webrtc/talk/media/base/videocommon.cc
henrike@webrtc.org 28e2075280 Adds trunk/talk folder of revision 359 from libjingles google code to
trunk/talk


git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
2013-07-10 00:45:36 +00:00

238 lines
8.9 KiB
C++

// libjingle
// Copyright 2010 Google Inc.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// 3. The name of the author may not be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
// EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "talk/media/base/videocommon.h"
#include <limits.h> // For INT_MAX
#include <math.h>
#include <sstream>
#include "talk/base/common.h"
namespace cricket {
struct FourCCAliasEntry {
uint32 alias;
uint32 canonical;
};
static const FourCCAliasEntry kFourCCAliases[] = {
{FOURCC_IYUV, FOURCC_I420},
{FOURCC_YU16, FOURCC_I422},
{FOURCC_YU24, FOURCC_I444},
{FOURCC_YUYV, FOURCC_YUY2},
{FOURCC_YUVS, FOURCC_YUY2},
{FOURCC_HDYC, FOURCC_UYVY},
{FOURCC_2VUY, FOURCC_UYVY},
{FOURCC_JPEG, FOURCC_MJPG}, // Note: JPEG has DHT while MJPG does not.
{FOURCC_DMB1, FOURCC_MJPG},
{FOURCC_BA81, FOURCC_BGGR},
{FOURCC_RGB3, FOURCC_RAW},
{FOURCC_BGR3, FOURCC_24BG},
{FOURCC_CM32, FOURCC_BGRA},
{FOURCC_CM24, FOURCC_RAW},
};
uint32 CanonicalFourCC(uint32 fourcc) {
for (int i = 0; i < ARRAY_SIZE(kFourCCAliases); ++i) {
if (kFourCCAliases[i].alias == fourcc) {
return kFourCCAliases[i].canonical;
}
}
// Not an alias, so return it as-is.
return fourcc;
}
static float kScaleFactors[] = {
1.f / 1.f, // Full size.
1.f / 2.f, // 1/2 scale.
1.f / 4.f, // 1/4 scale.
1.f / 8.f, // 1/8 scale.
1.f / 16.f // 1/16 scale.
};
static const int kNumScaleFactors = ARRAY_SIZE(kScaleFactors);
// Finds the scale factor that, when applied to width and height, produces
// fewer than num_pixels.
static float FindLowerScale(int width, int height, int target_num_pixels) {
if (!target_num_pixels) {
return 0.f;
}
int best_distance = INT_MAX;
int best_index = kNumScaleFactors - 1; // Default to max scale.
for (int i = 0; i < kNumScaleFactors; ++i) {
int test_num_pixels = static_cast<int>(width * kScaleFactors[i] *
height * kScaleFactors[i]);
int diff = target_num_pixels - test_num_pixels;
if (diff >= 0 && diff < best_distance) {
best_distance = diff;
best_index = i;
if (best_distance == 0) { // Found exact match.
break;
}
}
}
return kScaleFactors[best_index];
}
// Compute a size to scale frames to that is below maximum compression
// and rendering size with the same aspect ratio.
void ComputeScale(int frame_width, int frame_height, int fps,
int* scaled_width, int* scaled_height) {
ASSERT(scaled_width != NULL);
ASSERT(scaled_height != NULL);
// For VP8 the values for max width and height can be found here
// webrtc/src/video_engine/vie_defines.h (kViEMaxCodecWidth and
// kViEMaxCodecHeight)
const int kMaxWidth = 4096;
const int kMaxHeight = 3072;
// Maximum pixels limit is set to Retina MacBookPro 15" resolution of
// 2880 x 1800 as of 4/18/2013.
// For high fps, maximum pixels limit is set based on common 24" monitor
// resolution of 2048 x 1280 as of 6/13/2013. The Retina resolution is
// therefore reduced to 1440 x 900.
int kMaxPixels = (fps > 5) ? 2048 * 1280 : 2880 * 1800;
int new_frame_width = frame_width;
int new_frame_height = frame_height;
// Limit width.
if (new_frame_width > kMaxWidth) {
new_frame_height = new_frame_height * kMaxWidth / new_frame_width;
new_frame_width = kMaxWidth;
}
// Limit height.
if (new_frame_height > kMaxHeight) {
new_frame_width = new_frame_width * kMaxHeight / new_frame_height;
new_frame_height = kMaxHeight;
}
// Limit number of pixels.
if (new_frame_width * new_frame_height > kMaxPixels) {
// Compute new width such that width * height is less than maximum but
// maintains original captured frame aspect ratio.
