| 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 | |
| 33 | static 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 | |
| 52 | int 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 | |
| 134 | end: |
| 135 | fclose(dst_file); |
| 136 | av_freep(&src_data[0]); |
| 137 | av_freep(&dst_data[0]); |
| 138 | sws_freeContext(sws_ctx); |
| 139 | return ret < 0; |
| 140 | } |