To understand ghost frames you have to understand a little bit about how compressed video is stored. In order to save memory, rather than storing every video frame completely, compressed video formats store only some of the frames completely- these are called keyframes. The rest of the frames, the encoder codec only saves information on the difference between the frame and the keyframe before and after, so in order to reconstitute these frames the decoder codec looks at the keyframe before, looks at the keyframe after, and looks at the information on how the frame it's reconstituting differs from both and uses that to recreate the frame.
When you're in your editor, if you cut at a keyframe, the editor is usually happy, because it has complete information about what the frame looks like, but if you cut in between keyframes, the editor sometimes has trouble deciding which frame to show, and this produces ghost frames.
More sophisticated editing programs usually are better at handling this, and will give you more tools to recognize what kind of frame you're cutting at, but the best way to deal with this is to convert your video from a compressed video format to either a fully uncompressed (or 'lossless') format, or to what's called an intermediate or editing format. These record more information about each frame so the editor is less likely to get caught up by a frame between keyframes. The tradeoff is that lossless and intermediate formats take up (a lot) more hard drive space, and doing the conversions takes time and sometimes thought.
no subject
Date: 2017-05-07 11:17 pm (UTC)When you're in your editor, if you cut at a keyframe, the editor is usually happy, because it has complete information about what the frame looks like, but if you cut in between keyframes, the editor sometimes has trouble deciding which frame to show, and this produces ghost frames.
More sophisticated editing programs usually are better at handling this, and will give you more tools to recognize what kind of frame you're cutting at, but the best way to deal with this is to convert your video from a compressed video format to either a fully uncompressed (or 'lossless') format, or to what's called an intermediate or editing format. These record more information about each frame so the editor is less likely to get caught up by a frame between keyframes. The tradeoff is that lossless and intermediate formats take up (a lot) more hard drive space, and doing the conversions takes time and sometimes thought.