ffmpeg/libavutil/spherical.c
Andreas Rheinhardt 514ee8770d avutil/spherical: Use av_strstart instead of strncmp
It makes the intent clearer and avoids calculating the length
separately.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2021-02-28 17:14:21 +01:00

80 lines
2.7 KiB
C

/*
* Copyright (c) 2016 Vittorio Giovara <vittorio.giovara@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avstring.h"
#include "mem.h"
#include "spherical.h"
AVSphericalMapping *av_spherical_alloc(size_t *size)
{
AVSphericalMapping *spherical = av_mallocz(sizeof(AVSphericalMapping));
if (!spherical)
return NULL;
if (size)
*size = sizeof(*spherical);
return spherical;
}
void av_spherical_tile_bounds(const AVSphericalMapping *map,
size_t width, size_t height,
size_t *left, size_t *top,
size_t *right, size_t *bottom)
{
/* conversion from 0.32 coordinates to pixels */
uint64_t orig_width = (uint64_t) width * UINT32_MAX /
(UINT32_MAX - map->bound_right - map->bound_left);
uint64_t orig_height = (uint64_t) height * UINT32_MAX /
(UINT32_MAX - map->bound_bottom - map->bound_top);
/* add a (UINT32_MAX - 1) to round up integer division */
*left = (orig_width * map->bound_left + UINT32_MAX - 1) / UINT32_MAX;
*top = (orig_height * map->bound_top + UINT32_MAX - 1) / UINT32_MAX;
*right = orig_width - width - *left;
*bottom = orig_height - height - *top;
}
static const char *const spherical_projection_names[] = {
[AV_SPHERICAL_EQUIRECTANGULAR] = "equirectangular",
[AV_SPHERICAL_CUBEMAP] = "cubemap",
[AV_SPHERICAL_EQUIRECTANGULAR_TILE] = "tiled equirectangular",
};
const char *av_spherical_projection_name(enum AVSphericalProjection projection)
{
if ((unsigned)projection >= FF_ARRAY_ELEMS(spherical_projection_names))
return "unknown";
return spherical_projection_names[projection];
}
int av_spherical_from_name(const char *name)
{
int i;
for (i = 0; i < FF_ARRAY_ELEMS(spherical_projection_names); i++) {
if (av_strstart(name, spherical_projection_names[i], NULL))
return i;
}
return -1;
}