# FFMPEG

## AVI to MP4
ffmpeg -i input.avi -c:v libx264 -crf 19 -preset slow -c:a aac -strict experimental -b:a 192k -ac 2 out.mp4
# or
ffmpeg -i input.avi -c:v libx264 -crf 19 -preset slow -c:a libfaac -b:a 192k -ac 2 out.mp4

## AVI to HEVCMP4
ffmpeg -i input.avi -c:v libx265 -crf 21 -c:a aac -c:s mov_text -f mp4 -pix_fmt yuv420p -tag:v hvc1 -movflags faststart out.mp4

## MKV to MP4
ffmpeg -i input.mkv -codec copy output.mp4

## to remove audio
- `-an`
## reduce file size
ffmpeg -vaapi_device /dev/dri/renderD129 -i interstellar.mkv -vf 'format=nv12,hwupload' -c:v hevc_vaapi -crf 23 -c:a aac -f mp4 -tag:v hvc1 Interstellar2160p.mp4

## save a frame
ffmpeg -ss 01:23:45 -i input -vframes 1 -q:v 2 output.jpg

## convert images to video
### 1 frame per image
ffmpeg -i calibrate%d.jpg -c:v libx264 -pix_fmt yuv420p calibrate.mp4
### each image shown for 5 secs at 25fps at 125 frames per image
ffmpeg -framerate 1/5 -i calibrate%d.jpg -c:v libx264 -vf fps=25 -pix_fmt yuv420p calibrate.mp4
### convert images to gif giving only 1/5th of the image to a second
./ffmpeg.exe -f image2 -r 1/5 -i assets/calibrate%d.jpg assets/calibrate.gif

## scale video
ffmpeg -i input.avi -filter:v scale=720:-1 -c:a copy output.mkv

## crop video w:h:x:y
./ffmpeg.exe -i assets/clock.mp4 -c:v libx264 -pix_fmt yuv420p -filter:v "crop=300:300:0:0,fps=20" assets/clock300x300r20.mp4
### by time
-ss 00:00:07.8 -to 00:02:00

## record screens
```
ffmpeg -video_size 800x600 -framerate 25 -f x11grab \
-i :0.0+<xinit>,<yinit> screenreocrd1.mp4
```

## create live m3u8 stream
ffmpeg -video_size 800x600 -framerate 15 -f x11grab -i :0.0+5,60 -f pulse -i default -c:v libx264 -pix_fmt yuv420p -profile:v baseline -level 3.0 -b:v 1000k -preset ultrafast -tune zerolatency -keyint_min 45 -g 45 -sc_threshold 0 -c:a aac -b:a 96k -f hls -hls_time 3 -hls_list_size 10 -hls_segment_type mpegts -hls_flags program_date_time -hls_segment_filename /mnt/ventoy/workspace/WWW-development/files/user/necktwi/doom/stream%04d.ts /mnt/ventoy/workspace/WWW-development/files/user/necktwi/doom/stream.m3u8

## list supported formats
ffmpeg -formats
ffmpeg -codecs
ffmpeg -encoders
ffmpeg -decoders
ffmpeg -h encoder=h264
ffmpeg -hwaccels

## build on qnx
export SYSROOT=/c/qnx700/target/qnx7/aarch64le
export TOOLCHAIN=/c/qnx700/host/win64/x86_64

../configure --disable-x86asm --prefix=./install --target-os=qnx --cross-prefix="$TOOLCHAIN/usr/bin/aarch64-unknown-nto-qnx7.0.0-" --arch=aarch64 --sysroot=$SYSROOT --enable-shared --enable-runtime-cpudetect --enable-gpl --enable-pthreads --enable-small --enable-cross-compile --enable-static --enable-nonfree --extra-cflags="-I$TOOLCHAIN/usr/lib/gcc/aarch64-unknown-nto-qnx7.0.0/5.4.0/include" --nm=$TOOLCHAIN/usr/bin/aarch64-unknown-nto-qnx7.0.0-nm

## yt-dlp