/*

  * filter graphs

  * Copyright (c) 2008 Vitor Sessak
  * Copyright (c) 2007 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
  */
 

 #include <ctype.h>
 #include <string.h>
 

 #include "libavutil/audioconvert.h"

 #include "libavutil/avassert.h"

 #include "libavutil/pixdesc.h"

 #include "libavcodec/avcodec.h" // avcodec_find_best_pix_fmt_of_2()

 #include "avfilter.h"
 #include "avfiltergraph.h"

 #include "formats.h"

 #include "internal.h"

 #include "libavutil/audioconvert.h"

 #include "libavutil/avassert.h"

 #include "libavutil/common.h"

 #include "libavutil/log.h"
 
 static const AVClass filtergraph_class = {
     .class_name = "AVFilterGraph",

     .item_name  = av_default_item_name,

     .version    = LIBAVUTIL_VERSION_INT,

     .category   = AV_CLASS_CATEGORY_FILTER,

 };
 

 AVFilterGraph *avfilter_graph_alloc(void)
 {

     AVFilterGraph *ret = av_mallocz(sizeof(AVFilterGraph));
     if (!ret)
         return NULL;
     ret->av_class = &filtergraph_class;
     return ret;

 }
 

 void avfilter_graph_free(AVFilterGraph **graph)

 {

     if (!*graph)

         return;

     for (; (*graph)->filter_count > 0; (*graph)->filter_count--)
         avfilter_free((*graph)->filters[(*graph)->filter_count - 1]);

     av_freep(&(*graph)->sink_links);

     av_freep(&(*graph)->scale_sws_opts);
     av_freep(&(*graph)->filters);
     av_freep(graph);

 }
 

 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)

 {

     AVFilterContext **filters = av_realloc(graph->filters,
                                            sizeof(AVFilterContext*) * (graph->filter_count+1));
     if (!filters)

         return AVERROR(ENOMEM);

     graph->filters = filters;
     graph->filters[graph->filter_count++] = filter;

 
     return 0;

 }
 

 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
                                  const char *name, const char *args, void *opaque,
                                  AVFilterGraph *graph_ctx)
 {
     int ret;
 
     if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
         goto fail;
     if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
         goto fail;
     if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
         goto fail;
     return 0;
 
 fail:
     if (*filt_ctx)
         avfilter_free(*filt_ctx);
     *filt_ctx = NULL;
     return ret;
 }
 

 void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags)
 {
     graph->disable_auto_convert = flags;
 }
 

 /**
  * Check for the validity of graph.
  *
  * A graph is considered valid if all its input and output pads are
  * connected.
  *
  * @return 0 in case of success, a negative value otherwise
  */
 static int graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)

 {
     AVFilterContext *filt;
     int i, j;
 

     for (i = 0; i < graph->filter_count; i++) {

         filt = graph->filters[i];
 

         for (j = 0; j < filt->nb_inputs; j++) {

             if (!filt->inputs[j] || !filt->inputs[j]->src) {
                 av_log(log_ctx, AV_LOG_ERROR,
                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
                        filt->input_pads[j].name, filt->name, filt->filter->name);

                 return AVERROR(EINVAL);

             }
         }
 

         for (j = 0; j < filt->nb_outputs; j++) {

             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
                 av_log(log_ctx, AV_LOG_ERROR,
                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
                        filt->output_pads[j].name, filt->name, filt->filter->name);

                 return AVERROR(EINVAL);

             }
         }
     }
 
     return 0;
 }
 

 /**
  * Configure all the links of graphctx.
  *
  * @return 0 in case of success, a negative value otherwise
  */
 static int graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)

 {
     AVFilterContext *filt;
     int i, ret;
 
     for (i=0; i < graph->filter_count; i++) {
         filt = graph->filters[i];
 

         if (!filt->nb_outputs) {

             if ((ret = avfilter_config_links(filt)))
                 return ret;
         }
     }
 
     return 0;
 }
 

 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)

