AVAssetWriterInput目前不支持AVVideoScalingModeFit - IOS错误。

Question

我正在尝试使用AVAssetWriterInput来裁剪我在应用程序屏幕上看到的视频。这是我目前的配置。

NSDictionary *videoCleanApertureSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                            [NSNumber numberWithInt:320], AVVideoCleanApertureWidthKey,
                                            [NSNumber numberWithInt:480], AVVideoCleanApertureHeightKey,
                                            [NSNumber numberWithInt:10], AVVideoCleanApertureHorizontalOffsetKey,
                                            [NSNumber numberWithInt:10], AVVideoCleanApertureVerticalOffsetKey,
                                            nil];


NSDictionary *videoAspectRatioSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                          [NSNumber numberWithInt:3], AVVideoPixelAspectRatioHorizontalSpacingKey,
                                          [NSNumber numberWithInt:3],AVVideoPixelAspectRatioVerticalSpacingKey,
                                          nil];

NSDictionary *codecSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                               [NSNumber numberWithInt:960000], AVVideoAverageBitRateKey,
                               [NSNumber numberWithInt:1],AVVideoMaxKeyFrameIntervalKey,
                               videoCleanApertureSettings, AVVideoCleanApertureKey,
                               videoAspectRatioSettings, AVVideoPixelAspectRatioKey,
                               AVVideoProfileLevelH264BaselineAutoLevel, AVVideoProfileLevelKey,
                               nil];

NSDictionary *videoSettings = @{AVVideoCodecKey:AVVideoCodecH264,
                                AVVideoCompressionPropertiesKey:codecSettings,
                                AVVideoScalingModeKey:AVVideoScalingModeResizeAspectFill,
                                AVVideoWidthKey:[NSNumber numberWithInt:320],
                                AVVideoHeightKey:[NSNumber numberWithInt:480]};

_videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings];

我收到以下错误："AVAssetWriterInput目前不支持AVVideoScalingModeFit“

对于任何使用这个库的人来说，这是一个常见的错误，但是我找不到它的实际解决方案。我只是看到人们说：“我终于想出来了”，但没有解释。这个问题肯定与这一行有关："AVVideoScalingModeKey:AVVideoScalingModeResizeAspectFill，“，它告诉AVAssetWriter裁剪视频并保持高宽比。有人知道解决这个问题的办法吗？

Answer 1

就其本身而言，没有“解决办法”。这根本是不支持的。您将需要自己缩放视频帧使用核心图像或VTPixelTransferSession或任何适合您的管道。