Provide a Chrome-owned buffer to FFmpeg for video decoding, instead of

media/base/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 "media/base/video_frame.h"
 
 #include "base/logging.h"
 #include "base/string_piece.h"
 #include "media/base/limits.h"
 #include "media/base/video_util.h"
+#if !defined(OS_ANDROID)
+#include "media/ffmpeg/ffmpeg_common.h"
+#endif
+
+#include <algorithm>
 
 namespace media {
 
 // static
 scoped_refptr<VideoFrame> VideoFrame::CreateFrame(
     VideoFrame::Format format,
     size_t width,
     size_t height,
     base::TimeDelta timestamp,
     base::TimeDelta duration) {
@@ skipping 66 matching lines @@
   return frame;
 }
 
 static inline size_t RoundUp(size_t value, size_t alignment) {
   // Check that |alignment| is a power of 2.
   DCHECK((alignment + (alignment - 1)) == (alignment | (alignment - 1)));
   return ((value + (alignment - 1)) & ~(alignment-1));
 }
 
 void VideoFrame::AllocateRGB(size_t bytes_per_pixel) {
-  // Round up to align at a 64-bit (8 byte) boundary for each row.  This
-  // is sufficient for MMX reads (movq).
-  size_t bytes_per_row = RoundUp(width_ * bytes_per_pixel, 8);
+  // Round up to align at least at a 64-bit (8 byte) boundary for each row.
+  // This is sufficient for MMX reads (movq).
+  size_t bytes_per_row = RoundUp(width_, 16) * bytes_per_pixel;

[DaleCurtis, 2012/06/16 04:23:10]

Don't have time to do a full review this second, but this 16 should be a
constant. static const int kFrameAlignment maybe?

+  size_t aligned_height = RoundUp(height_, 16);
   strides_[VideoFrame::kRGBPlane] = bytes_per_row;
-  data_[VideoFrame::kRGBPlane] = new uint8[bytes_per_row * height_];
+#if !defined(OS_ANDROID)
+  // TODO(dalecurtis): use DataAligned or so, so this #ifdef hackery
+  // doesn't need to be repeated in every single user of aligned data.
+  data_[VideoFrame::kRGBPlane] = reinterpret_cast<uint8*>(
+      av_malloc(bytes_per_row * aligned_height));
+#else
+  data_[VideoFrame::kRGBPlane] = new uint8_t[bytes_per_row * aligned_height];
+#endif
   DCHECK(!(reinterpret_cast<intptr_t>(data_[VideoFrame::kRGBPlane]) & 7));
   COMPILE_ASSERT(0 == VideoFrame::kRGBPlane, RGB_data_must_be_index_0);
 }
 
 static const int kFramePadBytes = 15;  // Allows faster SIMD YUV convert.
 
 void VideoFrame::AllocateYUV() {
   DCHECK(format_ == VideoFrame::YV12 || format_ == VideoFrame::YV16);
-  // Align Y rows at 32-bit (4 byte) boundaries.  The stride for both YV12 and
-  // YV16 is 1/2 of the stride of Y.  For YV12, every row of bytes for U and V
-  // applies to two rows of Y (one byte of UV for 4 bytes of Y), so in the
-  // case of YV12 the strides are identical for the same width surface, but the
-  // number of bytes allocated for YV12 is 1/2 the amount for U & V as YV16.
-  // We also round the height of the surface allocated to be an even number
-  // to avoid any potential of faulting by code that attempts to access the Y
-  // values of the final row, but assumes that the last row of U & V applies to
-  // a full two rows of Y.
-  size_t y_height = rows(VideoFrame::kYPlane);
-  size_t y_stride = RoundUp(row_bytes(VideoFrame::kYPlane), 4);
-  size_t uv_stride = RoundUp(row_bytes(VideoFrame::kUPlane), 4);
-  size_t uv_height = rows(VideoFrame::kUPlane);
+  // Align Y rows at least at 16 byte boundaries.  The stride for both
+  // YV12 and YV16 is 1/2 of the stride of Y.  For YV12, every row of bytes for
+  // U and V applies to two rows of Y (one byte of UV for 4 bytes of Y), so in
+  // the case of YV12 the strides are identical for the same width surface, but
+  // the number of bytes allocated for YV12 is 1/2 the amount for U & V as
+  // YV16. We also round the height of the surface allocated to be an even
+  // number to avoid any potential of faulting by code that attempts to access
+  // the Y values of the final row, but assumes that the last row of U & V
+  // applies to a full two rows of Y.
+  size_t y_stride = RoundUp(row_bytes(VideoFrame::kYPlane), 16);
+  size_t uv_stride = RoundUp(row_bytes(VideoFrame::kUPlane), 16);
+  size_t y_height = RoundUp(height_, 16);
+  size_t uv_height = format_ == VideoFrame::YV12 ? y_height / 2 : y_height;
   size_t y_bytes = y_height * y_stride;
   size_t uv_bytes = uv_height * uv_stride;
 
-  uint8* data = new uint8[y_bytes + (uv_bytes * 2) + kFramePadBytes];
+#if !defined(OS_ANDROID)
+  // TODO(dalecurtis): use DataAligned or so, so this #ifdef hackery
+  // doesn't need to be repeated in every single user of aligned data.
+  uint8* data = reinterpret_cast<uint8*>(
+      av_malloc(y_bytes + (uv_bytes * 2) + kFramePadBytes));
+#else
+  uint8* data = new uint8_t[y_bytes + (uv_bytes * 2) + kFramePadBytes];
+#endif
   COMPILE_ASSERT(0 == VideoFrame::kYPlane, y_plane_data_must_be_index_0);
   data_[VideoFrame::kYPlane] = data;
   data_[VideoFrame::kUPlane] = data + y_bytes;
   data_[VideoFrame::kVPlane] = data + y_bytes + uv_bytes;
   strides_[VideoFrame::kYPlane] = y_stride;
   strides_[VideoFrame::kUPlane] = uv_stride;
   strides_[VideoFrame::kVPlane] = uv_stride;
 }
 
 VideoFrame::VideoFrame(VideoFrame::Format format,
@@ skipping 14 matching lines @@
 
 VideoFrame::~VideoFrame() {
   if (format_ == NATIVE_TEXTURE && !texture_no_longer_needed_.is_null()) {
     texture_no_longer_needed_.Run();
     texture_no_longer_needed_.Reset();
   }
 
   // In multi-plane allocations, only a single block of memory is allocated
   // on the heap, and other |data| pointers point inside the same, single block
   // so just delete index 0.
-  delete[] data_[0];
+  if (data_[0]) {
+#if !defined(OS_ANDROID)
+    av_free(data_[0]);
+#else
+    delete[] data_[0];
+#endif
+  }
 }
 
 bool VideoFrame::IsValidPlane(size_t plane) const {
   switch (format_) {
     case RGB32:
       return plane == kRGBPlane;
 
     case YV12:
     case YV16:
       return plane == kYPlane || plane == kUPlane || plane == kVPlane;
@@ skipping 85 matching lines @@
       break;
     for(int row = 0; row < rows(plane); row++) {
       base::MD5Update(context, base::StringPiece(
           reinterpret_cast<char*>(data(plane) + stride(plane) * row),
           row_bytes(plane)));
     }
   }
 }
 
 }  // namespace media