 {
     int i;
 

     for (i = 0; i < graph->filter_count; i++)
         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))

             return graph->filters[i];
 
     return NULL;
 }
 

 static int filter_query_formats(AVFilterContext *ctx)
 {
     int ret;
     AVFilterFormats *formats;
     AVFilterChannelLayouts *chlayouts;
     AVFilterFormats *samplerates;
     enum AVMediaType type = ctx->inputs  && ctx->inputs [0] ? ctx->inputs [0]->type :
                             ctx->outputs && ctx->outputs[0] ? ctx->outputs[0]->type :
                             AVMEDIA_TYPE_VIDEO;
 
     if ((ret = ctx->filter->query_formats(ctx)) < 0)
         return ret;
 

     formats = ff_all_formats(type);

     if (!formats)
         return AVERROR(ENOMEM);

     ff_set_common_formats(ctx, formats);

     if (type == AVMEDIA_TYPE_AUDIO) {
         samplerates = ff_all_samplerates();
         if (!samplerates)
             return AVERROR(ENOMEM);
         ff_set_common_samplerates(ctx, samplerates);
         chlayouts = ff_all_channel_layouts();
         if (!chlayouts)
             return AVERROR(ENOMEM);
         ff_set_common_channel_layouts(ctx, chlayouts);
     }
     return 0;
 }
 

 static int insert_conv_filter(AVFilterGraph *graph, AVFilterLink *link,
                               const char *filt_name, const char *filt_args)
 {
     static int auto_count = 0, ret;
     char inst_name[32];
     AVFilterContext *filt_ctx;
 

     if (graph->disable_auto_convert) {
         av_log(NULL, AV_LOG_ERROR,
                "The filters '%s' and '%s' do not have a common format "
                "and automatic conversion is disabled.\n",
                link->src->name, link->dst->name);
         return AVERROR(EINVAL);
     }
 

     snprintf(inst_name, sizeof(inst_name), "auto-inserted %s %d",
             filt_name, auto_count++);
 
     if ((ret = avfilter_graph_create_filter(&filt_ctx,
                                             avfilter_get_by_name(filt_name),
                                             inst_name, filt_args, NULL, graph)) < 0)
         return ret;
     if ((ret = avfilter_insert_filter(link, filt_ctx, 0, 0)) < 0)
         return ret;
 

     filter_query_formats(filt_ctx);

 
     if ( ((link = filt_ctx-> inputs[0]) &&

            !ff_merge_formats(link->in_formats, link->out_formats)) ||

          ((link = filt_ctx->outputs[0]) &&

            !ff_merge_formats(link->in_formats, link->out_formats))

        ) {
         av_log(NULL, AV_LOG_ERROR,
                "Impossible to convert between the formats supported by the filter "
                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
         return AVERROR(EINVAL);
     }
 
     if (link->type == AVMEDIA_TYPE_AUDIO &&
          (((link = filt_ctx-> inputs[0]) &&

            !ff_merge_channel_layouts(link->in_channel_layouts, link->out_channel_layouts)) ||

          ((link = filt_ctx->outputs[0]) &&

            !ff_merge_channel_layouts(link->in_channel_layouts, link->out_channel_layouts)))

        ) {
         av_log(NULL, AV_LOG_ERROR,

                "Impossible to convert between the channel layouts formats supported by the filter "

                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
         return AVERROR(EINVAL);
     }
 
     return 0;
 }
 

 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)

 {

     int i, j, ret;

     char filt_args[128];

     AVFilterFormats *formats;

     AVFilterChannelLayouts *chlayouts;
     AVFilterFormats *samplerates;

     int scaler_count = 0, resampler_count = 0;

     for (j = 0; j < 2; j++) {

     /* ask all the sub-filters for their supported media formats */

     for (i = 0; i < graph->filter_count; i++) {

         /* Call query_formats on sources first.
            This is a temporary workaround for amerge,
            until format renegociation is implemented. */

         if (!graph->filters[i]->nb_inputs == j)

             continue;

         if (graph->filters[i]->filter->query_formats)

             ret = filter_query_formats(graph->filters[i]);

         else

             ret = ff_default_query_formats(graph->filters[i]);
         if (ret < 0)
             return ret;

     }

     }

 
     /* go through and merge as many format lists as possible */

     for (i = 0; i < graph->filter_count; i++) {

         AVFilterContext *filter = graph->filters[i];
 

         for (j = 0; j < filter->nb_inputs; j++) {

             AVFilterLink *link = filter->inputs[j];

 #if 0

             if (!link) continue;
 
             if (!link->in_formats || !link->out_formats)
                 return AVERROR(EINVAL);
 
             if (link->type == AVMEDIA_TYPE_VIDEO &&

                 !ff_merge_formats(link->in_formats, link->out_formats)) {

 
                 /* couldn't merge format lists, auto-insert scale filter */
                 snprintf(filt_args, sizeof(filt_args), "0:0:%s",
                          graph->scale_sws_opts);
                 if (ret = insert_conv_filter(graph, link, "scale", filt_args))
                     return ret;
             }
             else if (link->type == AVMEDIA_TYPE_AUDIO) {

                 if (!link->in_channel_layouts || !link->out_channel_layouts)

                     return AVERROR(EINVAL);
 

