used to be 9-15 apart, then 9-30, and now, with partial I-frames on some drones, up to 120 frames in between actual complete frames. H.264 is encoded as complete or I-frames that are complete but compressed, and in-between those. H.264 files are tricky to do this as only between every 9-30 frames can you actually 'cut' with only a re-wrap. Search with something like 'cutting and re-wrapping video files without re-encoding', and you'll get results for a number of different apps, YouTube vids on doing it, that sort of thing. The following frame sizes (in pixels) are in the 16:9 ratio and each dimension is divisible by 16.There are some apps out there, some free, some paid, that can do trimming & re-wrapping. The -tag:v hvc1 option is the key to making the resulting video compatible with the Apple QuickTime player. If the source audio is already in a reasonable format and you just want to re-encode the video, then -c:a copy can be used to exactly copy the audio without re-encoding. AAC is chosen by default for mp4 files, so it may not be necessary to specify the audio settings. In this example we’re setting the audio codec ( -c:a aac) and bitrate ( -b:a 128k). Changing the crf setting by 6 in either direction will roughly double/halve the video bitrate. The range is between 0 and 51, but the extreme values aren’t much use. The constant rate factor (crf) defaults to 28 for H265 encoding, so the -crf 28 option in this command is redundant, but you can make the number lower (for higher quality) or higher (for lower quality). The -c:v libx265 sets the video codec to H265. Convert a collection of 4k videos to a smaller sizeįor f in *.MP4 do ffmpeg -i '$f' -vf scale=1920:-1 -pix_fmt yuv420p -crf 22 -metadata artist='My Name' '$sml.mp4' done Generate Apple-compatible HEVC H265 encodingįfmpeg -i input.mov -c:v libx265 -crf 28 -c:a aac -b:a 128k -tag:v hvc1 output.mp4

It has useful defaults for quality and video/audio codecs to use, so you tend to get what you expect for well-defined file formats.

Basic video conversionįFmpeg can be very simple to use. Search Home → Photo & video → FFmpeg recipesįFmpeg is an open source command line tool to convert multimedia files between formats and optionally apply a wide range of filters and effects.

Ffmpeg crop video without re encoding