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FFmpeg/libavcodec/imgconvert.c

253 lines
8.4 KiB
C

/*
* Misc image conversion routines
* Copyright (c) 2001, 2002, 2003 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* misc image conversion routines
*/
#include "avcodec.h"
#include "internal.h"
#include "mathops.h"
#include "libavutil/colorspace.h"
#include "libavutil/common.h"
#include "libavutil/pixdesc.h"
#include "libavutil/internal.h"
#include "libavutil/imgutils.h"
#if FF_API_GETCHROMA
void avcodec_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
*h_shift = desc->log2_chroma_w;
*v_shift = desc->log2_chroma_h;
}
#endif
static int is_gray(const AVPixFmtDescriptor *desc)
{
return desc->nb_components - (desc->flags & AV_PIX_FMT_FLAG_ALPHA) == 1;
}
int avcodec_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt,
enum AVPixelFormat src_pix_fmt,
int has_alpha)
{
const AVPixFmtDescriptor *src_desc = av_pix_fmt_desc_get(src_pix_fmt);
const AVPixFmtDescriptor *dst_desc = av_pix_fmt_desc_get(dst_pix_fmt);
int loss, i, nb_components = FFMIN(src_desc->nb_components,
dst_desc->nb_components);
/* compute loss */
loss = 0;
if (dst_pix_fmt == src_pix_fmt)
return 0;
for (i = 0; i < nb_components; i++)
if (src_desc->comp[i].depth > dst_desc->comp[i].depth)
loss |= FF_LOSS_DEPTH;
if (dst_desc->log2_chroma_w > src_desc->log2_chroma_w ||
dst_desc->log2_chroma_h > src_desc->log2_chroma_h)
loss |= FF_LOSS_RESOLUTION;
if ((src_desc->flags & AV_PIX_FMT_FLAG_RGB) != (dst_desc->flags & AV_PIX_FMT_FLAG_RGB))
loss |= FF_LOSS_COLORSPACE;
if (has_alpha && !(dst_desc->flags & AV_PIX_FMT_FLAG_ALPHA) &&
(src_desc->flags & AV_PIX_FMT_FLAG_ALPHA))
loss |= FF_LOSS_ALPHA;
if (dst_pix_fmt == AV_PIX_FMT_PAL8 && !is_gray(src_desc))
return loss | FF_LOSS_COLORQUANT;
if (src_desc->nb_components > dst_desc->nb_components)
if (is_gray(dst_desc))
loss |= FF_LOSS_CHROMA;
return loss;
}
static enum AVPixelFormat avcodec_find_best_pix_fmt1(enum AVPixelFormat *pix_fmt_list,
enum AVPixelFormat src_pix_fmt,
int has_alpha,
int loss_mask)
{
int dist, i, loss, min_dist;
enum AVPixelFormat dst_pix_fmt;
/* find exact color match with smallest size */
dst_pix_fmt = AV_PIX_FMT_NONE;
min_dist = 0x7fffffff;
i = 0;
while (pix_fmt_list[i] != AV_PIX_FMT_NONE) {
enum AVPixelFormat pix_fmt = pix_fmt_list[i];
if (i > AV_PIX_FMT_NB) {
av_log(NULL, AV_LOG_ERROR, "Pixel format list longer than expected, "
"it is either not properly terminated or contains duplicates\n");
return AV_PIX_FMT_NONE;
}
loss = avcodec_get_pix_fmt_loss(pix_fmt, src_pix_fmt, has_alpha) & loss_mask;
if (loss == 0) {
dist = av_get_bits_per_pixel(av_pix_fmt_desc_get(pix_fmt));
if (dist < min_dist) {
min_dist = dist;
dst_pix_fmt = pix_fmt;
}
}
i++;
}
return dst_pix_fmt;
}
enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat *pix_fmt_list,
enum AVPixelFormat src_pix_fmt,
int has_alpha, int *loss_ptr)
{
enum AVPixelFormat dst_pix_fmt;
int loss_mask, i;
static const int loss_mask_order[] = {
~0, /* no loss first */
~FF_LOSS_ALPHA,
~FF_LOSS_RESOLUTION,
~(FF_LOSS_COLORSPACE | FF_LOSS_RESOLUTION),
~FF_LOSS_COLORQUANT,
~FF_LOSS_DEPTH,
0,
};
/* try with successive loss */
i = 0;
