/*

  * 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 "config.h"
 

 #include <string.h>
 

 #include "libavutil/avassert.h"

 #include "libavutil/avstring.h"

 #include "libavutil/bprint.h"

 #include "libavutil/channel_layout.h"

 #include "libavutil/internal.h"

 #include "libavutil/opt.h"

 #include "libavutil/pixdesc.h"

 #include "avfilter.h"

 #include "formats.h"

 #include "internal.h"

 #include "thread.h"
 
 #define OFFSET(x) offsetof(AVFilterGraph, x)

 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

 static const AVOption filtergraph_options[] = {
     { "thread_type", "Allowed thread types", OFFSET(thread_type), AV_OPT_TYPE_FLAGS,
         { .i64 = AVFILTER_THREAD_SLICE }, 0, INT_MAX, FLAGS, "thread_type" },
         { "slice", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = AVFILTER_THREAD_SLICE }, .flags = FLAGS, .unit = "thread_type" },
     { "threads",     "Maximum number of threads", OFFSET(nb_threads),
         AV_OPT_TYPE_INT,   { .i64 = 0 }, 0, INT_MAX, FLAGS },

     {"scale_sws_opts"       , "default scale filter options"        , OFFSET(scale_sws_opts)        ,
         AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
     {"aresample_swr_opts"   , "default aresample filter options"    , OFFSET(aresample_swr_opts)    ,
         AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },

     { NULL },

 };
 

 static const AVClass filtergraph_class = {
     .class_name = "AVFilterGraph",

     .item_name  = av_default_item_name,

     .version    = LIBAVUTIL_VERSION_INT,

     .option     = filtergraph_options,

     .category   = AV_CLASS_CATEGORY_FILTER,

 };
 

 #if !HAVE_THREADS
 void ff_graph_thread_free(AVFilterGraph *graph)
 {
 }
 
 int ff_graph_thread_init(AVFilterGraph *graph)
 {
     graph->thread_type = 0;
     graph->nb_threads  = 1;
     return 0;
 }
 #endif
 

 AVFilterGraph *avfilter_graph_alloc(void)
 {

     AVFilterGraph *ret = av_mallocz(sizeof(*ret));

     if (!ret)
         return NULL;

 
     ret->internal = av_mallocz(sizeof(*ret->internal));
     if (!ret->internal) {
         av_freep(&ret);
         return NULL;
     }
 

     ret->av_class = &filtergraph_class;

     av_opt_set_defaults(ret);
 

     return ret;

 }
 

 void ff_filter_graph_remove_filter(AVFilterGraph *graph, AVFilterContext *filter)
 {
     int i;
     for (i = 0; i < graph->nb_filters; i++) {
         if (graph->filters[i] == filter) {
             FFSWAP(AVFilterContext*, graph->filters[i],
                    graph->filters[graph->nb_filters - 1]);
             graph->nb_filters--;
             return;
         }
     }
 }
 

 void avfilter_graph_free(AVFilterGraph **graph)

 {

     if (!*graph)

         return;

 
     while ((*graph)->nb_filters)
         avfilter_free((*graph)->filters[0]);
 

     ff_graph_thread_free(*graph);
 

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

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

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

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

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

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

     av_freep(graph);

 }
 

 #if FF_API_AVFILTER_OPEN

 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)

 {

     AVFilterContext **filters = av_realloc(graph->filters,

                                            sizeof(*filters) * (graph->nb_filters + 1));

     if (!filters)

         return AVERROR(ENOMEM);

     graph->filters = filters;

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

 #if FF_API_FOO_COUNT

 FF_DISABLE_DEPRECATION_WARNINGS

     graph->filter_count_unused = graph->nb_filters;

 FF_ENABLE_DEPRECATION_WARNINGS

 #endif
 

     filter->graph = graph;
 

     return 0;

 }

 #endif

 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,

                                  const char *name, const char *args, void *opaque,
                                  AVFilterGraph *graph_ctx)
 {
     int ret;
 

