legacyviewer_tools

Code to generate mosaics and videos from the Legacy Survey Sky Browser.

Example usage

First, generate a JSON containing one WCS dictionary for each frame:

python gen_framespec.py -c0 301.65071841 -6.12318614 28 -c1 301.65071841 -6.12318614 0.5 -n 600 --coordsys galactic --resolution 480p --layers decaps2[2] decaps2[1] decaps2[0] > musca_480p.json

Optionally, set a directory in which to store the cutouts downloaded from the Legacy Survey Sky Browser. The cutouts will be cached here, so that they do not have to be downloaded twice. This also means that the directory may fill up over time:

export CUTOUT_DIR="/path/to/cutout/directory/"

If CUTOUT_DIR is not set, then it defaults to cutouts/.

Then, feed the frame specification JSON to gen_video.py to generate the frames:

python3 gen_video.py \
    musca_480p.json \
    --img-outpattern frames/musca_gamma0.25_480p_frame{:05d}.png \
    --reproject-method interp \
    --momentum 0.95 \
    --gamma 0.25

Finally, turn these frames into a video, using ffmpeg:

ffmpeg -y -r 30 -i frames/musca_gamma0.25_480p_frame%05d.png \
    -c:v libx264 -crf 22 -pix_fmt yuv420p -r 30 \
    videos/musca_gamma0.25_480p.mp4