ios - AVAssetWriter 如何创建无压缩的 mov 视频？

Question

我正在用一组图像创建视频。我的工作目的是创建一个没有压缩的 .mov 视频。我在开发人员库中看到它存在一个键“AVVideoCompressionPropertiesKey”，但我不知道如何使用此键指定不压缩。

你能帮帮我吗？

这是我的示例代码:

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

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


NSDictionary *videoOutputSettings = [NSDictionary dictionaryWithObjectsAndKeys:AVVideoCodecH264, AVVideoCodecKey,codecSettings,AVVideoCompressionPropertiesKey, [NSNumber numberWithInt:size.width], AVVideoWidthKey,
                                     [NSNumber numberWithInt:size.height], AVVideoHeightKey, nil];

self.videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoOutputSettings];

Answer 1

尝试使用 AVVideoCodecJPEG 并将 AVVideoQualityKey 值设置为 NSNumber 1.0。另一种方法是指定 H264，将比特率设置为非常非常高的值，并将关键帧间隔指定为 1(即所有关键帧)。