Question

我正在尝试使用Brad Larson的框架作为参考，以获得一些基本的图像处理测试。到目前为止，我已经实现了棕褐色滤镜，它有点工作，问题是我得到一个处理过的图像和每个渲染周期的非处理图像（如果我将fps设置为1秒，第一个渲染，第二个不是，第三个是的，等等）。我花了几个小时似乎无法找到原因。

我有2个窗口，视频预览图层和glkview，我正在渲染我的缓冲区。

这是我的代码，基本上只是尝试合成前面提到的框架：

查看了Load方法：

- (void)viewDidLoad
{
    [super viewDidLoad];

    session = [[AVCaptureSession alloc] init];

    // Add inputs and outputs.
    if ([session canSetSessionPreset:AVCaptureSessionPreset640x480]) {
        session.sessionPreset = AVCaptureSessionPreset640x480;
    }
    else {
        // Handle the failure.
        NSLog(@"Cannot set session preset to 640x480");
    }

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    NSError *error = nil;
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];

    if (!input) {
        // Handle the error appropriately.
        NSLog(@"Could create input: %@", error);
    }

    if ([session canAddInput:input]) {
        [session addInput:input];
    }
    else {
        // Handle the failure.
        NSLog(@"Could not add input");
    }




    captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];

    [captureVideoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspect];

    [captureVideoPreviewLayer setBounds:videoLayer.layer.bounds];
    [captureVideoPreviewLayer setPosition:videoLayer.layer.position];

    [videoLayer.layer addSublayer:captureVideoPreviewLayer];

    [session startRunning];



    // OPENGL stuff


    self.imageView.context = [[GPUImageOpenGLESContext sharedImageProcessingOpenGLESContext] context];


    if ([self createFilterProgram]) {
        NSLog(@"Filter Program Created");
    }


    if ([self createOutputProgram]) {
        NSLog(@"Output Program Created");
    }

    if (CVOpenGLESTextureCacheCreate != NULL)
    {
        [GPUImageOpenGLESContext useImageProcessingContext];
        CVReturn err = CVOpenGLESTextureCacheCreate(kCFAllocatorDefault, NULL, (__bridge void *)[[GPUImageOpenGLESContext sharedImageProcessingOpenGLESContext] context], NULL, &coreVideoTextureCache);
        if (err) 
        {
            NSAssert(NO, @"Error at CVOpenGLESTextureCacheCreate %d");
        }
        else
            NSLog(@"Initial CVOpenGLESTextureCache created");

        // Need to remove the initially created texture
        if (outputTexture)
        {
            glDeleteTextures(1, &outputTexture);
            outputTexture = 0;
        }
    }

    // DATA OUTPUT
    dataOutput = [[AVCaptureVideoDataOutput alloc] init];

    if ([session canAddOutput:dataOutput]) {
        [session addOutput:dataOutput];

        dataOutput.videoSettings = 
        [NSDictionary dictionaryWithObject: [NSNumber numberWithInt:kCVPixelFormatType_32BGRA]
                                    forKey: (id)kCVPixelBufferPixelFormatTypeKey];

        AVCaptureConnection *connection = [dataOutput connectionWithMediaType:AVMediaTypeVideo];

        [connection setVideoMaxFrameDuration:CMTimeMake(1, 1)];
        [connection setVideoMinFrameDuration:CMTimeMake(1, 1)];

    }
    else {
        // Handle the failure.
        NSLog(@"Could not add output");
    }
    // DATA OUTPUT END

    //dispatch_queue_t queue = dispatch_queue_create("MyQueue", NULL);
    [dataOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
    //dispatch_release(queue);

}

以及视频捕获中的委托方法：

- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection 
{

    NSLog(@"Render");
    //CFAbsoluteTime startTime = CFAbsoluteTimeGetCurrent();
    CVImageBufferRef cameraFrame = CMSampleBufferGetImageBuffer(sampleBuffer);
    int bufferWidth = CVPixelBufferGetWidth(cameraFrame);
    int bufferHeight = CVPixelBufferGetHeight(cameraFrame);

    if (CVOpenGLESTextureCacheCreate != NULL)
    {
        NSLog(@"Not Null");
        CVPixelBufferLockBaseAddress(cameraFrame, 0);

        [GPUImageOpenGLESContext useImageProcessingContext];
        CVOpenGLESTextureRef texture = NULL;
        CVReturn err = CVOpenGLESTextureCacheCreateTextureFromImage(kCFAllocatorDefault, coreVideoTextureCache, cameraFrame, NULL, GL_TEXTURE_2D, GL_RGBA, bufferWidth, bufferHeight, GL_BGRA, GL_UNSIGNED_BYTE, 0, &texture);

        if (!texture || err) {
            NSLog(@"CVOpenGLESTextureCacheCreateTextureFromImage failed (error: %d)", err);  
            return;
        }

        outputTexture = CVOpenGLESTextureGetName(texture);
        glBindTexture(CVOpenGLESTextureGetTarget(texture), outputTexture);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);


        // "setInputSize" method

        CGSize sizeOfFBO = CGSizeMake(bufferWidth, bufferHeight);

        // "newFrameReady" method

        static const GLfloat squareVertices[] = {
            -1.0f, -1.0f,
            1.0f, -1.0f,
            -1.0f,  1.0f,
            1.0f,  1.0f,
        };

        static const GLfloat squareTextureCoordinates[] = {
            0.0f, 0.0f,
            1.0f, 0.0f,
            0.0f,  1.0f,
            1.0f,  1.0f,
        };

        [GPUImageOpenGLESContext useImageProcessingContext];

