diff options
Diffstat (limited to 'media/base/video_frame.cc')
| -rw-r--r-- | media/base/video_frame.cc | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/media/base/video_frame.cc b/media/base/video_frame.cc new file mode 100644 index 0000000..0b8239c --- /dev/null +++ b/media/base/video_frame.cc @@ -0,0 +1,170 @@ +// Copyright (c) 2010 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" + +namespace media { + +// static +void VideoFrame::CreateFrame(VideoFrame::Format format, + size_t width, + size_t height, + base::TimeDelta timestamp, + base::TimeDelta duration, + scoped_refptr<VideoFrame>* frame_out) { + DCHECK(width > 0 && height > 0); + DCHECK(width * height < 100000000); + DCHECK(frame_out); + bool alloc_worked = false; + scoped_refptr<VideoFrame> frame = + new VideoFrame(format, width, height); + if (frame) { + frame->SetTimestamp(timestamp); + frame->SetDuration(duration); + switch (format) { + case VideoFrame::RGB555: + case VideoFrame::RGB565: + alloc_worked = frame->AllocateRGB(2u); + break; + case VideoFrame::RGB24: + alloc_worked = frame->AllocateRGB(3u); + break; + case VideoFrame::RGB32: + case VideoFrame::RGBA: + alloc_worked = frame->AllocateRGB(4u); + break; + case VideoFrame::YV12: + case VideoFrame::YV16: + alloc_worked = frame->AllocateYUV(); + break; + default: + NOTREACHED(); + alloc_worked = false; + break; + } + } + *frame_out = alloc_worked ? frame : NULL; +} + +// static +void VideoFrame::CreateEmptyFrame(scoped_refptr<VideoFrame>* frame_out) { + *frame_out = new VideoFrame(VideoFrame::EMPTY, 0, 0); +} + +// static +void VideoFrame::CreateBlackFrame(int width, int height, + scoped_refptr<VideoFrame>* frame_out) { + DCHECK_GT(width, 0); + DCHECK_GT(height, 0); + + // Create our frame. + scoped_refptr<VideoFrame> frame; + const base::TimeDelta kZero; + VideoFrame::CreateFrame(VideoFrame::YV12, width, height, kZero, kZero, + &frame); + DCHECK(frame); + + // Now set the data to YUV(0,128,128). + const uint8 kBlackY = 0x00; + const uint8 kBlackUV = 0x80; + + // Fill the Y plane. + uint8* y_plane = frame->data(VideoFrame::kYPlane); + for (size_t i = 0; i < frame->height_; ++i) { + memset(y_plane, kBlackY, frame->width_); + y_plane += frame->stride(VideoFrame::kYPlane); + } + + // Fill the U and V planes. + uint8* u_plane = frame->data(VideoFrame::kUPlane); + uint8* v_plane = frame->data(VideoFrame::kVPlane); + for (size_t i = 0; i < (frame->height_ / 2); ++i) { + memset(u_plane, kBlackUV, frame->width_ / 2); + memset(v_plane, kBlackUV, frame->width_ / 2); + u_plane += frame->stride(VideoFrame::kUPlane); + v_plane += frame->stride(VideoFrame::kVPlane); + } + + // Success! + *frame_out = 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)); +} + +bool 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); + planes_ = VideoFrame::kNumRGBPlanes; + strides_[VideoFrame::kRGBPlane] = bytes_per_row; + data_[VideoFrame::kRGBPlane] = new uint8[bytes_per_row * height_]; + DCHECK(data_[VideoFrame::kRGBPlane]); + DCHECK(!(reinterpret_cast<intptr_t>(data_[VideoFrame::kRGBPlane]) & 7)); + COMPILE_ASSERT(0 == VideoFrame::kRGBPlane, RGB_data_must_be_index_0); + return (NULL != data_[VideoFrame::kRGBPlane]); +} + +bool 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 alloc_height = RoundUp(height_, 2); + size_t y_bytes_per_row = RoundUp(width_, 4); + size_t uv_stride = RoundUp(y_bytes_per_row / 2, 4); + size_t y_bytes = alloc_height * y_bytes_per_row; + size_t uv_bytes = alloc_height * uv_stride; + if (format_ == VideoFrame::YV12) { + uv_bytes /= 2; + } + uint8* data = new uint8[y_bytes + (uv_bytes * 2)]; + if (data) { + planes_ = VideoFrame::kNumYUVPlanes; + 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_bytes_per_row; + strides_[VideoFrame::kUPlane] = uv_stride; + strides_[VideoFrame::kVPlane] = uv_stride; + return true; + } + NOTREACHED(); + return false; +} + +VideoFrame::VideoFrame(VideoFrame::Format format, + size_t width, + size_t height) { + format_ = format; + width_ = width; + height_ = height; + planes_ = 0; + memset(&strides_, 0, sizeof(strides_)); + memset(&data_, 0, sizeof(data_)); +} + +VideoFrame::~VideoFrame() { + // 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]; +} + +bool VideoFrame::IsEndOfStream() const { + return format_ == VideoFrame::EMPTY; +} + +} // namespace media |