[FFmpeg-devel] [PATCH] lavu: Add AVSphericalMapping type and frame side data

[Vittorio Giovara]

On Tue, Dec 6, 2016 at 10:46 AM, Vittorio Giovara
<vittorio.giovara at gmail.com> wrote:
> While no decoder currently exports spherical information, this type
> represents a frame property that has to be passed through from container
> to frames.
>
> Signed-off-by: Vittorio Giovara <vittorio.giovara at gmail.com>
> ---
> +    /**
> +     * @name Initial orientation
> +     * @{
> +     * There fields describe additional rotations applied to the sphere after
> +     * the video frame is mapped onto it. The sphere is rotated around the
> +     * viewer, who remains stationary. The order of transformation is always
> +     * yaw, followed by pitch, and finally by roll.
> +     *
> +     * The coordinate system matches the one defined in OpenGL, where the
> +     * forward vector (z) is coming out of screen, and it is equivalent to
> +     * a rotation matrix of R = r_y(yaw) * r_x(pitch) * r_z(roll).
> +     *
> +     * A positive yaw points the viewer towards the left.
> +     * A positive pitch points the viewer downwards.
> +     * A positive roll tilts the viewer to the right.

One more iteration of this description, hopefully final:
     * A positive yaw rotates the portion of the sphere in front of the viewer
     * toward their right. A positive pitch rotates the portion of the sphere
     * in front of the viewer upwards. A positive roll tilts the portion of
     * the sphere in front of the viewer to the viewer's right.
Unless objections I'll push the set in the next few days.
Please CC.
-- 
Vittorio