Rotate
If the camera was recording in "upside down" mode:
parallel -u 'echo {}; jpegtran -rotate 180 -perfect -copy all -outfile {}.tran {} && mv {}.tran {}' ::: *.jpg
Resize & crop
For the GoPro HD Hero 2:
For the Xiaomi Yi:
1 # 16 MP
2 # Crop top
3 find . -name '*jpg' -print0 | xargs -0 -P$(nproc) -n256 gm mogrify -chop 0x864 -resize 1920x1080
4 # Crop top at 4K
5 find . -name '*jpg' -print0 | xargs -0 -P$(nproc) -n256 gm mogrify -chop 0x864 -resize 3840x2160
6
7 # 13 MP
8 # Crop top
9 find . -name '*jpg' -print0 | xargs -0 -P$(nproc) -n256 gm mogrify -chop 0x774 -resize 1920x1080
10 # Crop top at 4K
11 find . -name '*jpg' -print0 | xargs -0 -P$(nproc) -n256 gm mogrify -chop 0x774 -resize 3840x2160
12
13 # Xiaomi Yi 4K
14 # 8M (native 4K mode)
15 find . -name '*jpg' -print0 | xargs -0 -P$(nproc) -n256 gm mogrify -resize 1920x1080
For A6500:
# Crop bottom, use high-quality resizing find . -name '*JPG' -print0 | xargs -0 -P$(nproc) -n256 gm mogrify -gravity South -chop 0x625 -resize 3840x2160 -filter Lanczos -unsharp
LDR tone mapping
parallel -u 'echo {}; ~/sys/tonemap/tonemapping ~/sys/tonemap/default.tnp {} {}.tonemapped && mv {}.tonemapped {}' ::: *.jpg
batch:
for i in $(ls); do (cd $i; parallel -u 'echo {}; ~/sys/tonemap/tonemapping ~/sys/tonemap/default.tnp {} {}.tonemapped && mv {}.tonemapped {}' ::: *.jpg); done;
Encode to video (WebM, MP4)
# Old mencoder line
mencoder mf://*.JPG -mf fps=15:type=jpg -ovc lavc -oac lavc -of lavf -lavfopts format=webm -lavcopts threads=4:acodec=vorbis:vcodec=libvpx -ffourcc VP80 -o $(basename $(pwd)).webm
# New MPV line, for VP9
# qmax appears to set video quality… lower number (e.g. qmax=25) is better quality, higher number (default is qmax=63) is less quality
mpv mf://*.jpg -mf-fps=15 -mf-type=jpeg --ovc=libvpx-vp9 -ovcopts qmax=30,threads=$(nproc) -o $(basename $(pwd)).vp9.webm
# MPV for x264
mpv mf://*.jpg -mf-fps=15 -mf-type=jpeg --ovc=libx264 --ovcopts threads=$(nproc) -o $(basename $(pwd)).mp4
# MPV for lossless x264
mpv mf://*.jpg -mf-fps=15 -mf-type=jpeg --ovc=libx264 --ovcopts preset=veryslow,qp=0,threads=$(nproc) -o $(basename $(pwd)).lossless.mp4
See https://github.com/Argon-/mpv-config/blob/master/encoding-profiles.conf for more mpv encoding profiles.
batch:
# use one of the commands from above COMMAND='' # make sure to use single quotes for i in $(ls); do (echo cd $i; echo $COMMAND; echo cd ../); done
Merge files
After placing all the WebM files in one directory, merge with:
f() { args=("$1"); shift; args+=("${@/#/+ }"); echo "${args[@]}"; }; echo mkvmerge $(f $(ls *webm))
or for MP4:
echo -n MP4Box ""; for i in $(ls *mp4); do echo -n -cat $i "" ; done; echo -new out.mp4
Interesting links
Open-source implementation of Microsoft's HyperLapse: willcrichton/hyperlapse: Open-source implementation of MSR Hyperlapse