for(;;) {
loss_mask = loss_mask_order[i++];
dst_pix_fmt = avcodec_find_best_pix_fmt1(pix_fmt_list, src_pix_fmt,
has_alpha, loss_mask);
if (dst_pix_fmt >= 0)
goto found;
if (loss_mask == 0)
break;
}
return AV_PIX_FMT_NONE;
found:
if (loss_ptr)
*loss_ptr = avcodec_get_pix_fmt_loss(dst_pix_fmt, src_pix_fmt, has_alpha);
return dst_pix_fmt;
}
#if FF_API_AVPICTURE
FF_DISABLE_DEPRECATION_WARNINGS
/* return true if yuv planar */
static inline int is_yuv_planar(const AVPixFmtDescriptor *desc)
{
return (!(desc->flags & AV_PIX_FMT_FLAG_RGB) &&
(desc->flags & AV_PIX_FMT_FLAG_PLANAR));
}
int av_picture_crop(AVPicture *dst, const AVPicture *src,
enum AVPixelFormat pix_fmt, int top_band, int left_band)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
int y_shift;
int x_shift;
if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB || !is_yuv_planar(desc))
return -1;
y_shift = desc->log2_chroma_h;
x_shift = desc->log2_chroma_w;
dst->data[0] = src->data[0] + (top_band * src->linesize[0]) + left_band;
dst->data[1] = src->data[1] + ((top_band >> y_shift) * src->linesize[1]) + (left_band >> x_shift);
dst->data[2] = src->data[2] + ((top_band >> y_shift) * src->linesize[2]) + (left_band >> x_shift);
dst->linesize[0] = src->linesize[0];
dst->linesize[1] = src->linesize[1];
dst->linesize[2] = src->linesize[2];
return 0;
}
int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width,
enum AVPixelFormat pix_fmt, int padtop, int padbottom, int padleft, int padright,
int *color)
{
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
uint8_t *optr;
int y_shift;
int x_shift;
int yheight;
int i, y;
if (pix_fmt < 0 || pix_fmt >= AV_PIX_FMT_NB ||
!is_yuv_planar(desc)) return -1;
for (i = 0; i < 3; i++) {
x_shift = i ? desc->log2_chroma_w : 0;
y_shift = i ? desc->log2_chroma_h : 0;
if (padtop || padleft) {
memset(dst->data[i], color[i],
dst->linesize[i] * (padtop >> y_shift) + (padleft >> x_shift));
}
if (padleft || padright) {
optr = dst->data[i] + dst->linesize[i] * (padtop >> y_shift) +
(dst->linesize[i] - (padright >> x_shift));
yheight = (height - 1 - (padtop + padbottom)) >> y_shift;
for (y = 0; y < yheight; y++) {
memset(optr, color[i], (padleft + padright) >> x_shift);
optr += dst->linesize[i];
}
}
if (src) { /* first line */
uint8_t *iptr = src->data[i];
optr = dst->data[i] + dst->linesize[i] * (padtop >> y_shift) +
(padleft >> x_shift);
memcpy(optr, iptr, (width - padleft - padright) >> x_shift);
iptr += src->linesize[i];
optr = dst->data[i] + dst->linesize[i] * (padtop >> y_shift) +
(dst->linesize[i] - (padright >> x_shift));
yheight = (height - 1 - (padtop + padbottom)) >> y_shift;
for (y = 0; y < yheight; y++) {
memset(optr, color[i], (padleft + padright) >> x_shift);
memcpy(optr + ((padleft + padright) >> x_shift), iptr,
(width - padleft - padright) >> x_shift);
iptr += src->linesize[i];
optr += dst->linesize[i];
}
}
if (padbottom || padright) {
optr = dst->data[i] + dst->linesize[i] *
((height - padbottom) >> y_shift) - (padright >> x_shift);
memset(optr, color[i],dst->linesize[i] *
(padbottom >> y_shift) + (padright >> x_shift));
}
}
return 0;
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif /* FF_API_AVPICTURE */