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/*
* Copyright 2017 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#import "RTCMTLNV12Renderer.h"
#import <Metal/Metal.h>
#import <MetalKit/MetalKit.h>
#import "RTCMTLRenderer+Private.h"
#import "base/RTCLogging.h"
#import "base/RTCVideoFrame.h"
#import "base/RTCVideoFrameBuffer.h"
#import "components/video_frame_buffer/RTCCVPixelBuffer.h"
#include "rtc_base/checks.h"
static NSString *const shaderSource = MTL_STRINGIFY(
using namespace metal;
typedef struct {
packed_float2 position;
packed_float2 texcoord;
} Vertex;
typedef struct {
float4 position[[position]];
float2 texcoord;
} Varyings;
vertex Varyings vertexPassthrough(constant Vertex *verticies[[buffer(0)]],
unsigned int vid[[vertex_id]]) {
Varyings out;
constant Vertex &v = verticies[vid];
out.position = float4(float2(v.position), 0.0, 1.0);
out.texcoord = v.texcoord;
return out;
}
// Receiving YCrCb textures.
fragment half4 fragmentColorConversion(
Varyings in[[stage_in]],
texture2d<float, access::sample> textureY[[texture(0)]],
texture2d<float, access::sample> textureCbCr[[texture(1)]]) {
constexpr sampler s(address::clamp_to_edge, filter::linear);
float y;
float2 uv;
y = textureY.sample(s, in.texcoord).r;
uv = textureCbCr.sample(s, in.texcoord).rg - float2(0.5, 0.5);
float4 out = float4(y + 1.403 * uv.y, y - 0.344 * uv.x - 0.714 * uv.y, y + 1.770 * uv.x, 1.0);
return half4(out);
});
@implementation RTCMTLNV12Renderer {
// Textures.
CVMetalTextureCacheRef _textureCache;
id<MTLTexture> _yTexture;
id<MTLTexture> _CrCbTexture;
}
- (BOOL)addRenderingDestination:(__kindof MTKView *)view {
if ([super addRenderingDestination:view]) {
return [self initializeTextureCache];
}
return NO;
}
- (BOOL)initializeTextureCache {
CVReturn status = CVMetalTextureCacheCreate(kCFAllocatorDefault, nil, [self currentMetalDevice],
nil, &_textureCache);
if (status != kCVReturnSuccess) {
RTCLogError(@"Metal: Failed to initialize metal texture cache. Return status is %d", status);
return NO;
}
return YES;
}
- (NSString *)shaderSource {
return shaderSource;
}
- (void)getWidth:(nonnull int *)width
height:(nonnull int *)height
cropWidth:(nonnull int *)cropWidth
cropHeight:(nonnull int *)cropHeight
cropX:(nonnull int *)cropX
cropY:(nonnull int *)cropY
ofFrame:(nonnull RTC_OBJC_TYPE(RTCVideoFrame) *)frame {
RTC_OBJC_TYPE(RTCCVPixelBuffer) *pixelBuffer = (RTC_OBJC_TYPE(RTCCVPixelBuffer) *)frame.buffer;
*width = CVPixelBufferGetWidth(pixelBuffer.pixelBuffer);
*height = CVPixelBufferGetHeight(pixelBuffer.pixelBuffer);
*cropWidth = pixelBuffer.cropWidth;
*cropHeight = pixelBuffer.cropHeight;
*cropX = pixelBuffer.cropX;
*cropY = pixelBuffer.cropY;
}
- (BOOL)setupTexturesForFrame:(nonnull RTC_OBJC_TYPE(RTCVideoFrame) *)frame {
RTC_DCHECK([frame.buffer isKindOfClass:[RTC_OBJC_TYPE(RTCCVPixelBuffer) class]]);
if (![super setupTexturesForFrame:frame]) {
return NO;
}
CVPixelBufferRef pixelBuffer = ((RTC_OBJC_TYPE(RTCCVPixelBuffer) *)frame.buffer).pixelBuffer;
id<MTLTexture> lumaTexture = nil;
id<MTLTexture> chromaTexture = nil;
CVMetalTextureRef outTexture = nullptr;
// Luma (y) texture.
int lumaWidth = CVPixelBufferGetWidthOfPlane(pixelBuffer, 0);
int lumaHeight = CVPixelBufferGetHeightOfPlane(pixelBuffer, 0);
int indexPlane = 0;
CVReturn result = CVMetalTextureCacheCreateTextureFromImage(
kCFAllocatorDefault, _textureCache, pixelBuffer, nil, MTLPixelFormatR8Unorm, lumaWidth,
lumaHeight, indexPlane, &outTexture);
if (result == kCVReturnSuccess) {
lumaTexture = CVMetalTextureGetTexture(outTexture);
}
// Same as CFRelease except it can be passed NULL without crashing.
CVBufferRelease(outTexture);
outTexture = nullptr;
// Chroma (CrCb) texture.
indexPlane = 1;
result = CVMetalTextureCacheCreateTextureFromImage(
kCFAllocatorDefault, _textureCache, pixelBuffer, nil, MTLPixelFormatRG8Unorm, lumaWidth / 2,
lumaHeight / 2, indexPlane, &outTexture);
if (result == kCVReturnSuccess) {
chromaTexture = CVMetalTextureGetTexture(outTexture);
}
CVBufferRelease(outTexture);
if (lumaTexture != nil && chromaTexture != nil) {
_yTexture = lumaTexture;
_CrCbTexture = chromaTexture;
return YES;
}
return NO;
}
- (void)uploadTexturesToRenderEncoder:(id<MTLRenderCommandEncoder>)renderEncoder {
[renderEncoder setFragmentTexture:_yTexture atIndex:0];
[renderEncoder setFragmentTexture:_CrCbTexture atIndex:1];
}
- (void)dealloc {
if (_textureCache) {
CFRelease(_textureCache);
}
}
@end