0

我正在从这样的 OpenGL 层生成 CVPixelBufferRef

- (CVPixelBufferRef) getGLPixelBuf {
    int s = 1;
    UIScreen * screen = [UIScreen mainScreen];
    if ([screen respondsToSelector:@selector(scale)]){
        s = (int)[screen scale];
    }
    const int w = self.frame.size.width/2;
    const int h = self.frame.size.height/2;
    const NSInteger my_data_length = 4 * w * h * s * s;
    // allocate array and read pixels into it.
    GLubyte * buffer = malloc(my_data_length);

    GLint readType;
    GLint readFormat;
    glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_TYPE, &readType);
    glGetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT, &readFormat);

    glReadPixels(0, 0, w * s, h * s, readFormat, readType, buffer);

    // gl renders "upside down" so swap top to bottom into new array.
    GLubyte * buffer2 = malloc(my_data_length);

    for(int y = 0; y < h*s; y++){
        memcpy(buffer2 + (h * s - 1 - y) * 4 * w * s, buffer + (4 * y * w * s), 4 * w * s);
    }

    free(buffer);
    CVPixelBufferRef pixel_buffer = NULL;
    CVPixelBufferCreateWithBytes (NULL, w * 2, h * 2, kCVPixelFormatType_32BGRA, buffer2 , 4 * w * s, NULL, 0, NULL, &pixel_buffer);
    free(buffer2);

    return pixel_buffer;
}

然后将该像素缓冲区传递给我的 AVAssetWriterInputPixelBufferAdaptor 在一个辅助类中，如下所示：

- (void)recordFrame {
    if([recorder isRecording]){
        CVPixelBufferRef pixelBuffer = [self getGLPixelBuf];
        CVPixelBufferLockBaseAddress(pixelBuffer, 0);

        [recorder appendPixelBuffer:pixelBuffer withPresentationTime:camera.lastSampleTime];

        CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
        CVPixelBufferRelease(pixelBuffer);
    }
}

但是在该助手类中，以下内容

- (BOOL)appendPixelBuffer:(CVPixelBufferRef)pixelBuffer withPresentationTime:(CMTime)presentationTime {
    if (writerInput.readyForMoreMediaData)     
        return [adaptor appendPixelBuffer:pixelBuffer withPresentationTime:presentationTime];  
    return NO;
}

当我调用 appendPixelBuffer 时会导致 EXC_BAD_ACCESS。我已启用 NSZombieEnabled 但它没有为我提供任何信息。记录器被初始化为与 OpenGL 层的背景高度和宽度相同的高度和宽度。适配器配置为 kCVPixelFormatType_32BGRA 像素格式以及像素缓冲区。

任何帮助表示赞赏！谢谢！

4

1 回答 1

0

将像素缓冲区附加到适配器时不要锁定像素缓冲区，并且方法返回的 pixel_buffer- (CVPixelBufferRef) getGLPixelBuf;不会保留，要 CVPixelBufferRelease(pixelBuffer);在- (void)recordFrame;方法中使用，您需要在从返回之前保留 pixel_buffer- (CVPixelBufferRef) getGLPixelBuf;

于 2014-06-23T09:09:55.783 回答