     *filt_ctx = avfilter_graph_alloc_filter(graph_ctx, filt, name);
     if (!*filt_ctx)
         return AVERROR(ENOMEM);

     ret = avfilter_init_str(*filt_ctx, args);

     if (ret < 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;
 }
 

 AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
                                              const AVFilter *filter,
                                              const char *name)
 {
     AVFilterContext **filters, *s;
 

     if (graph->thread_type && !graph->internal->thread_execute) {
         if (graph->execute) {
             graph->internal->thread_execute = graph->execute;
         } else {
             int ret = ff_graph_thread_init(graph);
             if (ret < 0) {
                 av_log(graph, AV_LOG_ERROR, "Error initializing threading.\n");
                 return NULL;
             }

         }
     }
 

     s = ff_filter_alloc(filter, name);
     if (!s)
         return NULL;
 
     filters = av_realloc(graph->filters, sizeof(*filters) * (graph->nb_filters + 1));
     if (!filters) {
         avfilter_free(s);
         return NULL;
     }
 
     graph->filters = filters;
     graph->filters[graph->nb_filters++] = s;
 
 #if FF_API_FOO_COUNT

 FF_DISABLE_DEPRECATION_WARNINGS

     graph->filter_count_unused = graph->nb_filters;

 FF_ENABLE_DEPRECATION_WARNINGS

 #endif
 

     s->graph = graph;
 

     return s;
 }
 

 /**
  * 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->nb_filters; i++) {

         const AVFilterPad *pad;

         filt = graph->filters[i];
 

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

             if (!filt->inputs[j] || !filt->inputs[j]->src) {

                 pad = &filt->input_pads[j];

                 av_log(log_ctx, AV_LOG_ERROR,

                        "Input pad \"%s\" with type %s of the filter instance \"%s\" of %s not connected to any source\n",
                        pad->name, av_get_media_type_string(pad->type), filt->name, filt->filter->name);

                 return AVERROR(EINVAL);

             }
         }
 

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

             if (!filt->outputs[j] || !filt->outputs[j]->dst) {

                 pad = &filt->output_pads[j];

                 av_log(log_ctx, AV_LOG_ERROR,

                        "Output pad \"%s\" with type %s of the filter instance \"%s\" of %s not connected to any destination\n",
                        pad->name, av_get_media_type_string(pad->type), 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->nb_filters; 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, const char *name)

 {
     int i;
 

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

         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))

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

 static void sanitize_channel_layouts(void *log, AVFilterChannelLayouts *l)
 {
     if (!l)
         return;
     if (l->nb_channel_layouts) {
         if (l->all_layouts || l->all_counts)
             av_log(log, AV_LOG_WARNING, "All layouts set on non-empty list\n");
         l->all_layouts = l->all_counts = 0;
     } else {
         if (l->all_counts && !l->all_layouts)
             av_log(log, AV_LOG_WARNING, "All counts without all layouts\n");
         l->all_layouts = 1;
     }
 }
 

 static int filter_query_formats(AVFilterContext *ctx)
 {

     int ret, i;

     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) {

         if (ret != AVERROR(EAGAIN))
             av_log(ctx, AV_LOG_ERROR, "Query format failed for '%s': %s\n",
                    ctx->name, av_err2str(ret));

         return ret;

     }

     for (i = 0; i < ctx->nb_inputs; i++)
         sanitize_channel_layouts(ctx, ctx->inputs[i]->out_channel_layouts);
     for (i = 0; i < ctx->nb_outputs; i++)
         sanitize_channel_layouts(ctx, ctx->outputs[i]->in_channel_layouts);
 

     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 formats_declared(AVFilterContext *f)
 {
     int i;
 
     for (i = 0; i < f->nb_inputs; i++) {
         if (!f->inputs[i]->out_formats)
             return 0;
         if (f->inputs[i]->type == AVMEDIA_TYPE_AUDIO &&
             !(f->inputs[i]->out_samplerates &&
               f->inputs[i]->out_channel_layouts))
             return 0;
     }
     for (i = 0; i < f->nb_outputs; i++) {
         if (!f->outputs[i]->in_formats)
             return 0;
         if (f->outputs[i]->type == AVMEDIA_TYPE_AUDIO &&
             !(f->outputs[i]->in_samplerates &&
               f->outputs[i]->in_channel_layouts))
             return 0;
     }
     return 1;
 }
 

