Transform

Transform is a video filter that transforms 360 video in equirectangular projection into a cubemap projection

Building

Transform is implemented as an ffmpeg video filter. To build Transform, follow these steps:

1. Checkout the source for ffmpeg.
2. Copy vf_transform.c to the libavfilter subdirectory in ffmpeg source.
3. Edit libavfilter/allfilters.c and register the filter by adding the line: REGISTER_FILTER(TRANSFORM, transform, vf); in the video filter registration section.
4. Edit libavfilter/Makefile and add the filter to adding the line: OBJS-$(CONFIG_TRANSFORM_FILTER) += vf_transform.o in the filter section.
5. Configure and build ffmpeg as usual.

Running

Check out the options for the filter by running ffmpeg -h filter=transform.

A typical example looks something like:

ffmpeg -i input.mp4 \
    -vf transform="input_stereo_format=MONO
    :w_subdivisions=4
    :h_subdivisions=4
    :max_cube_edge_length=512" \
    output.mp4