                 /* Merge all three list before checking: that way, in all
                  * three categories, aconvert will use a common format
                  * whenever possible. */

                 formats     = ff_merge_formats(link->in_formats,   link->out_formats);

                 chlayouts   = ff_merge_channel_layouts(link->in_channel_layouts  , link->out_channel_layouts);
                 samplerates = ff_merge_samplerates    (link->in_samplerates, link->out_samplerates);
 

                 if (!formats || !chlayouts || !samplerates)

                     if (ret = insert_conv_filter(graph, link, "aresample", NULL))

                        return ret;

 #else

             int convert_needed = 0;
 
             if (!link)
                 continue;
 
             if (link->in_formats != link->out_formats &&

                 !ff_merge_formats(link->in_formats,

                                         link->out_formats))
                 convert_needed = 1;
             if (link->type == AVMEDIA_TYPE_AUDIO) {
                 if (link->in_channel_layouts != link->out_channel_layouts &&
                     !ff_merge_channel_layouts(link->in_channel_layouts,
                                               link->out_channel_layouts))
                     convert_needed = 1;
                 if (link->in_samplerates != link->out_samplerates &&
                     !ff_merge_samplerates(link->in_samplerates,
                                           link->out_samplerates))
                     convert_needed = 1;
             }
 
             if (convert_needed) {

                 AVFilterContext *convert;
                 AVFilter *filter;
                 AVFilterLink *inlink, *outlink;
                 char scale_args[256];
                 char inst_name[30];
 
                 /* couldn't merge format lists. auto-insert conversion filter */
                 switch (link->type) {
                 case AVMEDIA_TYPE_VIDEO:

                     if (!(filter = avfilter_get_by_name("scale"))) {
                         av_log(log_ctx, AV_LOG_ERROR, "'scale' filter "
                                "not present, cannot convert pixel formats.\n");
                         return AVERROR(EINVAL);
                     }
 

                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
                              scaler_count++);
                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);

                     if ((ret = avfilter_graph_create_filter(&convert, filter,

                                                             inst_name, scale_args, NULL,
                                                             graph)) < 0)
                         return ret;
                     break;
                 case AVMEDIA_TYPE_AUDIO:

                     if (!(filter = avfilter_get_by_name("aresample"))) {

                         av_log(log_ctx, AV_LOG_ERROR, "'aresample' filter "

                                "not present, cannot convert audio formats.\n");

                         return AVERROR(EINVAL);
                     }
 

                     snprintf(inst_name, sizeof(inst_name), "auto-inserted resampler %d",
                              resampler_count++);

                     if ((ret = avfilter_graph_create_filter(&convert, filter,

                                                             inst_name, NULL, NULL, graph)) < 0)

                         return ret;

                     break;
                 default:
                     return AVERROR(EINVAL);
                 }
 
                 if ((ret = avfilter_insert_filter(link, convert, 0, 0)) < 0)
                     return ret;
 

                 filter_query_formats(convert);

                 inlink  = convert->inputs[0];
                 outlink = convert->outputs[0];

                 if (!ff_merge_formats( inlink->in_formats,  inlink->out_formats) ||
                     !ff_merge_formats(outlink->in_formats, outlink->out_formats))

                     ret |= AVERROR(ENOSYS);
                 if (inlink->type == AVMEDIA_TYPE_AUDIO &&
                     (!ff_merge_samplerates(inlink->in_samplerates,
                                            inlink->out_samplerates) ||
                      !ff_merge_channel_layouts(inlink->in_channel_layouts,
                                                inlink->out_channel_layouts)))
                     ret |= AVERROR(ENOSYS);
                 if (outlink->type == AVMEDIA_TYPE_AUDIO &&
                     (!ff_merge_samplerates(outlink->in_samplerates,
                                            outlink->out_samplerates) ||
                      !ff_merge_channel_layouts(outlink->in_channel_layouts,
                                                outlink->out_channel_layouts)))
                     ret |= AVERROR(ENOSYS);
 
                 if (ret < 0) {
                     av_log(log_ctx, AV_LOG_ERROR,
                            "Impossible to convert between the formats supported by the filter "
                            "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
                     return ret;
                 }

 #endif

             }
         }
     }
 
     return 0;
 }
 

 static int pick_format(AVFilterLink *link, AVFilterLink *ref)

 {

     if (!link || !link->in_formats)

         return 0;

     if (link->type == AVMEDIA_TYPE_VIDEO) {
         if(ref && ref->type == AVMEDIA_TYPE_VIDEO){
             int has_alpha= av_pix_fmt_descriptors[ref->format].nb_components % 2 == 0;
             enum PixelFormat best= PIX_FMT_NONE;
             int i;
             for (i=0; i<link->in_formats->format_count; i++) {
                 enum PixelFormat p = link->in_formats->formats[i];

                 best= avcodec_find_best_pix_fmt_of_2(best, p, ref->format, has_alpha, NULL);