 static AVFilterFormats *clone_filter_formats(AVFilterFormats *arg)
 {
     AVFilterFormats *a = av_memdup(arg, sizeof(*arg));
     if (a) {
         a->refcount = 0;
         a->refs     = NULL;
         a->formats  = av_memdup(a->formats, sizeof(*a->formats) * a->nb_formats);
         if (!a->formats && arg->formats)
             av_freep(&a);
     }
     return a;
 }
 
 static int can_merge_formats(AVFilterFormats *a_arg,
                              AVFilterFormats *b_arg,
                              enum AVMediaType type,
                              int is_sample_rate)
 {
     AVFilterFormats *a, *b, *ret;

     if (a_arg == b_arg)

         return 1;
     a = clone_filter_formats(a_arg);
     b = clone_filter_formats(b_arg);

 
     if (!a || !b) {
         if (a)
             av_freep(&a->formats);
         if (b)
             av_freep(&b->formats);
 
         av_freep(&a);
         av_freep(&b);
 
         return 0;
     }
 

     if (is_sample_rate) {
         ret = ff_merge_samplerates(a, b);
     } else {
         ret = ff_merge_formats(a, b, type);
     }
     if (ret) {
         av_freep(&ret->formats);

         av_freep(&ret->refs);

         av_freep(&ret);
         return 1;
     } else {
         av_freep(&a->formats);
         av_freep(&b->formats);
         av_freep(&a);
         av_freep(&b);
         return 0;
     }
 }
 

 /**
  * Perform one round of query_formats() and merging formats lists on the
  * filter graph.
  * @return  >=0 if all links formats lists could be queried and merged;
  *          AVERROR(EAGAIN) some progress was made in the queries or merging
  *          and a later call may succeed;
  *          AVERROR(EIO) (may be changed) plus a log message if no progress
  *          was made and the negotiation is stuck;
  *          a negative error code if some other error happened
  */

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

 {

     int i, j, ret;

     int scaler_count = 0, resampler_count = 0;

     int count_queried = 0;        /* successful calls to query_formats() */
     int count_merged = 0;         /* successful merge of formats lists */
     int count_already_merged = 0; /* lists already merged */
     int count_delayed = 0;        /* lists that need to be merged later */

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

         AVFilterContext *f = graph->filters[i];
         if (formats_declared(f))

             continue;

         if (f->filter->query_formats)
             ret = filter_query_formats(f);

         else

             ret = ff_default_query_formats(f);
         if (ret < 0 && ret != AVERROR(EAGAIN))

             return ret;

         /* note: EAGAIN could indicate a partial success, not counted yet */
         count_queried += ret >= 0;

     }

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

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

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

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

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

             int convert_needed = 0;
 
             if (!link)
                 continue;
 

             if (link->in_formats != link->out_formats
                 && link->in_formats && link->out_formats)
                 if (!can_merge_formats(link->in_formats, link->out_formats,
                                       link->type, 0))
                     convert_needed = 1;
             if (link->type == AVMEDIA_TYPE_AUDIO) {
                 if (link->in_samplerates != link->out_samplerates
                     && link->in_samplerates && link->out_samplerates)
                     if (!can_merge_formats(link->in_samplerates,
                                            link->out_samplerates,
                                            0, 1))
                         convert_needed = 1;
             }
 

 #define MERGE_DISPATCH(field, statement)                                     \
             if (!(link->in_ ## field && link->out_ ## field)) {              \
                 count_delayed++;                                             \
             } else if (link->in_ ## field == link->out_ ## field) {          \
                 count_already_merged++;                                      \

             } else if (!convert_needed) {                                    \

                 count_merged++;                                              \
                 statement                                                    \
             }

             if (link->type == AVMEDIA_TYPE_AUDIO) {
                 MERGE_DISPATCH(channel_layouts,
                     if (!ff_merge_channel_layouts(link->in_channel_layouts,
                                                   link->out_channel_layouts))
                         convert_needed = 1;
                 )
                 MERGE_DISPATCH(samplerates,
                     if (!ff_merge_samplerates(link->in_samplerates,
                                               link->out_samplerates))
                         convert_needed = 1;
                 )

