FFmpeg
lswsutils.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include "libavutil/imgutils.h"
20 #include "lswsutils.h"
21 
22 int ff_scale_image(uint8_t *dst_data[4], int dst_linesize[4],
23  int dst_w, int dst_h, enum AVPixelFormat dst_pix_fmt,
24  uint8_t * const src_data[4], int src_linesize[4],
25  int src_w, int src_h, enum AVPixelFormat src_pix_fmt,
26  void *log_ctx)
27 {
28  int ret;
29  struct SwsContext *sws_ctx = sws_getContext(src_w, src_h, src_pix_fmt,
30  dst_w, dst_h, dst_pix_fmt,
31  0, NULL, NULL, NULL);
32  if (!sws_ctx) {
33  av_log(log_ctx, AV_LOG_ERROR,
34  "Impossible to create scale context for the conversion "
35  "fmt:%s s:%dx%d -> fmt:%s s:%dx%d\n",
36  av_get_pix_fmt_name(src_pix_fmt), src_w, src_h,
37  av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h);
38  ret = AVERROR(EINVAL);
39  goto end;
40  }
41 
42  if ((ret = av_image_alloc(dst_data, dst_linesize, dst_w, dst_h, dst_pix_fmt, 16)) < 0)
43  goto end;
44  ret = 0;
45  sws_scale(sws_ctx, (const uint8_t * const*)src_data, src_linesize, 0, src_h, dst_data, dst_linesize);
46 
47 end:
48  sws_freeContext(sws_ctx);
49  return ret;
50 }
#define NULL
Definition: coverity.c:32
misc image utilities
int av_image_alloc(uint8_t *pointers[4], int linesizes[4], int w, int h, enum AVPixelFormat pix_fmt, int align)
Allocate an image with size w and h and pixel format pix_fmt, and fill pointers and linesizes accordi...
Definition: imgutils.c:192
Miscellaneous utilities which make use of the libswscale library.
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int ff_scale_image(uint8_t *dst_data[4], int dst_linesize[4], int dst_w, int dst_h, enum AVPixelFormat dst_pix_fmt, uint8_t *const src_data[4], int src_linesize[4], int src_w, int src_h, enum AVPixelFormat src_pix_fmt, void *log_ctx)
Scale image using libswscale.
Definition: lswsutils.c:22
struct SwsContext * sws_getContext(int srcW, int srcH, enum AVPixelFormat srcFormat, int dstW, int dstH, enum AVPixelFormat dstFormat, int flags, SwsFilter *srcFilter, SwsFilter *dstFilter, const double *param)
Allocate and return an SwsContext.
Definition: utils.c:1891
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
void sws_freeContext(struct SwsContext *swsContext)
Free the swscaler context swsContext.
Definition: utils.c:2311
int attribute_align_arg sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[], const int srcStride[], int srcSliceY, int srcSliceH, uint8_t *const dst[], const int dstStride[])
swscale wrapper, so we don&#39;t need to export the SwsContext.
Definition: swscale.c:753
const char * av_get_pix_fmt_name(enum AVPixelFormat pix_fmt)
Return the short name for a pixel format, NULL in case pix_fmt is unknown.
Definition: pixdesc.c:2438
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64