             }

             av_log(link->src,AV_LOG_DEBUG, "picking %s out of %d ref:%s alpha:%d\n",
                    av_get_pix_fmt_name(best), link->in_formats->format_count,
                    av_get_pix_fmt_name(ref->format), has_alpha);

             link->in_formats->formats[0] = best;
         }

     }
 

     link->in_formats->format_count = 1;

     link->format = link->in_formats->formats[0];

 
     if (link->type == AVMEDIA_TYPE_AUDIO) {

         if (!link->in_samplerates->format_count) {
             av_log(link->src, AV_LOG_ERROR, "Cannot select sample rate for"
                    " the link between filters %s and %s.\n", link->src->name,
                    link->dst->name);
             return AVERROR(EINVAL);
         }
         link->in_samplerates->format_count = 1;
         link->sample_rate = link->in_samplerates->formats[0];
 
         if (!link->in_channel_layouts->nb_channel_layouts) {
             av_log(link->src, AV_LOG_ERROR, "Cannot select channel layout for"
                    "the link between filters %s and %s.\n", link->src->name,
                    link->dst->name);
             return AVERROR(EINVAL);
         }
         link->in_channel_layouts->nb_channel_layouts = 1;
         link->channel_layout = link->in_channel_layouts->channel_layouts[0];

     }

     ff_formats_unref(&link->in_formats);
     ff_formats_unref(&link->out_formats);
     ff_formats_unref(&link->in_samplerates);
     ff_formats_unref(&link->out_samplerates);

     ff_channel_layouts_unref(&link->in_channel_layouts);
     ff_channel_layouts_unref(&link->out_channel_layouts);
 
     return 0;

 }
 

 #define REDUCE_FORMATS(fmt_type, list_type, list, var, nb, add_format) \
 do {                                                                   \

     for (i = 0; i < filter->nb_inputs; i++) {                          \

         AVFilterLink *link = filter->inputs[i];                        \
         fmt_type fmt;                                                  \
                                                                        \
         if (!link->out_ ## list || link->out_ ## list->nb != 1)        \
             continue;                                                  \
         fmt = link->out_ ## list->var[0];                              \
                                                                        \

         for (j = 0; j < filter->nb_outputs; j++) {                     \

             AVFilterLink *out_link = filter->outputs[j];               \
             list_type *fmts;                                           \
                                                                        \
             if (link->type != out_link->type ||                        \
                 out_link->in_ ## list->nb == 1)                        \
                 continue;                                              \
             fmts = out_link->in_ ## list;                              \
                                                                        \
             if (!out_link->in_ ## list->nb) {                          \
                 add_format(&out_link->in_ ##list, fmt);                \
                 break;                                                 \
             }                                                          \
                                                                        \
             for (k = 0; k < out_link->in_ ## list->nb; k++)            \
                 if (fmts->var[k] == fmt) {                             \
                     fmts->var[0]  = fmt;                               \
                     fmts->nb = 1;                                      \
                     ret = 1;                                           \
                     break;                                             \
                 }                                                      \
         }                                                              \
     }                                                                  \
 } while (0)
 

 static int reduce_formats_on_filter(AVFilterContext *filter)
 {
     int i, j, k, ret = 0;
 

     REDUCE_FORMATS(int,      AVFilterFormats,        formats,         formats,

                    format_count, ff_add_format);

     REDUCE_FORMATS(int,      AVFilterFormats,        samplerates,     formats,

                    format_count, ff_add_format);

     REDUCE_FORMATS(uint64_t, AVFilterChannelLayouts, channel_layouts,
                    channel_layouts, nb_channel_layouts, ff_add_channel_layout);

 
     return ret;
 }
 
 static void reduce_formats(AVFilterGraph *graph)
 {
     int i, reduced;
 
     do {
         reduced = 0;
 
         for (i = 0; i < graph->filter_count; i++)
             reduced |= reduce_formats_on_filter(graph->filters[i]);
     } while (reduced);
 }
 

 static void swap_samplerates_on_filter(AVFilterContext *filter)

 {

     AVFilterLink *link = NULL;
     int sample_rate;

     int i, j;

     for (i = 0; i < filter->nb_inputs; i++) {

         link = filter->inputs[i];
 
         if (link->type == AVMEDIA_TYPE_AUDIO &&
             link->out_samplerates->format_count == 1)
             break;
     }

     if (i == filter->nb_inputs)

         return;
 
     sample_rate = link->out_samplerates->formats[0];
 

     for (i = 0; i < filter->nb_outputs; i++) {

         AVFilterLink *outlink = filter->outputs[i];
         int best_idx, best_diff = INT_MAX;
 