new_frame_width = static_cast<int>(sqrtf(static_cast<float>(
kMaxPixels) * new_frame_width / new_frame_height));
new_frame_height = kMaxPixels / new_frame_width;
}
// Snap to a scale factor that is less than or equal to target pixels.
float scale = FindLowerScale(frame_width, frame_height,
new_frame_width * new_frame_height);
*scaled_width = static_cast<int>(frame_width * scale + .5f);
*scaled_height = static_cast<int>(frame_height * scale + .5f);
}
// Compute size to crop video frame to.
// If cropped_format_* is 0, return the frame_* size as is.
void ComputeCrop(int cropped_format_width,
int cropped_format_height,
int frame_width, int frame_height,
int pixel_width, int pixel_height,
int rotation,
int* cropped_width, int* cropped_height) {
ASSERT(cropped_format_width >= 0);
ASSERT(cropped_format_height >= 0);
ASSERT(frame_width > 0);
ASSERT(frame_height > 0);
ASSERT(pixel_width >= 0);
ASSERT(pixel_height >= 0);
ASSERT(rotation == 0 || rotation == 90 || rotation == 180 || rotation == 270);
ASSERT(cropped_width != NULL);
ASSERT(cropped_height != NULL);
if (!pixel_width) {
pixel_width = 1;
}
if (!pixel_height) {
pixel_height = 1;
}
// if cropped_format is 0x0 disable cropping.
if (!cropped_format_height) {
cropped_format_height = 1;
}
float frame_aspect = static_cast<float>(frame_width * pixel_width) /
static_cast<float>(frame_height * pixel_height);
float crop_aspect = static_cast<float>(cropped_format_width) /
static_cast<float>(cropped_format_height);
int new_frame_width = frame_width;
int new_frame_height = frame_height;
if (rotation == 90 || rotation == 270) {
frame_aspect = 1.0f / frame_aspect;
new_frame_width = frame_height;
new_frame_height = frame_width;
}
// kAspectThresh is the maximum aspect ratio difference that we'll accept
// for cropping. The value 1.33 is based on 4:3 being cropped to 16:9.
// Set to zero to disable cropping entirely.
// TODO(fbarchard): crop to multiple of 16 width for better performance.
const float kAspectThresh = 16.f / 9.f / (4.f / 3.f) + 0.01f; // 1.33
// Wide aspect - crop horizontally
if (frame_aspect > crop_aspect &&
frame_aspect < crop_aspect * kAspectThresh) {
// Round width down to multiple of 4 to avoid odd chroma width.
// Width a multiple of 4 allows a half size image to have chroma channel
// that avoids rounding errors. lmi and webrtc have odd width limitations.
new_frame_width = static_cast<int>((crop_aspect * frame_height *
pixel_height) / pixel_width + 0.5f) & ~3;
} else if (crop_aspect > frame_aspect &&
crop_aspect < frame_aspect * kAspectThresh) {
new_frame_height = static_cast<int>((frame_width * pixel_width) /
(crop_aspect * pixel_height) + 0.5f) & ~1;
}
*cropped_width = new_frame_width;
*cropped_height = new_frame_height;
if (rotation == 90 || rotation == 270) {
*cropped_width = new_frame_height;
*cropped_height = new_frame_width;
}
}
// The C++ standard requires a namespace-scope definition of static const
// integral types even when they are initialized in the declaration (see
// [class.static.data]/4), but MSVC with /Ze is non-conforming and treats that
// as a multiply defined symbol error. See Also:
// http://msdn.microsoft.com/en-us/library/34h23df8.aspx
#ifndef _MSC_EXTENSIONS
const int64 VideoFormat::kMinimumInterval; // Initialized in header.
#endif
std::string VideoFormat::ToString() const {
std::string fourcc_name = GetFourccName(fourcc) + " ";
for (std::string::const_iterator i = fourcc_name.begin();
i < fourcc_name.end(); ++i) {
// Test character is printable; Avoid isprint() which asserts on negatives.
if (*i < 32 || *i >= 127) {
fourcc_name = "";
break;
}
}
std::ostringstream ss;
ss << fourcc_name << width << "x" << height << "x" << IntervalToFps(interval);
return ss.str();
}
} // namespace cricket