media: add video capture device for ARC++ camera HAL v3

media/capture/video/chromeos/pixel_format_utils.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/capture/video/chromeos/pixel_format_utils.h"
+
+#include <libdrm/drm_fourcc.h>
+
+#include <algorithm>
+
+namespace media {
+
+namespace {
+
+struct SupportedFormat {
+  VideoPixelFormat chromium_format;
+  arc::mojom::HalPixelFormat hal_format;
+  uint32_t drm_format;
+} const kSupportedFormats[] = {
+    // The Android camera HAL v3 has three types of mandatory pixel formats:
+    //
+    //   1. HAL_PIXEL_FORMAT_YCbCr_420_888 (YUV flexible format).
+    //   2. HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED (platform-specific format).
+    //   3. HAL_PIXEL_FORMAT_BLOB (for JPEG).
+    //
+    // We can't use HAL_PIXEL_FORMAT_IMPLEMENTATION_DEFINED as it is highly
+    // platform specific and there is no way for Chrome to query the exact
+    // pixel layout of the implementation-defined buffer.
+    //
+    // On Android the framework requests the preview stream with the
+    // implementation-defined format, and as a result some camera HALs support
+    // only implementation-defined preview buffers.  We should use the video
+    // capture stream in Chrome VCD as it is mandatory for the camera HAL to
+    // support YUV flexbile format video streams.
+
+    // TODO(jcliang): Change NV12 to I420 after the camera HAL supports handling
+    //                I420 buffers.
+    {PIXEL_FORMAT_NV12,
+     arc::mojom::HalPixelFormat::HAL_PIXEL_FORMAT_YCbCr_420_888,
+     DRM_FORMAT_NV12},
+};
+
+}  // namespace
+
+VideoPixelFormat PixFormatHalToChromium(arc::mojom::HalPixelFormat from) {
+  auto* it =
+      std::find_if(std::begin(kSupportedFormats), std::end(kSupportedFormats),
+                   [from](SupportedFormat f) { return f.hal_format == from; });
+  if (it == std::end(kSupportedFormats)) {
+    return PIXEL_FORMAT_UNKNOWN;
+  }
+  return it->chromium_format;
+}
+
+uint32_t PixFormatChromiumToDrm(VideoPixelFormat from) {
+  auto* it = std::find_if(
+      std::begin(kSupportedFormats), std::end(kSupportedFormats),
+      [from](SupportedFormat f) { return f.chromium_format == from; });
+  if (it == std::end(kSupportedFormats)) {
+    return 0;
+  }
+  return it->drm_format;
+}
+
+}  // namespace media