         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
             outlink->in_samplerates->format_count < 2)
             continue;
 
         for (j = 0; j < outlink->in_samplerates->format_count; j++) {
             int diff = abs(sample_rate - outlink->in_samplerates->formats[j]);
 
             if (diff < best_diff) {
                 best_diff = diff;
                 best_idx  = j;
             }
         }
         FFSWAP(int, outlink->in_samplerates->formats[0],
                outlink->in_samplerates->formats[best_idx]);
     }
 }
 
 static void swap_samplerates(AVFilterGraph *graph)
 {
     int i;
 
     for (i = 0; i < graph->filter_count; i++)
         swap_samplerates_on_filter(graph->filters[i]);
 }
 

 #define CH_CENTER_PAIR (AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER)
 #define CH_FRONT_PAIR  (AV_CH_FRONT_LEFT           | AV_CH_FRONT_RIGHT)
 #define CH_STEREO_PAIR (AV_CH_STEREO_LEFT          | AV_CH_STEREO_RIGHT)
 #define CH_WIDE_PAIR   (AV_CH_WIDE_LEFT            | AV_CH_WIDE_RIGHT)
 #define CH_SIDE_PAIR   (AV_CH_SIDE_LEFT            | AV_CH_SIDE_RIGHT)
 #define CH_DIRECT_PAIR (AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT)
 #define CH_BACK_PAIR   (AV_CH_BACK_LEFT            | AV_CH_BACK_RIGHT)
 
 /* allowable substitutions for channel pairs when comparing layouts,
  * ordered by priority for both values */
 static const uint64_t ch_subst[][2] = {
     { CH_FRONT_PAIR,      CH_CENTER_PAIR     },
     { CH_FRONT_PAIR,      CH_WIDE_PAIR       },
     { CH_FRONT_PAIR,      AV_CH_FRONT_CENTER },
     { CH_CENTER_PAIR,     CH_FRONT_PAIR      },
     { CH_CENTER_PAIR,     CH_WIDE_PAIR       },
     { CH_CENTER_PAIR,     AV_CH_FRONT_CENTER },
     { CH_WIDE_PAIR,       CH_FRONT_PAIR      },
     { CH_WIDE_PAIR,       CH_CENTER_PAIR     },
     { CH_WIDE_PAIR,       AV_CH_FRONT_CENTER },
     { AV_CH_FRONT_CENTER, CH_FRONT_PAIR      },
     { AV_CH_FRONT_CENTER, CH_CENTER_PAIR     },
     { AV_CH_FRONT_CENTER, CH_WIDE_PAIR       },
     { CH_SIDE_PAIR,       CH_DIRECT_PAIR     },
     { CH_SIDE_PAIR,       CH_BACK_PAIR       },
     { CH_SIDE_PAIR,       AV_CH_BACK_CENTER  },
     { CH_BACK_PAIR,       CH_DIRECT_PAIR     },
     { CH_BACK_PAIR,       CH_SIDE_PAIR       },
     { CH_BACK_PAIR,       AV_CH_BACK_CENTER  },
     { AV_CH_BACK_CENTER,  CH_BACK_PAIR       },
     { AV_CH_BACK_CENTER,  CH_DIRECT_PAIR     },
     { AV_CH_BACK_CENTER,  CH_SIDE_PAIR       },
 };
 

 static void swap_channel_layouts_on_filter(AVFilterContext *filter)

 {

     AVFilterLink *link = NULL;

     int i, j, k;

     for (i = 0; i < filter->nb_inputs; i++) {

         link = filter->inputs[i];
 
         if (link->type == AVMEDIA_TYPE_AUDIO &&
             link->out_channel_layouts->nb_channel_layouts == 1)
             break;
     }

     if (i == filter->nb_inputs)

         return;
 

     for (i = 0; i < filter->nb_outputs; i++) {

         AVFilterLink *outlink = filter->outputs[i];

         int best_idx = -1, best_score = INT_MIN, best_count_diff = INT_MAX;

 
         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
             outlink->in_channel_layouts->nb_channel_layouts < 2)
             continue;
 
         for (j = 0; j < outlink->in_channel_layouts->nb_channel_layouts; j++) {

             uint64_t  in_chlayout = link->out_channel_layouts->channel_layouts[0];

             uint64_t out_chlayout = outlink->in_channel_layouts->channel_layouts[j];

             int  in_channels      = av_get_channel_layout_nb_channels(in_chlayout);
             int out_channels      = av_get_channel_layout_nb_channels(out_chlayout);
             int count_diff        = out_channels - in_channels;
             int matched_channels, extra_channels;
             int score = 0;
 
