/*
  * 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
  */
 
 #include "libavutil/avstring.h"
 #include "libavutil/internal.h"
 #include "libavutil/opt.h"
 #include "avfilter.h"
 #include "audio.h"
 #include "formats.h"

 #include "framesync.h"

 #include "internal.h"
 #include "video.h"
 
 typedef struct StreamSelectContext {
     const AVClass *class;
     int nb_inputs;
     char *map_str;
     int *map;
     int nb_map;
     int is_audio;
     int64_t *last_pts;
     AVFrame **frames;
     FFFrameSync fs;
 } StreamSelectContext;
 
 #define OFFSET(x) offsetof(StreamSelectContext, x)
 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
 static const AVOption streamselect_options[] = {
     { "inputs",  "number of input streams",           OFFSET(nb_inputs),  AV_OPT_TYPE_INT,    {.i64=2},    2, INT_MAX,  .flags=FLAGS },
     { "map",     "input indexes to remap to outputs", OFFSET(map_str),    AV_OPT_TYPE_STRING, {.str=NULL},              .flags=FLAGS },
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(streamselect);
 
 static int process_frame(FFFrameSync *fs)
 {
     AVFilterContext *ctx = fs->parent;
     StreamSelectContext *s = fs->opaque;
     AVFrame **in = s->frames;
     int i, j, ret = 0;
 
     for (i = 0; i < ctx->nb_inputs; i++) {

         if ((ret = ff_framesync_get_frame(&s->fs, i, &in[i], 0)) < 0)

             return ret;
     }
 
     for (j = 0; j < ctx->nb_inputs; j++) {
         for (i = 0; i < s->nb_map; i++) {
             if (s->map[i] == j) {
                 AVFrame *out;
 
                 if (s->is_audio && s->last_pts[j] == in[j]->pts &&

                     ctx->outputs[i]->frame_count_in > 0)

                     continue;
                 out = av_frame_clone(in[j]);
                 if (!out)
                     return AVERROR(ENOMEM);
 
                 out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, ctx->outputs[i]->time_base);
                 s->last_pts[j] = in[j]->pts;
                 ret = ff_filter_frame(ctx->outputs[i], out);
                 if (ret < 0)
                     return ret;
             }
         }
     }
 
     return ret;
 }
 

 static int activate(AVFilterContext *ctx)

 {

     StreamSelectContext *s = ctx->priv;

     return ff_framesync_activate(&s->fs);

 }
 
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     StreamSelectContext *s = ctx->priv;
     const int outlink_idx = FF_OUTLINK_IDX(outlink);
     const int inlink_idx  = s->map[outlink_idx];
     AVFilterLink *inlink = ctx->inputs[inlink_idx];
     FFFrameSyncIn *in;
     int i, ret;
 
     av_log(ctx, AV_LOG_VERBOSE, "config output link %d "
            "with settings from input link %d\n",
            outlink_idx, inlink_idx);
 
     switch (outlink->type) {
     case AVMEDIA_TYPE_VIDEO:
         outlink->w = inlink->w;
         outlink->h = inlink->h;
         outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
         outlink->frame_rate = inlink->frame_rate;
         break;
     case AVMEDIA_TYPE_AUDIO:
         outlink->sample_rate    = inlink->sample_rate;
         outlink->channels       = inlink->channels;
         outlink->channel_layout = inlink->channel_layout;
         break;
     }
 
     outlink->time_base = inlink->time_base;
     outlink->format = inlink->format;
 
     if (s->fs.opaque == s)
         return 0;
 

     if ((ret = ff_framesync_init(&s->fs, ctx, ctx->nb_inputs)) < 0)

         return ret;
 
     in = s->fs.in;
     s->fs.opaque = s;
     s->fs.on_event = process_frame;
 
     for (i = 0; i < ctx->nb_inputs; i++) {
         in[i].time_base = ctx->inputs[i]->time_base;
         in[i].sync      = 1;
         in[i].before    = EXT_STOP;
         in[i].after     = EXT_STOP;
     }
 
     s->frames = av_calloc(ctx->nb_inputs, sizeof(*s->frames));
     if (!s->frames)
         return AVERROR(ENOMEM);
 

     return ff_framesync_configure(&s->fs);

 }
 

 static int parse_definition(AVFilterContext *ctx, int nb_pads, int is_input, int is_audio)

 {
     const char *padtype = is_input ? "in" : "out";
     int i = 0, ret = 0;
 
     for (i = 0; i < nb_pads; i++) {
         AVFilterPad pad = { 0 };
 
         pad.type = is_audio ? AVMEDIA_TYPE_AUDIO : AVMEDIA_TYPE_VIDEO;
 
         pad.name = av_asprintf("%sput%d", padtype, i);
         if (!pad.name)
             return AVERROR(ENOMEM);
 
         av_log(ctx, AV_LOG_DEBUG, "Add %s pad %s\n", padtype, pad.name);
 
         if (is_input) {
             ret = ff_insert_inpad(ctx, i, &pad);
         } else {
             pad.config_props  = config_output;
             ret = ff_insert_outpad(ctx, i, &pad);
         }
 
         if (ret < 0) {
             av_freep(&pad.name);
             return ret;
         }
     }
 
