TOOL » FFMPEG

Speed

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Reference:trac.ffmpeg.org

Lossless video speed manipulation ​

Consider a 30 FPS video, and we want to convert it to 60 FPS losslessy.

First convert to raw bitstream format.

shell
ffmpeg -i input.mp4 -map 0:v -an -c:v copy -bsf:v h264_mp4toannexb raw.h264
ffmpeg -i input.mp4 -map 0:v -an -c:v copy -bsf:v hevc_mp4toannexb raw.h265

Video only: Regenerate the video with new timestamps.

shell
ffmpeg -fflags +genpts -r 60 -i raw.h264 -c:v copy output.mp4

Video + Audio: Regenerate the video with the audio stream speed also changed:

shell
ffmpeg -fflags +genpts -r 60 -i raw.h264 -i input.mp4 -map 0:v -c:v copy -map 1:a -af atempo=2 -movflags faststart output.mp4

Audio speed manipulation ​

Valid atempo values are between 0.5 and 100.

Example of doubling the speed:

shell
ffmpeg -i input.flac -af atempo=2.0 output.flac