             /* channel substitution */
             for (k = 0; k < FF_ARRAY_ELEMS(ch_subst); k++) {
                 uint64_t cmp0 = ch_subst[k][0];
                 uint64_t cmp1 = ch_subst[k][1];
                 if (( in_chlayout & cmp0) && (!(out_chlayout & cmp0)) &&
                     (out_chlayout & cmp1) && (!( in_chlayout & cmp1))) {
                     in_chlayout  &= ~cmp0;
                     out_chlayout &= ~cmp1;
                     /* add score for channel match, minus a deduction for
                        having to do the substitution */
                     score += 10 * av_get_channel_layout_nb_channels(cmp1) - 2;
                 }
             }

             /* no penalty for LFE channel mismatch */
             if ( (in_chlayout & AV_CH_LOW_FREQUENCY) &&
                 (out_chlayout & AV_CH_LOW_FREQUENCY))
                 score += 10;
             in_chlayout  &= ~AV_CH_LOW_FREQUENCY;
             out_chlayout &= ~AV_CH_LOW_FREQUENCY;
 
             matched_channels = av_get_channel_layout_nb_channels(in_chlayout &
                                                                  out_chlayout);
             extra_channels   = av_get_channel_layout_nb_channels(out_chlayout &
                                                                  (~in_chlayout));
             score += 10 * matched_channels - 5 * extra_channels;
 
             if (score > best_score ||
                 (count_diff < best_count_diff && score == best_score)) {

                 best_score = score;
                 best_idx   = j;

                 best_count_diff = count_diff;

             }
         }

         av_assert0(best_idx >= 0);

         FFSWAP(uint64_t, outlink->in_channel_layouts->channel_layouts[0],
                outlink->in_channel_layouts->channel_layouts[best_idx]);
     }
 
 }
 
 static void swap_channel_layouts(AVFilterGraph *graph)
 {
     int i;
 
     for (i = 0; i < graph->filter_count; i++)
         swap_channel_layouts_on_filter(graph->filters[i]);
 }
 

 static void swap_sample_fmts_on_filter(AVFilterContext *filter)
 {
     AVFilterLink *link = NULL;
     int format, bps;
     int i, j;
 

     for (i = 0; i < filter->nb_inputs; i++) {

         link = filter->inputs[i];
 
         if (link->type == AVMEDIA_TYPE_AUDIO &&
             link->out_formats->format_count == 1)
             break;
     }

     if (i == filter->nb_inputs)

         return;
 
     format = link->out_formats->formats[0];
     bps    = av_get_bytes_per_sample(format);
 

     for (i = 0; i < filter->nb_outputs; i++) {

         AVFilterLink *outlink = filter->outputs[i];

         int best_idx = -1, best_score = INT_MIN;

 
         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
             outlink->in_formats->format_count < 2)
             continue;
 
         for (j = 0; j < outlink->in_formats->format_count; j++) {
             int out_format = outlink->in_formats->formats[j];
             int out_bps    = av_get_bytes_per_sample(out_format);
             int score;
 
             if (av_get_packed_sample_fmt(out_format) == format ||
                 av_get_planar_sample_fmt(out_format) == format) {
                 best_idx   = j;
                 break;
             }
 
             /* for s32 and float prefer double to prevent loss of information */
             if (bps == 4 && out_bps == 8) {
                 best_idx = j;
                 break;
             }
 
             /* prefer closest higher or equal bps */
             score = -abs(out_bps - bps);
             if (out_bps >= bps)
                 score += INT_MAX/2;
 
             if (score > best_score) {
                 best_score = score;
                 best_idx   = j;
             }
         }

         av_assert0(best_idx >= 0);

         FFSWAP(int, outlink->in_formats->formats[0],
                outlink->in_formats->formats[best_idx]);
     }
 }
 
 static void swap_sample_fmts(AVFilterGraph *graph)
 {
     int i;
 
     for (i = 0; i < graph->filter_count; i++)
         swap_sample_fmts_on_filter(graph->filters[i]);
 