     return 0;
 }
 
 static int parse_mapping(AVFilterContext *ctx, const char *map)
 {
     StreamSelectContext *s = ctx->priv;
     int *new_map;
     int new_nb_map = 0;
 
     if (!map) {
         av_log(ctx, AV_LOG_ERROR, "mapping definition is not set\n");
         return AVERROR(EINVAL);
     }
 
     new_map = av_calloc(s->nb_inputs, sizeof(*new_map));
     if (!new_map)
         return AVERROR(ENOMEM);
 
     while (1) {
         char *p;
         const int n = strtol(map, &p, 0);
 
         av_log(ctx, AV_LOG_DEBUG, "n=%d map=%p p=%p\n", n, map, p);
 
         if (map == p)
             break;
         map = p;
 
         if (new_nb_map >= s->nb_inputs) {
             av_log(ctx, AV_LOG_ERROR, "Unable to map more than the %d "
                    "input pads available\n", s->nb_inputs);
             av_free(new_map);
             return AVERROR(EINVAL);
         }
 
         if (n < 0 || n >= ctx->nb_inputs) {
             av_log(ctx, AV_LOG_ERROR, "Input stream index %d doesn't exist "
                    "(there is only %d input streams defined)\n",
                    n, s->nb_inputs);
             av_free(new_map);
             return AVERROR(EINVAL);
         }
 
         av_log(ctx, AV_LOG_VERBOSE, "Map input stream %d to output stream %d\n", n, new_nb_map);
         new_map[new_nb_map++] = n;
     }
 
     if (!new_nb_map) {
         av_log(ctx, AV_LOG_ERROR, "invalid mapping\n");
         av_free(new_map);
         return AVERROR(EINVAL);
     }
 
     av_freep(&s->map);
     s->map = new_map;
     s->nb_map = new_nb_map;
 
     av_log(ctx, AV_LOG_VERBOSE, "%d map set\n", s->nb_map);
 
     return 0;
 }
 
 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
                            char *res, int res_len, int flags)
 {
     if (!strcmp(cmd, "map")) {
         int ret = parse_mapping(ctx, args);
 
         if (ret < 0)
             return ret;
         return avfilter_config_links(ctx);
     }
     return AVERROR(ENOSYS);
 }
 
 static av_cold int init(AVFilterContext *ctx)
 {
     StreamSelectContext *s = ctx->priv;
     int ret, nb_outputs = 0;
     char *map = s->map_str;
 
     if (!strcmp(ctx->filter->name, "astreamselect"))
         s->is_audio = 1;
 

     for (; map;) {

         char *p;
 
         strtol(map, &p, 0);
         if (map == p)
             break;
         nb_outputs++;
         map = p;
     }
 
     s->last_pts = av_calloc(s->nb_inputs, sizeof(*s->last_pts));
     if (!s->last_pts)
         return AVERROR(ENOMEM);
 

     if ((ret = parse_definition(ctx, s->nb_inputs, 1, s->is_audio)) < 0 ||
         (ret = parse_definition(ctx, nb_outputs, 0, s->is_audio)) < 0)

         return ret;
 
     av_log(ctx, AV_LOG_DEBUG, "Configured with %d inpad and %d outpad\n",
            ctx->nb_inputs, ctx->nb_outputs);
 
     return parse_mapping(ctx, s->map_str);
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     StreamSelectContext *s = ctx->priv;
 
     av_freep(&s->last_pts);
     av_freep(&s->map);
     av_freep(&s->frames);

     ff_framesync_uninit(&s->fs);

 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterFormats *formats, *rates = NULL;
     AVFilterChannelLayouts *layouts = NULL;
     int ret, i;
 
     for (i = 0; i < ctx->nb_inputs; i++) {
         formats = ff_all_formats(ctx->inputs[i]->type);
         if ((ret = ff_set_common_formats(ctx, formats)) < 0)
             return ret;
 
         if (ctx->inputs[i]->type == AVMEDIA_TYPE_AUDIO) {
             rates = ff_all_samplerates();
             if ((ret = ff_set_common_samplerates(ctx, rates)) < 0)
                 return ret;
             layouts = ff_all_channel_counts();
             if ((ret = ff_set_common_channel_layouts(ctx, layouts)) < 0)
                 return ret;
         }
     }
 
     return 0;
 }
 
 AVFilter ff_vf_streamselect = {
     .name            = "streamselect",
     .description     = NULL_IF_CONFIG_SMALL("Select video streams"),
     .init            = init,
     .query_formats   = query_formats,
     .process_command = process_command,
     .uninit          = uninit,

     .activate        = activate,

     .priv_size       = sizeof(StreamSelectContext),
     .priv_class      = &streamselect_class,
     .flags           = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_DYNAMIC_OUTPUTS,
 };
 
 #define astreamselect_options streamselect_options
 AVFILTER_DEFINE_CLASS(astreamselect);
 
 AVFilter ff_af_astreamselect = {
     .name            = "astreamselect",
     .description     = NULL_IF_CONFIG_SMALL("Select audio streams"),
     .init            = init,
     .query_formats   = query_formats,
     .process_command = process_command,
     .uninit          = uninit,

     .activate        = activate,

     .priv_size       = sizeof(StreamSelectContext),
     .priv_class      = &astreamselect_class,
     .flags           = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_DYNAMIC_OUTPUTS,
 };