AP_HAL_Linux: add benchmark for crop_8bpp() and yuyv_to_grey()

We had to check for board subtypes in the benchmark since VideoIn.cpp
does these checks.

libraries/AP_HAL_Linux/benchmarks/benchmark_videoin.cpp

@@ -0,0 +1,67 @@
+#include <AP_gbenchmark.h>
+#include <AP_HAL/AP_HAL.h>
+
+#if CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_BEBOP ||\
+    CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_MINLURE
+
+#include <AP_HAL_Linux/VideoIn.h>
+
+static void BM_Crop8bpp(benchmark::State& state)
+{
+    uint8_t *buffer, *new_buffer;
+    uint32_t width = 640;
+    uint32_t height = 480;
+    uint32_t left = width / 2 - state.range_x() / 2;
+    uint32_t top = height / 2 - state.range_y() / 2;
+
+    buffer = (uint8_t *)malloc(width * height);
+    if (!buffer) {
+        fprintf(stderr, "error: couldn't malloc buffer\n");
+        return;
+    }
+
+    new_buffer = (uint8_t *)malloc(state.range_x() * state.range_y());
+    if (!new_buffer) {
+        fprintf(stderr, "error: couldn't malloc new_buffer\n");
+        return;
+    }
+
+    while (state.KeepRunning()) {
+        Linux::VideoIn::crop_8bpp(buffer, new_buffer, width,
+            left, state.range_x(), top, state.range_y());
+    }
+
+    free(buffer);
+    free(new_buffer);
+}
+
+BENCHMARK(BM_Crop8bpp)->ArgPair(64, 64)->ArgPair(240, 240)->ArgPair(640, 480);
+
+static void BM_YuyvToGrey(benchmark::State& state)
+{
+    uint8_t *buffer, *new_buffer;
+
+    buffer = (uint8_t *)malloc(state.range_x());
+    if (!buffer) {
+        fprintf(stderr, "error: couldn't malloc buffer\n");
+        return;
+    }
+
+    new_buffer = (uint8_t *)malloc(state.range_x() / 2);
+    if (!new_buffer) {
+        fprintf(stderr, "error: couldn't malloc new_buffer\n");
+        return;
+    }
+
+    while (state.KeepRunning()) {
+        Linux::VideoIn::yuyv_to_grey(buffer, state.range_x(), new_buffer);
+    }
+
+    free(buffer);
+    free(new_buffer);
+}
+
+BENCHMARK(BM_YuyvToGrey)->Arg(64 * 64)->Arg(320 * 240)->Arg(640 * 480);
+#endif
+
+BENCHMARK_MAIN()

libraries/AP_HAL_Linux/benchmarks/wscript

@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# encoding: utf-8
+
+import ardupilotwaf
+
+def build(bld):
+    ardupilotwaf.find_benchmarks(
+        bld,
+        use='ap',
+    )