/*
  * Copyright (c) 2010 Bobby Bingham
 
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**

  * @file

  * aspect ratio modification video filters

  */
 

 #include "libavutil/common.h"

 #include "libavutil/opt.h"

 #include "libavutil/mathematics.h"

 #include "libavutil/parseutils.h"

 #include "avfilter.h"

 #include "internal.h"

 #include "video.h"

 
 typedef struct {

     const AVClass *class;

     AVRational ratio;

     char *ratio_str;

     int max;

 } AspectContext;
 

 #define OFFSET(x) offsetof(AspectContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption options[] = {

     {"max", "set max value for nominator or denominator in the ratio", OFFSET(max), AV_OPT_TYPE_INT, {.i64=100}, 1, INT_MAX, FLAGS },

     {"ratio", "set ratio", OFFSET(ratio_str), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
     {"r",     "set ratio", OFFSET(ratio_str), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
     {NULL}
 };
 
 static av_cold int init(AVFilterContext *ctx, const char *args, const AVClass *class)

 {
     AspectContext *aspect = ctx->priv;

     static const char *shorthand[] = { "ratio", "max", NULL };

     char c;
     int ret;
     AVRational q;
 
     aspect->class = class;
     av_opt_set_defaults(aspect);
 
     if (sscanf(args, "%d:%d%c", &q.num, &q.den, &c) == 2) {
         aspect->ratio_str = av_strdup(args);
         av_log(ctx, AV_LOG_WARNING,
                "num:den syntax is deprecated, please use num/den or named options instead\n");
     } else if ((ret = av_opt_set_from_string(aspect, args, shorthand, "=", ":")) < 0) {
         return ret;
     }

     if (aspect->ratio_str) {

         ret = av_parse_ratio(&aspect->ratio, aspect->ratio_str, aspect->max, 0, ctx);

         if (ret < 0 || aspect->ratio.num < 0 || aspect->ratio.den <= 0) {

             av_log(ctx, AV_LOG_ERROR,

                    "Invalid string '%s' for aspect ratio\n", args);

             return AVERROR(EINVAL);

         }

     }

     av_log(ctx, AV_LOG_VERBOSE, "a:%d/%d\n", aspect->ratio.num, aspect->ratio.den);

     return 0;
 }
 

 static int filter_frame(AVFilterLink *link, AVFilterBufferRef *frame)

 {
     AspectContext *aspect = link->dst->priv;
 

     frame->video->sample_aspect_ratio = aspect->ratio;
     return ff_filter_frame(link->dst->outputs[0], frame);

 }
 

 static av_cold void uninit(AVFilterContext *ctx)
 {
     AspectContext *aspect = ctx->priv;
 
     av_opt_free(aspect);
 }
 

 #if CONFIG_SETDAR_FILTER

 
 #define setdar_options options
 AVFILTER_DEFINE_CLASS(setdar);
 
 static av_cold int setdar_init(AVFilterContext *ctx, const char *args)
 {
     return init(ctx, args, &setdar_class);
 }
 

 static int setdar_config_props(AVFilterLink *inlink)

 {
     AspectContext *aspect = inlink->dst->priv;

     AVRational dar = aspect->ratio;

     av_reduce(&aspect->ratio.num, &aspect->ratio.den,
                aspect->ratio.num * inlink->h,
                aspect->ratio.den * inlink->w, 100);

     av_log(inlink->dst, AV_LOG_VERBOSE, "w:%d h:%d -> dar:%d/%d sar:%d/%d\n",

            inlink->w, inlink->h, dar.num, dar.den, aspect->ratio.num, aspect->ratio.den);

     inlink->sample_aspect_ratio = aspect->ratio;

     return 0;
 }
 

 static const AVFilterPad avfilter_vf_setdar_inputs[] = {
     {
         .name             = "default",
         .type             = AVMEDIA_TYPE_VIDEO,
         .config_props     = setdar_config_props,
         .get_video_buffer = ff_null_get_video_buffer,

         .filter_frame     = filter_frame,

     },
     { NULL }
 };
 
 static const AVFilterPad avfilter_vf_setdar_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter avfilter_vf_setdar = {
     .name      = "setdar",
     .description = NULL_IF_CONFIG_SMALL("Set the frame display aspect ratio."),

     .init      = setdar_init,
     .uninit    = uninit,

 
     .priv_size = sizeof(AspectContext),
 

     .inputs    = avfilter_vf_setdar_inputs,
 
     .outputs   = avfilter_vf_setdar_outputs,

     .priv_class = &setdar_class,

 };

 #endif /* CONFIG_SETDAR_FILTER */

 #if CONFIG_SETSAR_FILTER

 
 #define setsar_options options
 AVFILTER_DEFINE_CLASS(setsar);
 
 static av_cold int setsar_init(AVFilterContext *ctx, const char *args)
 {
     return init(ctx, args, &setsar_class);
 }
 

 static int setsar_config_props(AVFilterLink *inlink)
 {
     AspectContext *aspect = inlink->dst->priv;
 

     inlink->sample_aspect_ratio = aspect->ratio;

 
     return 0;
 }
 

 static const AVFilterPad avfilter_vf_setsar_inputs[] = {
     {
         .name             = "default",
         .type             = AVMEDIA_TYPE_VIDEO,
         .config_props     = setsar_config_props,
         .get_video_buffer = ff_null_get_video_buffer,

         .filter_frame     = filter_frame,

     },
     { NULL }
 };
 
 static const AVFilterPad avfilter_vf_setsar_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter avfilter_vf_setsar = {
     .name      = "setsar",
     .description = NULL_IF_CONFIG_SMALL("Set the pixel sample aspect ratio."),

     .init      = setsar_init,
     .uninit    = uninit,

 
     .priv_size = sizeof(AspectContext),
 

     .inputs    = avfilter_vf_setsar_inputs,
 
     .outputs   = avfilter_vf_setsar_outputs,

     .priv_class = &setsar_class,

 };

 #endif /* CONFIG_SETSAR_FILTER */