/* * Copyright (c) 2012 Stefano Sabatini * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ /** * @file * libswscale API use example. * @example scaling_video.c */ #include <libavutil/imgutils.h> #include <libavutil/parseutils.h> #include <libswscale/swscale.h> static void fill_yuv_image(uint8_t *data[4], int linesize[4], int width, int height, int frame_index) { int x, y; /* Y */ for (y = 0; y < height; y++) for (x = 0; x < width; x++) data[0][y * linesize[0] + x] = x + y + frame_index * 3; /* Cb and Cr */ for (y = 0; y < height / 2; y++) { for (x = 0; x < width / 2; x++) { data[1][y * linesize[1] + x] = 128 + y + frame_index * 2; data[2][y * linesize[2] + x] = 64 + x + frame_index * 5; } } } int main(int argc, char **argv) { uint8_t *src_data[4], *dst_data[4]; int src_linesize[4], dst_linesize[4]; int src_w = 320, src_h = 240, dst_w, dst_h; enum AVPixelFormat src_pix_fmt = AV_PIX_FMT_YUV420P, dst_pix_fmt = AV_PIX_FMT_RGB24; const char *dst_size = NULL; const char *dst_filename = NULL; FILE *dst_file; int dst_bufsize; struct SwsContext *sws_ctx; int i, ret; if (argc != 3) { fprintf(stderr, "Usage: %s output_file output_size\n" "API example program to show how to scale an image with libswscale.\n" "This program generates a series of pictures, rescales them to the given " "output_size and saves them to an output file named output_file\n." "\n", argv[0]); exit(1); } dst_filename = argv[1]; dst_size = argv[2]; if (av_parse_video_size(&dst_w, &dst_h, dst_size) < 0) { fprintf(stderr, "Invalid size '%s', must be in the form WxH or a valid size abbreviation\n", dst_size); exit(1); } dst_file = fopen(dst_filename, "wb"); if (!dst_file) { fprintf(stderr, "Could not open destination file %s\n", dst_filename); exit(1); } /* create scaling context */ sws_ctx = sws_getContext(src_w, src_h, src_pix_fmt, dst_w, dst_h, dst_pix_fmt, SWS_BILINEAR, NULL, NULL, NULL); if (!sws_ctx) { fprintf(stderr, "Impossible to create scale context for the conversion " "fmt:%s s:%dx%d -> fmt:%s s:%dx%d\n", av_get_pix_fmt_name(src_pix_fmt), src_w, src_h, av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h); ret = AVERROR(EINVAL); goto end; } /* allocate source and destination image buffers */ if ((ret = av_image_alloc(src_data, src_linesize, src_w, src_h, src_pix_fmt, 16)) < 0) { fprintf(stderr, "Could not allocate source image\n"); goto end; } /* buffer is going to be written to rawvideo file, no alignment */ if ((ret = av_image_alloc(dst_data, dst_linesize, dst_w, dst_h, dst_pix_fmt, 1)) < 0) { fprintf(stderr, "Could not allocate destination image\n"); goto end; } dst_bufsize = ret; for (i = 0; i < 100; i++) { /* generate synthetic video */ fill_yuv_image(src_data, src_linesize, src_w, src_h, i); /* convert to destination format */ sws_scale(sws_ctx, (const uint8_t * const*)src_data, src_linesize, 0, src_h, dst_data, dst_linesize); /* write scaled image to file */ fwrite(dst_data[0], 1, dst_bufsize, dst_file); } fprintf(stderr, "Scaling succeeded. Play the output file with the command:\n" "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n", av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h, dst_filename); end: fclose(dst_file); av_freep(&src_data[0]); av_freep(&dst_data[0]); sws_freeContext(sws_ctx); return ret < 0; }