1.Use libyuv instead of ffmpeg to do nv12<->yuv420p convertion;2.Use local package to build libyuv(branch stable 2021.4.28 commit eb6e7bb63738e29efd82ea3cf2a115238a89fa51)

thirdparty/libyuv/util/psnr.h

@@ -0,0 +1,47 @@
+/*
+ *  Copyright 2013 The LibYuv Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS. All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// Get PSNR for video sequence. Assuming RAW 4:2:0 Y:Cb:Cr format
+
+#ifndef UTIL_PSNR_H_  // NOLINT
+#define UTIL_PSNR_H_
+
+#include <math.h>  // For log10()
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if !defined(INT_TYPES_DEFINED) && !defined(UINT8_TYPE_DEFINED)
+typedef unsigned char uint8_t;
+#define UINT8_TYPE_DEFINED
+#endif
+
+static const double kMaxPSNR = 128.0;
+
+// libyuv provides this function when linking library for jpeg support.
+// TODO(fbarchard): make psnr lib compatible subset of libyuv.
+#if !defined(HAVE_JPEG)
+// Computer Sum of Squared Error (SSE).
+// Pass this to ComputePSNR for final result.
+double ComputeSumSquareError(const uint8_t* src_a,
+                             const uint8_t* src_b,
+                             int count);
+#endif
+
+// PSNR formula: psnr = 10 * log10 (Peak Signal^2 * size / sse)
+// Returns 128.0 (kMaxPSNR) if sse is 0 (perfect match).
+double ComputePSNR(double sse, double size);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // UTIL_PSNR_H_  // NOLINT