             }

             MERGE_DISPATCH(formats,
                 if (!ff_merge_formats(link->in_formats, link->out_formats,
                                       link->type))
                     convert_needed = 1;
             )

 #undef MERGE_DISPATCH

 
             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++);

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

                                                             inst_name, graph->scale_sws_opts, 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++);

                     scale_args[0] = '\0';

                     if (graph->aresample_swr_opts)

                         snprintf(scale_args, sizeof(scale_args), "%s",

                                  graph->aresample_swr_opts);

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

                                                             inst_name, graph->aresample_swr_opts,

                                                             NULL, graph)) < 0)

                         return ret;

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

                 if ((ret = filter_query_formats(convert)) < 0)
                     return ret;
 

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

                 av_assert0( inlink-> in_formats->refcount > 0);
                 av_assert0( inlink->out_formats->refcount > 0);
                 av_assert0(outlink-> in_formats->refcount > 0);
                 av_assert0(outlink->out_formats->refcount > 0);
                 if (outlink->type == AVMEDIA_TYPE_AUDIO) {
                     av_assert0( inlink-> in_samplerates->refcount > 0);
                     av_assert0( inlink->out_samplerates->refcount > 0);
                     av_assert0(outlink-> in_samplerates->refcount > 0);
                     av_assert0(outlink->out_samplerates->refcount > 0);
                     av_assert0( inlink-> in_channel_layouts->refcount > 0);
                     av_assert0( inlink->out_channel_layouts->refcount > 0);
                     av_assert0(outlink-> in_channel_layouts->refcount > 0);
                     av_assert0(outlink->out_channel_layouts->refcount > 0);
                 }

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

                     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;
                 }

             }
         }
     }
 

     av_log(graph, AV_LOG_DEBUG, "query_formats: "
            "%d queried, %d merged, %d already done, %d delayed\n",
            count_queried, count_merged, count_already_merged, count_delayed);
     if (count_delayed) {
         AVBPrint bp;
 

         /* if count_queried > 0, one filter at least did set its formats,
            that will give additional information to its neighbour;
            if count_merged > 0, one pair of formats lists at least was merged,
            that will give additional information to all connected filters;
            in both cases, progress was made and a new round must be done */

         if (count_queried || count_merged)
             return AVERROR(EAGAIN);
         av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
         for (i = 0; i < graph->nb_filters; i++)
             if (!formats_declared(graph->filters[i]))
                 av_bprintf(&bp, "%s%s", bp.len ? ", " : "",
                           graph->filters[i]->name);
         av_log(graph, AV_LOG_ERROR,
                "The following filters could not choose their formats: %s\n"
                "Consider inserting the (a)format filter near their input or "
                "output.\n", bp.str);
         return AVERROR(EIO);
     }

     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_desc_get(ref->format)->nb_components % 2 == 0;

             enum AVPixelFormat best= AV_PIX_FMT_NONE;

             int i;

             for (i=0; i<link->in_formats->nb_formats; i++) {

                 enum AVPixelFormat p = link->in_formats->formats[i];

                 best= av_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->nb_formats,

                    av_get_pix_fmt_name(ref->format), has_alpha);

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

     }
 

     link->in_formats->nb_formats = 1;

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

 
     if (link->type == AVMEDIA_TYPE_AUDIO) {

         if (!link->in_samplerates->nb_formats) {

             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->nb_formats = 1;

         link->sample_rate = link->in_samplerates->formats[0];
 

         if (link->in_channel_layouts->all_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);

             if (!link->in_channel_layouts->all_counts)
                 av_log(link->src, AV_LOG_ERROR, "Unknown channel layouts not "
                        "supported, try specifying a channel layout using "
                        "'aformat=channel_layouts=something'.\n");

             return AVERROR(EINVAL);
         }
         link->in_channel_layouts->nb_channel_layouts = 1;
         link->channel_layout = link->in_channel_layouts->channel_layouts[0];

         if ((link->channels = FF_LAYOUT2COUNT(link->channel_layout)))
             link->channel_layout = 0;
         else
             link->channels = av_get_channel_layout_nb_channels(link->channel_layout);

     }

     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);                \

                 ret = 1;                                               \

                 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,

                    nb_formats, ff_add_format);