 }
 

 static int pick_formats(AVFilterGraph *graph)
 {
     int i, j, ret;

     int change;
 
     do{
         change = 0;
         for (i = 0; i < graph->filter_count; i++) {
             AVFilterContext *filter = graph->filters[i];

             if (filter->nb_inputs){
                 for (j = 0; j < filter->nb_inputs; j++){

                     if(filter->inputs[j]->in_formats && filter->inputs[j]->in_formats->format_count == 1) {
                         pick_format(filter->inputs[j], NULL);
                         change = 1;
                     }
                 }
             }

             if (filter->nb_outputs){
                 for (j = 0; j < filter->nb_outputs; j++){

                     if(filter->outputs[j]->in_formats && filter->outputs[j]->in_formats->format_count == 1) {
                         pick_format(filter->outputs[j], NULL);
                         change = 1;
                     }
                 }
             }

             if (filter->nb_inputs && filter->nb_outputs && filter->inputs[0]->format>=0) {
                 for (j = 0; j < filter->nb_outputs; j++) {

                     if(filter->outputs[j]->format<0) {
                         pick_format(filter->outputs[j], filter->inputs[0]);
                         change = 1;
                     }
                 }
             }

         }

     }while(change);
 

     for (i = 0; i < graph->filter_count; i++) {
         AVFilterContext *filter = graph->filters[i];

         for (j = 0; j < filter->nb_inputs; j++)

             if ((ret = pick_format(filter->inputs[j], NULL)) < 0)

                 return ret;

         for (j = 0; j < filter->nb_outputs; j++)

             if ((ret = pick_format(filter->outputs[j], NULL)) < 0)

                 return ret;

     }

     return 0;

 }
 

 /**
  * Configure the formats of all the links in the graph.
  */
 static int graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)

 {

     int ret;
 

     /* find supported formats from sub-filters, and merge along links */

     if ((ret = query_formats(graph, log_ctx)) < 0)
         return ret;

 
     /* Once everything is merged, it's possible that we'll still have

      * multiple valid media format choices. We try to minimize the amount
      * of format conversion inside filters */
     reduce_formats(graph);
 

     /* for audio filters, ensure the best format, sample rate and channel layout

      * is selected */

     swap_sample_fmts(graph);

     swap_samplerates(graph);
     swap_channel_layouts(graph);
 
     if ((ret = pick_formats(graph)) < 0)
         return ret;

 
     return 0;
 }
 

 static int ff_avfilter_graph_config_pointers(AVFilterGraph *graph,
                                              AVClass *log_ctx)

 {

     unsigned i, j;
     int sink_links_count = 0, n = 0;

     AVFilterContext *f;

     AVFilterLink **sinks;

 
     for (i = 0; i < graph->filter_count; i++) {
         f = graph->filters[i];

         for (j = 0; j < f->nb_inputs; j++) {

             f->inputs[j]->graph     = graph;
             f->inputs[j]->age_index = -1;
         }

         for (j = 0; j < f->nb_outputs; j++) {

             f->outputs[j]->graph    = graph;
             f->outputs[j]->age_index= -1;
         }

         if (!f->nb_outputs) {
             if (f->nb_inputs > INT_MAX - sink_links_count)

                 return AVERROR(EINVAL);

             sink_links_count += f->nb_inputs;

         }

     }

     sinks = av_calloc(sink_links_count, sizeof(*sinks));
     if (!sinks)
         return AVERROR(ENOMEM);
     for (i = 0; i < graph->filter_count; i++) {
         f = graph->filters[i];

         if (!f->nb_outputs) {
             for (j = 0; j < f->nb_inputs; j++) {

                 sinks[n] = f->inputs[j];
                 f->inputs[j]->age_index = n++;
             }
         }
     }
     av_assert0(n == sink_links_count);
     graph->sink_links       = sinks;
     graph->sink_links_count = sink_links_count;
     return 0;

 }
 

 static int graph_insert_fifos(AVFilterGraph *graph, AVClass *log_ctx)
 {
     AVFilterContext *f;
     int i, j, ret;
     int fifo_count = 0;
 
     for (i = 0; i < graph->filter_count; i++) {
         f = graph->filters[i];
 
         for (j = 0; j < f->nb_inputs; j++) {
             AVFilterLink *link = f->inputs[j];
             AVFilterContext *fifo_ctx;
             AVFilter *fifo;
             char name[32];
 
             if (!link->dstpad->needs_fifo)
                 continue;
 
             fifo = f->inputs[j]->type == AVMEDIA_TYPE_VIDEO ?
                    avfilter_get_by_name("fifo") :
                    avfilter_get_by_name("afifo");
 
             snprintf(name, sizeof(name), "auto-inserted fifo %d", fifo_count++);
 
             ret = avfilter_graph_create_filter(&fifo_ctx, fifo, name, NULL,
                                                NULL, graph);
             if (ret < 0)
                 return ret;
 
             ret = avfilter_insert_filter(link, fifo_ctx, 0, 0);
             if (ret < 0)
                 return ret;
         }
     }
 
     return 0;
 }
 

 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)

