Add CDM video decoder.

webkit/media/crypto/ppapi/ffmpeg_cdm_video_frame.cc

+// Copyright (c) 2012 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 "webkit/media/crypto/ppapi/ffmpeg_cdm_video_frame.h"
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "media/base/limits.h"
+#include "webkit/media/crypto/ppapi/ffmpeg_cdm_video_decoder.h"
+
+
+namespace webkit_media {
+
+static const uint32_t kBufferAlignment = 32;
+
+static inline int RoundUp(int value, int alignment) {
+  // Check that |alignment| is a power of 2.
+  DCHECK((alignment + (alignment - 1)) == (alignment | (alignment - 1)));
+  return ((value + (alignment - 1)) & ~(alignment-1));
+}
+
+static int RowBytes(cdm::VideoFormat format,
+                    cdm::VideoFrame::VideoPlane plane,
+                    int width) {
+  switch (format) {
+    case cdm::kYv12:
+    case cdm::kI420:
+      if (plane == cdm::VideoFrame::kYPlane)
+        return width;
+      return RoundUp(width, 2) / 2;
+
+    default:
+      NOTREACHED() << "Unsupported video frame format: " << format;
+      return 0;
+  }
+}
+
+// static
+FFmpegCdmVideoFrame* FFmpegCdmVideoFrame::Create(cdm::Allocator* allocator,
+                                                 cdm::VideoFormat format,
+                                                 const cdm::Size& size) {
+  if (!IsValidConfig(format, size)) {
+    LOG(ERROR) << "Create() invalid config.";
+    return NULL;
+  }
+
+  scoped_ptr<FFmpegCdmVideoFrame> frame(new FFmpegCdmVideoFrame(format, size));
+
+  if (!frame->AllocateYuv(allocator))
+    return NULL;
+
+  return frame.release();
+}
+
+FFmpegCdmVideoFrame::FFmpegCdmVideoFrame(cdm::VideoFormat format,
+                                         const cdm::Size& size)
+    : format_(format),
+      size_(size),
+      frame_buffer_(NULL) {
+  for (int32_t i = 0; i < cdm::VideoFrame::kMaxPlanes; ++i) {
+    plane_offsets_[i] = 0;
+    strides_[i] = 0;
+  }
+}
+
+FFmpegCdmVideoFrame::~FFmpegCdmVideoFrame() {
+  if (frame_buffer_)
+    frame_buffer_->Destroy();
+}
+
+int32_t FFmpegCdmVideoFrame::plane_offset(
+    cdm::VideoFrame::VideoPlane plane) const {
+  DCHECK(0 <= plane && plane < cdm::VideoFrame::kMaxPlanes);
+  return plane_offsets_[plane];
+}
+
+int32_t FFmpegCdmVideoFrame::stride(
+    cdm::VideoFrame::VideoPlane plane) const {
+  DCHECK(0 <= plane && plane < cdm::VideoFrame::kMaxPlanes);
+  return strides_[plane];
+}
+
+// static
+bool FFmpegCdmVideoFrame::IsValidConfig(cdm::VideoFormat format,
+                                        const cdm::Size& data_size) {
+  return ((format == cdm::kYv12 || format == cdm::kI420) &&
+          data_size.width > 0 && data_size.height > 0 &&
+          data_size.width <= media::limits::kMaxDimension &&
+          data_size.height <= media::limits::kMaxDimension &&
+          data_size.width * data_size.height <= media::limits::kMaxCanvas);
+}
+
+void FFmpegCdmVideoFrame::PassVideoFrame(cdm::VideoFrame* target) {
+  DCHECK(frame_buffer_);
+  DCHECK(target);
+  target->set_format(format_);
+  target->set_size(size_);
+  target->set_frame_buffer(frame_buffer_);
+
+  const int kMaxPlanes = cdm::VideoFrame::kMaxPlanes;
+  for (int i = 0; i < kMaxPlanes; ++i) {
+    cdm::VideoFrame::VideoPlane plane =
+        static_cast<cdm::VideoFrame::VideoPlane>(i);
+    target->set_plane_offset(plane, plane_offsets_[i]);
+    target->set_stride(plane, strides_[i]);
+    plane_offsets_[i] = 0;
+    strides_[i] = 0;
+  }
+
+  format_ = cdm::kEmptyVideoFrame;
+  size_.width = 0;
+  size_.height = 0;
+  frame_buffer_ = NULL;
+}
+
+bool FFmpegCdmVideoFrame::AllocateYuv(cdm::Allocator* allocator) {
+  DCHECK(allocator);
+  DCHECK(format_ == cdm::kYv12 || format_ == cdm::kI420);
+
+  // Align Y rows at least at 32 byte boundaries for safety on all platforms.
+  DVLOG(3) << "AllocateYuv() width=" << size_.width << " height="
+           << size_.height;
+  size_t y_stride = RoundUp(
+      RowBytes(format_, cdm::VideoFrame::kYPlane, size_.width),
+      kBufferAlignment);
+  size_t uv_stride = RoundUp(
+      RowBytes(format_, cdm::VideoFrame::kUPlane, size_.width),
+      kBufferAlignment);
+
+  // The RoundUp() here is because some formats (e.g. h264) allow interlaced
+  // coding, and then the size needs to be a multiple of two macroblocks
+  // (vertically). See libavcodec/utils.c:avcodec_align_dimensions2().

[xhwang, 2012/10/17 20:23:10]

good to know! Thanks.

+  size_t y_height = RoundUp(size_.height, kBufferAlignment);
+  size_t uv_height = y_height / 2;
+  size_t y_bytes = y_height * y_stride;
+  size_t uv_bytes = uv_height * uv_stride;
+
+  frame_buffer_ = allocator->Allocate(y_bytes + (uv_bytes * 2));
+  if (!frame_buffer_) {
+    LOG(ERROR) << "AllocateYuv() cdm::Allocator::Allocate failed.";
+    return false;
+  }
+
+  COMPILE_ASSERT(0 == cdm::VideoFrame::kYPlane, y_plane_data_must_be_index_0);
+  uint8_t* data = frame_buffer_->data();
+  DCHECK_EQ(0U, reinterpret_cast<uintptr_t>(data) & (kBufferAlignment - 1));
+
+  plane_offsets_[cdm::VideoFrame::kYPlane] =  0;
+
+  if (format_ == cdm::kYv12) {
+    plane_offsets_[cdm::VideoFrame::kVPlane] = y_bytes;
+    plane_offsets_[cdm::VideoFrame::kUPlane] = y_bytes + uv_bytes;
+  } else {
+    plane_offsets_[cdm::VideoFrame::kUPlane] = y_bytes;
+    plane_offsets_[cdm::VideoFrame::kVPlane] = y_bytes + uv_bytes;
+  }
+
+  strides_[cdm::VideoFrame::kYPlane] = y_stride;
+  strides_[cdm::VideoFrame::kUPlane] = uv_stride;
+  strides_[cdm::VideoFrame::kVPlane] = uv_stride;
+
+  return true;
+}
+
+}  // namespace webkit_media