![]() For compatibility reasons old values can be specified as numbers. qmax – the maximum quantizer (default 63, range qmin–63) qmin – the minimum quantizer (default 4, range 0–63) (it prevents you from getting certain frames in your video which are of absolutely dreadful quality where everything is blocky as fuck, basically). So the overall video quality will be more consistent I believe the -qmax option prevents the quality from dropping below a certain level for any given frame, qmin, -qmax: Tells ffmpeg what "quantization parameter" to use when assigning quality.ĭon't worry if you don't know what a quantization parameter is, because neither do I.Īll I know is that lower numbers = better quality. If you are looking for a smaller file size, consider leaving this out Only use this option if you desire a constant bitrate, which will produce a higher quality file. Ideally it should be used with the 2-pass encoding method. This is a way of achieving high quality while still retaining control over the filesize. When -b:v is used without -crf, the value of -b:v is a target bitrate, but when -b:v and -crf are used together, -b:v becomes a maximum bitrate. Constrained quality mode will try to achieve a certain level of quality, but without going over a specified bitrate level. To use constrained quality mode, you must specify both a CRF value (e.g.This can result in very large file sizes, so is generally not suitable for making webms intended for imageboards which typically have a file size limit of 10MB or less constant level of quality, using whatever bitrate is necessary to achieve that level of quality. Constant quality mode tries to achieve a. If you just remove the "-b:v" option altogether, ffmpeg will simply fall back on the default bitrate (256K, I think), which will result in a constrained quality encode with extremely poor quality. To use constant quality mode, you MUST use a value of "0" when specifying the video bitrate (-b:v 0).Must be from 4-63 in VP8, or 0-63 in VP9. Libvpx-vp9 is the VP9 video encoder for WebM Select an encoder or a decoder for one or more streams. r Set frame rate (Hz value, fraction or abbreviation). ‘ median-cut’ is the median cut algorithm described by Heckbert.‘ blend-diversity’ is a modification of this: some color values are blended from groups of existing colors.‘ diversity’, the default, is xv(1)’s diversity algorithm, which uses a strict subset of the existing colors and generally produces good results.The special filename ‘-’ means the standard output.ĭetermine how a smaller colormap is chosen. This can be used to shrink output GIFs or eliminate any local color tables. ![]() ![]() Reduce the number of distinct colors in each output GIF to num or less. Lossiness determines how many artifacts are allowed higher values can result in smaller file sizes, but cause more artifacts. Level determines how much optimization is done higher levels take longer, but may have better results.Īlter image colors to shrink output file size at the cost of artifacts and noise. Optimize output GIF animations for space. (GIFs read from the standard input are written to the standard output.) batch, -b Modify each GIF input in place by reading and writing to the same filename.
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