ApsaraVideo Live：自訂視頻渲染

2.3 處理幀

buffer回調的處理：

- (bool)handleBeautyProcessBuffer:(CVPixelBufferRef)pixelBufferRef {
    if (!self.beautyEngine) {
        [self initBeautyEngine];
    }
    if (self.beautyEngine && pixelBufferRef)
    {
        QEPixelBufferData *bufferData = [QEPixelBufferData new];
        bufferData.bufferIn = pixelBufferRef;
        bufferData.bufferOut = pixelBufferRef;
        // 對pixelBuffer進行影像處理，輸出處理後的buffer
        kQueenResultCode resultCode = [self.beautyEngine processPixelBuffer:bufferData];//執行此方法的線程需要始終是同一條線程
        if (resultCode == kQueenResultCodeOK && bufferData.bufferOut)
        {
            return YES;
        }
    }
    return NO;
}

紋理回調的處理：

- (bool)handleBeautyProcessTexture:(int)textureID withWidth:(int)width withHeight:(int)height {
    // 見下文純紋理處理模式
}

3 建立美顏處理器

- (void)initBeautyEngine:(BOOL)processBuffer
{
    if (self.beautyEngine != nil) {
        return;
    }
    // 初始化引擎配置資訊對象
    QueenEngineConfigInfo *configInfo = [QueenEngineConfigInfo new];

    // 設定是否自動化佈建圖片旋轉角度，如裝置鎖屏，並且預設映像採集來自網路攝影機的話可以設定自動化佈建圖片旋轉角度
    configInfo.autoSettingImgAngle = YES;
    
    configInfo.runOnCustomThread = processBuffer ? NO : YES; // 紋理調用時，為YES，buffer調用時，為NO，NO表示不運行在當前調用者線程，內部會建立一個新線程
    configInfo.withContext = processBuffer ? YES : NO;        // 紋理調用時，為NO，buffer調用時，為YES，YES表示需要內部建立glContext
    
    // 調試介面，開啟美顏sdk日誌功能
    // configInfo.enableDebugLog = YES;

    // 引擎初始化
    self.beautyEngine = [[QueenEngine alloc] initWithConfigInfo:configInfo];
    
    ...
    // 其他保持相同
}

4 處理幀

- (int)handleBeautyProcessTexture:(int)textureID withWidth:(int)width withHeight:(int)height {
    if (!self.beautyEngine) {
        [self initBeautyEngine:NO];
    }

    // 進階美顏功能需要臉部偵測演算法，因此需要額外傳入bufData。
    // 如果僅開基礎美顏，則不用調用updateInputDataAndRunAlg方法。
    uint8_t* bufData = [self extractI420DataFromPixelBuffer:videoSample.pixelBuffer];
    [self.beautyEngine updateInputDataAndRunAlg:bufData
                                            withImgFormat:kQueenImageFormatNV12
                                            withWidth:width
                                            withHeight:height
                                             withStride:0
                                         withInputAngle:0
                                        withOutputAngle:0
                                           withFlipAxis:0];
    free(bufData);
    
    QETextureData* textureData = [[QETextureData alloc] init];
    textureData.inputTextureID = textureID;
    textureData.width = width;
    textureData.height = height;
    kQueenResultCode result = [self.beautyEngine processTexture:textureData];
    if (result != kQueenResultCodeOK)
    {
        return textureID;
    }
    return textureData.outputTextureID;
}

紋理模式處理時，為提升整體效能，避免從紋理中再次提取buffer資料，因此需要應用程式層，將buffer提取出來傳遞給美顏SDK，調用介面。

以下為buffer提取範例程式碼：

-(uint8_t *)extractI420DataFromPixelBuffer:(CVPixelBufferRef) pixelBuffer {
    uint8_t *bufData = nil;
    // 擷取格式資訊
    OSType pixelFormat = CVPixelBufferGetPixelFormatType(pixelBuffer);
    size_t bufWidth = CVPixelBufferGetWidth(pixelBuffer);
    size_t bufHeight = CVPixelBufferGetHeight(pixelBuffer);
        
    // 鎖定buffer
    CVPixelBufferLockBaseAddress(pixelBuffer, kCVPixelBufferLock_ReadOnly);
    
    if (CVPixelBufferIsPlanar(pixelBuffer)) {
        if (pixelFormat == kCVPixelFormatType_420YpCbCr8BiPlanarFullRange) {
            uint8_t *yPlane = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
            uint8_t *uvPlane = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1);

            size_t yStride = CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
            size_t uvStride = CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 1);

            size_t width = CVPixelBufferGetWidth(pixelBuffer);
            size_t height = CVPixelBufferGetHeight(pixelBuffer);
            // 分配標準NV12大小（無padding）
            size_t bufDataSize = width * height * 3 / 2;
            bufData = (uint8_t *)malloc(bufDataSize);
            // 逐行拷貝Y平面（去除stride padding）
            for (size_t i = 0; i < height; i++) {
                memcpy(bufData + i * width, yPlane + i * yStride, width);
            }
            // 逐行拷貝UV平面
            for (size_t i = 0; i < height / 2; i++) {
                memcpy(bufData + width * height + i * width,
                       uvPlane + i * uvStride,
                       width);
            }
        }
        
    } else {
        // 打包格式（如BGRA）
        void *baseAddress = CVPixelBufferGetBaseAddress(pixelBuffer);
        size_t dataSize = CVPixelBufferGetDataSize(pixelBuffer);
        // 處理baseAddress
        bufData = (uint8_t *)malloc(dataSize);
        memcpy(bufData, baseAddress, dataSize);
    }
    CVPixelBufferUnlockBaseAddress(pixelBuffer, kCVPixelBufferLock_ReadOnly);

    return bufData;
}