如何绘制到CIImage
(或者可能进入CVPixelBuffer
,但我想更容易将文字添加到CIImage
)? 不是UIImage
我使用AVAssetWriter
和CMSampleBuffer
(来自视频,音频输入)录制视频(.mp4文件)。在录制时我想在视频帧上添加文字,我已经将CMSampleBuffer
转换为CIImage
,现在我需要以某种方式将文字添加到CIImage
并转换回CVPixelBuffer
。我没有在Swift中找到任何简单的例子如何向CIImage
添加(绘制)文本或添加任何其他内容(如行,rects,而不仅仅是文本)。
/// encode video buffer
func appendVideoSampleBuffer(_ sampleBuffer: CMSampleBuffer) {
// before encoding video frames into a file I would like process it
// 1. convert CMSampleBuffer to ciImage
let cvPixelBuffer: CVPixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)!
let ciimage : CIImage = CIImage(cvPixelBuffer: cvPixelBuffer)
// 2. do something with CIImage
// 3. convert CIImage back to CMSampleBuffer
let sampleBufferWithText == ...
appendSampleBuffer(sampleBufferWithText, ofMediaType: AVMediaType.video.rawValue)
}
/// encode audio buffer
func appendAudioSampleBuffer(_ sampleBuffer: CMSampleBuffer) {
appendSampleBuffer(sampleBuffer, ofMediaType: AVMediaType.audio.rawValue)
}