     REDUCE_FORMATS(int,      AVFilterFormats,        samplerates,     formats,

                    nb_formats, ff_add_format);

 
     /* reduce channel layouts */
     for (i = 0; i < filter->nb_inputs; i++) {
         AVFilterLink *inlink = filter->inputs[i];
         uint64_t fmt;
 
         if (!inlink->out_channel_layouts ||
             inlink->out_channel_layouts->nb_channel_layouts != 1)
             continue;
         fmt = inlink->out_channel_layouts->channel_layouts[0];
 
         for (j = 0; j < filter->nb_outputs; j++) {
             AVFilterLink *outlink = filter->outputs[j];
             AVFilterChannelLayouts *fmts;
 
             fmts = outlink->in_channel_layouts;
             if (inlink->type != outlink->type || fmts->nb_channel_layouts == 1)
                 continue;
 

             if (fmts->all_layouts &&
                 (!FF_LAYOUT2COUNT(fmt) || fmts->all_counts)) {

                 /* Turn the infinite list into a singleton */
                 fmts->all_layouts = fmts->all_counts  = 0;
                 ff_add_channel_layout(&outlink->in_channel_layouts, fmt);
                 break;
             }
 
             for (k = 0; k < outlink->in_channel_layouts->nb_channel_layouts; k++) {
                 if (fmts->channel_layouts[k] == fmt) {
                     fmts->channel_layouts[0]  = fmt;
                     fmts->nb_channel_layouts = 1;
                     ret = 1;
                     break;
                 }
             }
         }
     }

 
     return ret;
 }
 
 static void reduce_formats(AVFilterGraph *graph)
 {
     int i, reduced;
 
     do {
         reduced = 0;
 

         for (i = 0; i < graph->nb_filters; 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->nb_formats== 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->nb_formats < 2)

             continue;
 

         for (j = 0; j < outlink->in_samplerates->nb_formats; 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->nb_filters; 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 = 100000;
 
             if (FF_LAYOUT2COUNT(in_chlayout) || FF_LAYOUT2COUNT(out_chlayout)) {
                 /* Compute score in case the input or output layout encodes
                    a channel count; in this case the score is not altered by
                    the computation afterwards, as in_chlayout and
                    out_chlayout have both been set to 0 */
                 if (FF_LAYOUT2COUNT(in_chlayout))
                     in_channels = FF_LAYOUT2COUNT(in_chlayout);
                 if (FF_LAYOUT2COUNT(out_chlayout))
                     out_channels = FF_LAYOUT2COUNT(out_chlayout);
                 score -= 10000 + FFABS(out_channels - in_channels) +
                          (in_channels > out_channels ? 10000 : 0);
                 in_chlayout = out_chlayout = 0;
                 /* Let the remaining computation run, even if the score
                    value is not altered */
             }

 
             /* 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->nb_filters; 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->nb_formats == 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->nb_formats < 2)

             continue;
 

         for (j = 0; j < outlink->in_formats->nb_formats; 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->nb_filters; 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->nb_filters; 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->nb_formats == 1) {

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

                         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->nb_formats == 1) {

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

                         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) {

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

                         change = 1;
                     }
                 }
             }

         }

     }while(change);
 

     for (i = 0; i < graph->nb_filters; 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 */

     while ((ret = query_formats(graph, log_ctx)) == AVERROR(EAGAIN))
         av_log(graph, AV_LOG_DEBUG, "query_formats not finished\n");
     if (ret < 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->nb_filters; 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->nb_filters; 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->nb_filters; 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->nb_filters; 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->nb_filters; i++) {

         AVFilterContext *filter = graph->filters[i];
         if(filter && (!strcmp(target, "all") || !strcmp(target, filter->name) || !strcmp(target, filter->filter->name))){

             AVFilterCommand **queue = &filter->command_queue, *next;
             while (*queue && (*queue)->time <= ts)
                 queue = &(*queue)->next;
             next = *queue;
             *queue = av_mallocz(sizeof(AVFilterCommand));
             (*queue)->command = av_strdup(command);
             (*queue)->arg     = av_strdup(arg);
             (*queue)->time    = ts;
             (*queue)->flags   = flags;
             (*queue)->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;
 }