1/* 2 * Copyright (c) 2012 Stefano Sabatini 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a copy 5 * of this software and associated documentation files (the "Software"), to deal 6 * in the Software without restriction, including without limitation the rights 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 8 * copies of the Software, and to permit persons to whom the Software is 9 * furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice shall be included in 12 * all copies or substantial portions of the Software. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 17 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 20 * THE SOFTWARE. 21 */ 22 23/** 24 * @file 25 * libswscale API use example. 26 * @example scaling_video.c 27 */ 28 29#include <libavutil/imgutils.h> 30#include <libavutil/parseutils.h> 31#include <libswscale/swscale.h> 32 33static void fill_yuv_image(uint8_t *data[4], int linesize[4], 34 int width, int height, int frame_index) 35{ 36 int x, y; 37 38 /* Y */ 39 for (y = 0; y < height; y++) 40 for (x = 0; x < width; x++) 41 data[0][y * linesize[0] + x] = x + y + frame_index * 3; 42 43 /* Cb and Cr */ 44 for (y = 0; y < height / 2; y++) { 45 for (x = 0; x < width / 2; x++) { 46 data[1][y * linesize[1] + x] = 128 + y + frame_index * 2; 47 data[2][y * linesize[2] + x] = 64 + x + frame_index * 5; 48 } 49 } 50} 51 52int main(int argc, char **argv) 53{ 54 uint8_t *src_data[4], *dst_data[4]; 55 int src_linesize[4], dst_linesize[4]; 56 int src_w = 320, src_h = 240, dst_w, dst_h; 57 enum AVPixelFormat src_pix_fmt = AV_PIX_FMT_YUV420P, dst_pix_fmt = AV_PIX_FMT_RGB24; 58 const char *dst_size = NULL; 59 const char *dst_filename = NULL; 60 FILE *dst_file; 61 int dst_bufsize; 62 struct SwsContext *sws_ctx; 63 int i, ret; 64 65 if (argc != 3) { 66 fprintf(stderr, "Usage: %s output_file output_size\n" 67 "API example program to show how to scale an image with libswscale.\n" 68 "This program generates a series of pictures, rescales them to the given " 69 "output_size and saves them to an output file named output_file\n." 70 "\n", argv[0]); 71 exit(1); 72 } 73 dst_filename = argv[1]; 74 dst_size = argv[2]; 75 76 if (av_parse_video_size(&dst_w, &dst_h, dst_size) < 0) { 77 fprintf(stderr, 78 "Invalid size '%s', must be in the form WxH or a valid size abbreviation\n", 79 dst_size); 80 exit(1); 81 } 82 83 dst_file = fopen(dst_filename, "wb"); 84 if (!dst_file) { 85 fprintf(stderr, "Could not open destination file %s\n", dst_filename); 86 exit(1); 87 } 88 89 /* create scaling context */ 90 sws_ctx = sws_getContext(src_w, src_h, src_pix_fmt, 91 dst_w, dst_h, dst_pix_fmt, 92 SWS_BILINEAR, NULL, NULL, NULL); 93 if (!sws_ctx) { 94 fprintf(stderr, 95 "Impossible to create scale context for the conversion " 96 "fmt:%s s:%dx%d -> fmt:%s s:%dx%d\n", 97 av_get_pix_fmt_name(src_pix_fmt), src_w, src_h, 98 av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h); 99 ret = AVERROR(EINVAL); 100 goto end; 101 } 102 103 /* allocate source and destination image buffers */ 104 if ((ret = av_image_alloc(src_data, src_linesize, 105 src_w, src_h, src_pix_fmt, 16)) < 0) { 106 fprintf(stderr, "Could not allocate source image\n"); 107 goto end; 108 } 109 110 /* buffer is going to be written to rawvideo file, no alignment */ 111 if ((ret = av_image_alloc(dst_data, dst_linesize, 112 dst_w, dst_h, dst_pix_fmt, 1)) < 0) { 113 fprintf(stderr, "Could not allocate destination image\n"); 114 goto end; 115 } 116 dst_bufsize = ret; 117 118 for (i = 0; i < 100; i++) { 119 /* generate synthetic video */ 120 fill_yuv_image(src_data, src_linesize, src_w, src_h, i); 121 122 /* convert to destination format */ 123 sws_scale(sws_ctx, (const uint8_t * const*)src_data, 124 src_linesize, 0, src_h, dst_data, dst_linesize); 125 126 /* write scaled image to file */ 127 fwrite(dst_data[0], 1, dst_bufsize, dst_file); 128 } 129 130 fprintf(stderr, "Scaling succeeded. Play the output file with the command:\n" 131 "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n", 132 av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h, dst_filename); 133 134end: 135 if (dst_file) 136 fclose(dst_file); 137 av_freep(&src_data[0]); 138 av_freep(&dst_data[0]); 139 sws_freeContext(sws_ctx); 140 return ret < 0; 141} 142