 {
     int ret;
 

     if ((ret = graph_check_validity(graphctx, log_ctx)))

         return ret;

     if ((ret = graph_insert_fifos(graphctx, log_ctx)) < 0)
         return ret;

     if ((ret = graph_config_formats(graphctx, log_ctx)))

         return ret;

     if ((ret = graph_config_links(graphctx, log_ctx)))

         return ret;

     if ((ret = ff_avfilter_graph_config_pointers(graphctx, log_ctx)))
         return ret;

 
     return 0;
 }

 
 int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags)
 {
     int i, r = AVERROR(ENOSYS);
 
     if(!graph)
         return r;
 
     if((flags & AVFILTER_CMD_FLAG_ONE) && !(flags & AVFILTER_CMD_FLAG_FAST)) {
         r=avfilter_graph_send_command(graph, target, cmd, arg, res, res_len, flags | AVFILTER_CMD_FLAG_FAST);
         if(r != AVERROR(ENOSYS))
             return r;
     }
 
     if(res_len && res)
         res[0]= 0;
 
     for (i = 0; i < graph->filter_count; i++) {
         AVFilterContext *filter = graph->filters[i];

         if(!strcmp(target, "all") || (filter->name && !strcmp(target, filter->name)) || !strcmp(target, filter->filter->name)){

             r = avfilter_process_command(filter, cmd, arg, res, res_len, flags);
             if(r != AVERROR(ENOSYS)) {
                 if((flags & AVFILTER_CMD_FLAG_ONE) || r<0)
                     return r;
             }
         }
     }
 
     return r;
 }

 
 int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *command, const char *arg, int flags, double ts)
 {
     int i;
 
     if(!graph)
         return 0;
 
     for (i = 0; i < graph->filter_count; i++) {
         AVFilterContext *filter = graph->filters[i];
         if(filter && (!strcmp(target, "all") || !strcmp(target, filter->name) || !strcmp(target, filter->filter->name))){

             AVFilterCommand **que = &filter->command_queue, *next;
             while(*que && (*que)->time <= ts)
                 que = &(*que)->next;
             next= *que;

             *que= av_mallocz(sizeof(AVFilterCommand));
             (*que)->command = av_strdup(command);
             (*que)->arg     = av_strdup(arg);
             (*que)->time    = ts;
             (*que)->flags   = flags;

             (*que)->next    = next;

             if(flags & AVFILTER_CMD_FLAG_ONE)
                 return 0;
         }
     }
 
     return 0;
 }

 
 static void heap_bubble_up(AVFilterGraph *graph,
                            AVFilterLink *link, int index)
 {
     AVFilterLink **links = graph->sink_links;
 
     while (index) {
         int parent = (index - 1) >> 1;
         if (links[parent]->current_pts >= link->current_pts)
             break;
         links[index] = links[parent];
         links[index]->age_index = index;
         index = parent;
     }
     links[index] = link;
     link->age_index = index;
 }
 
 static void heap_bubble_down(AVFilterGraph *graph,
                              AVFilterLink *link, int index)
 {
     AVFilterLink **links = graph->sink_links;
 
     while (1) {
         int child = 2 * index + 1;
         if (child >= graph->sink_links_count)
             break;
         if (child + 1 < graph->sink_links_count &&
             links[child + 1]->current_pts < links[child]->current_pts)
             child++;
         if (link->current_pts < links[child]->current_pts)
             break;
         links[index] = links[child];
         links[index]->age_index = index;
         index = child;
     }
     links[index] = link;
     link->age_index = index;
 }
 
 void ff_avfilter_graph_update_heap(AVFilterGraph *graph, AVFilterLink *link)
 {
     heap_bubble_up  (graph, link, link->age_index);
     heap_bubble_down(graph, link, link->age_index);
 }
 
 
 int avfilter_graph_request_oldest(AVFilterGraph *graph)
 {
     while (graph->sink_links_count) {
         AVFilterLink *oldest = graph->sink_links[0];

         int r = ff_request_frame(oldest);

         if (r != AVERROR_EOF)
             return r;

         av_log(oldest->dst, AV_LOG_DEBUG, "EOF on sink link %s:%s.\n",
                oldest->dst ? oldest->dst->name : "unknown",
                oldest->dstpad ? oldest->dstpad->name : "unknown");

         /* EOF: remove the link from the heap */
         if (oldest->age_index < --graph->sink_links_count)
             heap_bubble_down(graph, graph->sink_links[graph->sink_links_count],
                              oldest->age_index);
         oldest->age_index = -1;
     }
     return AVERROR_EOF;
 }