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/*

 * 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 

#include 

#include 

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;

}