![]() ![]() ![]() There are many cases where the size of the resulting file is the same as the original. In other words, the quality is preserved while reducing media size. A lossless compression refers to reducing the media sizes of a video without appreciable or significant loss of information. Thus, it is vital to figure out first what this compression is before we offer solutions. Many users are still confused, and it may be unclear what lossless video compression is. Helpful Online Lossless Video Compression Tool Superb Lossless Video Compression Software That said, if your slightly upsampled file is significantly larger (in bytes) than the original, it suggests it was coded with a very low QP value, so you probably wouldn't lose much by going up and down. If you want a smaller file, then you'll be operating in a "lossy" mode with some quantization/rate control. A traditional video codec achieves efficiency through lossy compression, and by demanding lossless you've prohibited it from using a large number of the techniques it would normally use. However, the file that results will be large. If you want something "like zip", then this is the answer. You could do that losslessly with ffmpeg using -crf 0. Furthermore, encoding the upsampled video has introduced some distortion which will also be in the downsampled video.īut for the sake of argument, let's assume you've got downsampled video at the desired resolution which you're OK with. In reality, you probably don't know which filter was used for upsampling, and most likely the filter you use for downsampling won't be the exact inverse. If you knew which upsampling filter was used, in theory the inverse filter could be applied and exactly undo the upsampling. There is no such thing as "good pixels" and "extra pixels". When video is scaled, an upsampling filter is used which modifies all pixels. The short answer is no, you cannot do it completely losslessly. I can't understand what's not possible about this. Lossy to lossless shouldn't result in quality loss. In a few words, I want to take every frame, downscale it by lowering the number of pixels (which does not result in any quality loss whatsoever because the video is upscaled), then compress the result to a lossless codec. I do not mind the output codec being different. ![]() Can't that process be done for my upscaled video? (along with losslessly compressing every frame). Now I can easily compress that to a 2x2 image and lose nothing at all, I can take pixels of the same color and group them into one, thus having less information. Of course it can't magically know which pixels to get rid of, but that can be calculated, can't it? Say I have a 4x4 image, composed of 4 colors in a 2x2 grid. Can I do this completely losslessly?Įdit: maybe my wording was unclear. The best result I've got so far is like this:įfmpeg -i video.mp4 -vcodec libx264 -crf 23 -acodec copy -vf "scale=1024:576" output.mp4, but there is a slight quality loss. Can I compress the video using ffmpeg back to 576p and that same size, with no quality loss? In other words, can I get rid of the extra pixels without harming the good pixels? And not just the numbers are different, there actually are more pixels, I know this because I have the same video in that resolution, and it is around 70 MB, the quality is the same or arguably better. However the video is upscaled, the actual quality is 1024x576. I cannot seem to find a good answer to this. ![]()
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