uint8_t* dst_u = dst + dst_stride * dstHeight;
+  size_t dst_stride_u = dst_stride / 2;
+  uint8_t* dst_v = dst + dst_stride * dstHeight * 5 / 4;
+  size_t dst_stride_v = dst_stride / 2;
+
+  int ret = libyuv::I420Scale(
+      src_y, j_src_stride_y, src_u, j_src_stride_u, src_v, j_src_stride_v,
+      width, height, dst_y, dst_stride_y, dst_u, dst_stride_u, dst_v,
+      dst_stride_v, dstWidth, dstHeight, libyuv::kFilterBilinear);
+  if (ret) {
+    LOG(LS_ERROR) << "Error scaling I420 frame: " << ret;
+  }
+}
+
 JOW(jstring, MediaStreamTrack_nativeId)(JNIEnv* jni, jclass, jlong j_p) {
   return JavaStringFromStdString(
       jni, reinterpret_cast<MediaStreamTrackInterface*>(j_p)->id());