        // "setFilterFBO" method
        if (!filterFramebuffer)
        {
            NSLog(@"New Filter Frame buffer");
            glActiveTexture(GL_TEXTURE1);
            glGenFramebuffers(1, &filterFramebuffer);
            glBindFramebuffer(GL_FRAMEBUFFER, filterFramebuffer);

            NSLog(@"Filter size: %f, %f", sizeOfFBO.width, sizeOfFBO.height);

            glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8_OES, (int)sizeOfFBO.width, (int)sizeOfFBO.height);
            glBindTexture(GL_TEXTURE_2D, outputTexture);
            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (int)sizeOfFBO.width, (int)sizeOfFBO.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, outputTexture, 0);

            GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);

            NSAssert(status == GL_FRAMEBUFFER_COMPLETE, @"Incomplete filter FBO: %d", status);
        }

        glBindFramebuffer(GL_FRAMEBUFFER, filterFramebuffer);
        glViewport(0, 0, (int)sizeOfFBO.width, (int)sizeOfFBO.height);

        // END "setFilterFBO" method

        glUseProgram(filterProgram); // This Program MUST be the filter one 

        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glActiveTexture(GL_TEXTURE2);
        glBindTexture(GL_TEXTURE_2D, outputTexture);

        glUniform1i(uniforms[filterInputTextureUniform], 2);    

        glVertexAttribPointer(position, 2, GL_FLOAT, 0, 0, squareVertices);
        glVertexAttribPointer(inputTextureCoordinate, 2, GL_FLOAT, 0, 0, squareTextureCoordinates);

        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

        static const GLfloat squareVertices2[] = {
            -1.0f, -1.0f,
            1.0f, -1.0f,
            -1.0f,  1.0f,
            1.0f,  1.0f,
        };

        static const GLfloat textureCoordinates2[] = {
            0.0f, 1.0f,
            1.0f, 1.0f,
            0.0f, 0.0f,
            1.0f, 0.0f,
        };


        [GPUImageOpenGLESContext useImageProcessingContext];

        //[self setDisplayFramebuffer];
        if (!displayFramebuffer)
        {
            NSLog(@"New Display Frame buffer");
            glGenFramebuffers(1, &displayFramebuffer);
            glBindFramebuffer(GL_FRAMEBUFFER, displayFramebuffer);

            glGenRenderbuffers(1, &displayRenderbuffer);
            glBindRenderbuffer(GL_RENDERBUFFER, displayRenderbuffer);

            [[[GPUImageOpenGLESContext sharedImageProcessingOpenGLESContext] context] renderbufferStorage:GL_RENDERBUFFER fromDrawable:(CAEAGLLayer*)imageView.layer];

            glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_WIDTH, &backingWidth);
            glGetRenderbufferParameteriv(GL_RENDERBUFFER, GL_RENDERBUFFER_HEIGHT, &backingHeight);
            NSLog(@"Backing width: %d, height: %d", backingWidth, backingHeight);

            glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, displayRenderbuffer);

            GLuint framebufferCreationStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER);
            NSAssert(framebufferCreationStatus == GL_FRAMEBUFFER_COMPLETE, @"Failure with display framebuffer generation");
        }

        glBindFramebuffer(GL_FRAMEBUFFER, displayFramebuffer);

        glViewport(0, 0, backingWidth, backingHeight);

        glUseProgram(outputProgram);

        glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);


        glActiveTexture(GL_TEXTURE4);     
        glBindTexture(GL_TEXTURE_2D, outputTexture);
        glUniform1i(uniformsOutput[outputTextureUniform], 4);   

        glVertexAttribPointer(outputPosition, 2, GL_FLOAT, 0, 0, squareVertices2);
        glVertexAttribPointer(outputTextureCoordinate, 2, GL_FLOAT, 0, 0, textureCoordinates2);

        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

        glBindRenderbuffer(GL_RENDERBUFFER, displayRenderbuffer);
        [[GPUImageOpenGLESContext sharedImageProcessingOpenGLESContext] presentBufferForDisplay];        

        //glBindRenderbuffer(GL_RENDERBUFFER, 0);

        CVPixelBufferUnlockBaseAddress(cameraFrame, 0);

        glBindTexture(outputTexture, 0);

        // Flush the CVOpenGLESTexture cache and release the texture
        CVOpenGLESTextureCacheFlush(coreVideoTextureCache, 0);
        CFRelease(texture);
        outputTexture = 0;
    }

    else
        NSLog(@"No support for fast CVOpenGLESTextureCacheCreate");
}

这是Brad的原始框架（非常酷）http://www.sunsetlakesoftware.com/2012/02/12/introducing-gpuimage-framework

如果有人知道为什么会这样，我会很感激帮助。

到目前为止，我认为可能导致这种情况的原因是：

在循环期间渲染2次（因为它丢弃了它）每1秒发生一次，即使它确实发生在最后一次超快一个人会留下哪个是经过处理的一个）
启用或禁用OpenGL的状态（我认为可能是因为但无法找到哪里）
没有正确使用缓冲区（我使用相同的缓冲区变量对于这两个步骤，这可能会造成一些麻烦）
它可能与上下文有关（我相信上下文是所有东西都被绘制的地方，所以如果我正在研究glkview 上下文我可能会覆盖图片）

如果这些想法有误，请纠正我，这是我第一次尝试使用OpenGL进行处理

谢谢！

修改

正如Brad所建议的那样，我使用了OpenGL分析器，得到了以下结果：

对于优化OpenGL代码，这个工具确实很棒。

使用图像处理过滤视频时OpenGL的问题

0 个答案: