[FFmpeg-devel] [PATCH 1/3 v2] lavu: Add AVSphericalMapping type and frame side data

[Vittorio Giovara]

On Tue, Nov 15, 2016 at 8:52 PM, James Almer <jamrial at gmail.com> wrote:
> On 11/15/2016 10:39 PM, Michael Niedermayer wrote:
>> On Tue, Nov 15, 2016 at 11:56:48AM -0500, Vittorio Giovara wrote:
>> [...]
>>> +/**
>>> + * This structure describes how to handle spherical videos, outlining
>>> + * information about projection, initial layout, and any other view modifier.
>>> + *
>>> + * @note The struct must be allocated with av_spherical_alloc() and
>>> + *       its size is not a part of the public ABI.
>>> + */
>>> +typedef struct AVSphericalMapping {
>>> +    /**
>>> +     * Projection type.
>>> +     */
>>> +    enum AVSphericalProjection projection;
>>> +
>>> +    /**
>>> +     * @name Initial orientation
>>> +     * @{
>>> +     * These fields represent the pose values that measure the rotation
>>> +     * transformation (in degrees) to be applied to the projection.
>>
>>> +     * They are exported as 16.16 fixed point.
>>
>> why waste 7 bits of precission ?
>
> 16.16 seems to be part of the spec
>
> https://github.com/google/spatial-media/blob/master/docs/spherical-video-v2-rfc.md

Correct, there is no point in adding more precision that the
underlying layer can withhold.
-- 
Vittorio