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

media/base/video_frame.cc

Index: media/base/video_frame.cc
===================================================================
--- media/base/video_frame.cc	(revision 140753)
+++ media/base/video_frame.cc	(working copy)
@@ -8,6 +8,9 @@
 #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
 
 namespace media {
 
@@ -16,18 +19,19 @@
     VideoFrame::Format format,
     size_t width,
     size_t height,
+    size_t alignment,
     base::TimeDelta timestamp,
     base::TimeDelta duration) {
-  DCHECK(IsValidConfig(format, width, height));
+  DCHECK(IsValidConfig(format, width, height, alignment));
   scoped_refptr<VideoFrame> frame(new VideoFrame(
       format, width, height, timestamp, duration));
   switch (format) {
     case VideoFrame::RGB32:
-      frame->AllocateRGB(4u);
+          frame->AllocateRGB(4u, alignment);

[scherkus (not reviewing), 2012/06/14 02:21:33]

fix indent here

       break;
     case VideoFrame::YV12:
     case VideoFrame::YV16:
-      frame->AllocateYUV();
+          frame->AllocateYUV(alignment);

[scherkus (not reviewing), 2012/06/14 02:21:33]

fix indent here

       break;
     default:
       LOG(FATAL) << "Unsupported frame format: " << format;
@@ -39,12 +43,13 @@
 bool VideoFrame::IsValidConfig(
     VideoFrame::Format format,
     size_t width,
-    size_t height) {
+    size_t height,
+    size_t alignment) {
 
   return (format != VideoFrame::INVALID &&
           width > 0 && height > 0 &&
           width <= limits::kMaxDimension && height <= limits::kMaxDimension &&
-          width * height <= limits::kMaxCanvas);
+          width * height <= limits::kMaxCanvas && alignment > 0);

[scherkus (not reviewing), 2012/06/14 02:21:33]

shouldn't alignment be checked for power of 2?

check out the neat bitwise trick in RoundUp()

 }
 
 // static
@@ -78,7 +83,8 @@
   // Create our frame.
   const base::TimeDelta kZero;
   scoped_refptr<VideoFrame> frame =
-      VideoFrame::CreateFrame(VideoFrame::YV12, width, height, kZero, kZero);
+      VideoFrame::CreateFrame(VideoFrame::YV12, width, height,

[scherkus (not reviewing), 2012/06/14 02:21:33]

revert change here

+                              kZero, kZero);
 
   // Now set the data to YUV(0,128,128).
   const uint8 kBlackY = 0x00;
@@ -93,19 +99,31 @@
   return ((value + (alignment - 1)) & ~(alignment-1));
 }
 
-void VideoFrame::AllocateRGB(size_t bytes_per_pixel) {
+static inline size_t Max(size_t a, size_t b) {

[scherkus (not reviewing), 2012/06/14 02:21:33]

use std::max() instead?

+  return a > b ? a : b;
+}
+
+void VideoFrame::AllocateRGB(size_t bytes_per_pixel, size_t alignment) {
   // 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);
+  size_t bytes_per_row = RoundUp(width_ * bytes_per_pixel, Max(alignment, 8u));
+  size_t aligned_height = RoundUp(height_, alignment);
   strides_[VideoFrame::kRGBPlane] = bytes_per_row;
-  data_[VideoFrame::kRGBPlane] = new uint8[bytes_per_row * height_];
+#if !defined(OS_ANDROID)
+  // TODO use DataAligned or so, so this #ifdef hackery doesn't need to be

[scherkus (not reviewing), 2012/06/14 02:21:33]

s/TODO/TODO(dalecurtis):/

+  // repeated in every single user of aligned data.
+  data_[VideoFrame::kRGBPlane] = reinterpret_cast<uint8 *>(

[scherkus (not reviewing), 2012/06/14 02:21:33]

pointers go w/ types

good: uint8* var
bad: uint8 *var

+        av_malloc(bytes_per_row * aligned_height));

[scherkus (not reviewing), 2012/06/14 02:21:33]

4-space indent

+#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() {
+void VideoFrame::AllocateYUV(size_t alignment) {
   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
@@ -116,14 +134,23 @@
   // 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.

[scherkus (not reviewing), 2012/06/14 02:21:33]

comment needs updating to say this does a minimum of 4-byte alignment, etc...

-  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);
+  size_t y_stride = RoundUp(row_bytes(VideoFrame::kYPlane),
+                            Max(alignment, 4u));
+  size_t uv_stride = RoundUp(row_bytes(VideoFrame::kUPlane),
+                             Max(alignment, 4u));
+  size_t y_height = RoundUp(height_, Max(alignment, 2u));
+  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 use DataAligned or so, so this #ifdef hackery doesn't need to be

[scherkus (not reviewing), 2012/06/14 02:21:33]

ditto

+  // repeated in every single user of aligned data.
+  uint8* data = reinterpret_cast<uint8 *>(

[scherkus (not reviewing), 2012/06/14 02:21:33]

ditto for pointers

+        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;
@@ -158,7 +185,13 @@
   // 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 {