text: /*
   * ffmpeg filter configuration
   *
   * 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 <stdint.h>
  
  #include "ffmpeg.h"
  
  #include "libavfilter/avfilter.h"
  #include "libavfilter/buffersink.h"
  #include "libavfilter/buffersrc.h"
  
  #include "libavutil/avassert.h"
  #include "libavutil/avstring.h"
  #include "libavutil/bprint.h"
  #include "libavutil/channel_layout.h"
  #include "libavutil/display.h"
  #include "libavutil/opt.h"
  #include "libavutil/pixdesc.h"
  #include "libavutil/pixfmt.h"
  #include "libavutil/imgutils.h"
  #include "libavutil/samplefmt.h"
  
  // FIXME: YUV420P etc. are actually supported with full color range,
  // yet the latter information isn't available here.
  static const enum AVPixelFormat *get_compliance_normal_pix_fmts(const AVCodec *codec, const enum AVPixelFormat default_formats[])
  {
      static const enum AVPixelFormat mjpeg_formats[] =
          { AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P,
            AV_PIX_FMT_NONE };
  
      if (!strcmp(codec->name, "mjpeg")) {
          return mjpeg_formats;
      } else {
          return default_formats;
      }
  }
  
  static enum AVPixelFormat choose_pixel_fmt(AVStream *st, AVCodecContext *enc_ctx,
                                      const AVCodec *codec, enum AVPixelFormat target)
  {
      if (codec && codec->pix_fmts) {
          const enum AVPixelFormat *p = codec->pix_fmts;
          const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(target);
          //FIXME: This should check for AV_PIX_FMT_FLAG_ALPHA after PAL8 pixel format without alpha is implemented
          int has_alpha = desc ? desc->nb_components % 2 == 0 : 0;
          enum AVPixelFormat best= AV_PIX_FMT_NONE;
  
          if (enc_ctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
              p = get_compliance_normal_pix_fmts(codec, p);
          }
          for (; *p != AV_PIX_FMT_NONE; p++) {
              best = av_find_best_pix_fmt_of_2(best, *p, target, has_alpha, NULL);
              if (*p == target)
                  break;
          }
          if (*p == AV_PIX_FMT_NONE) {
              if (target != AV_PIX_FMT_NONE)
                  av_log(NULL, AV_LOG_WARNING,
                         "Incompatible pixel format '%s' for codec '%s', auto-selecting format '%s'\n",
                         av_get_pix_fmt_name(target),
                         codec->name,
                         av_get_pix_fmt_name(best));
              return best;
          }
      }
      return target;
  }
  
  static char *choose_pix_fmts(OutputFilter *ofilter)
  {
      OutputStream *ost = ofilter->ost;
      AVDictionaryEntry *strict_dict = av_dict_get(ost->encoder_opts, "strict", NULL, 0);
      if (strict_dict)
          // used by choose_pixel_fmt() and below
          av_opt_set(ost->enc_ctx, "strict", strict_dict->value, 0);
  
       if (ost->keep_pix_fmt) {
          avfilter_graph_set_auto_convert(ofilter->graph->graph,
                                              AVFILTER_AUTO_CONVERT_NONE);
          if (ost->enc_ctx->pix_fmt == AV_PIX_FMT_NONE)
              return NULL;
          return av_strdup(av_get_pix_fmt_name(ost->enc_ctx->pix_fmt));
      }
      if (ost->enc_ctx->pix_fmt != AV_PIX_FMT_NONE) {
          return av_strdup(av_get_pix_fmt_name(choose_pixel_fmt(ost->st, ost->enc_ctx, ost->enc, ost->enc_ctx->pix_fmt)));
      } else if (ost->enc && ost->enc->pix_fmts) {
          const enum AVPixelFormat *p;
          AVIOContext *s = NULL;
          uint8_t *ret;
          int len;
  
          if (avio_open_dyn_buf(&s) < 0)
              exit_program(1);
  
          p = ost->enc->pix_fmts;
          if (ost->enc_ctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
              p = get_compliance_normal_pix_fmts(ost->enc, p);
          }
  
          for (; *p != AV_PIX_FMT_NONE; p++) {
              const char *name = av_get_pix_fmt_name(*p);
              avio_printf(s, "%s|", name);
          }
          len = avio_close_dyn_buf(s, &ret);
          ret[len - 1] = 0;
          return ret;
      } else
          return NULL;
  }
  
  /* Define a function for appending a list of allowed formats
   * to an AVBPrint. If nonempty, the list will have a header. */
  #define DEF_CHOOSE_FORMAT(name, type, var, supported_list, none, printf_format, get_name) \
  static void choose_ ## name (OutputFilter *ofilter, AVBPrint *bprint)          \
  {                                                                              \
      if (ofilter->var == none && !ofilter->supported_list)                      \
          return;                                                                \
      av_bprintf(bprint, #name "=");                                             \
      if (ofilter->var != none) {                                                \
          av_bprintf(bprint, printf_format, get_name(ofilter->var));             \
      } else {                                                                   \
          const type *p;                                                         \
                                                                                 \
          for (p = ofilter->supported_list; *p != none; p++) {                   \
              av_bprintf(bprint, printf_format "|", get_name(*p));               \
          }                                                                      \
          if (bprint->len > 0)                                                   \
              bprint->str[--bprint->len] = '\0';                                 \
      }                                                                          \
      av_bprint_chars(bprint, ':', 1);                                           \
  }
  
  //DEF_CHOOSE_FORMAT(pix_fmts, enum AVPixelFormat, format, formats, AV_PIX_FMT_NONE,
  //                  GET_PIX_FMT_NAME)
  
  DEF_CHOOSE_FORMAT(sample_fmts, enum AVSampleFormat, format, formats,
                    AV_SAMPLE_FMT_NONE, "%s", av_get_sample_fmt_name)
  
  DEF_CHOOSE_FORMAT(sample_rates, int, sample_rate, sample_rates, 0,
                    "%d", )
  
  DEF_CHOOSE_FORMAT(channel_layouts, uint64_t, channel_layout, channel_layouts, 0,
                    "0x%"PRIx64, )
  
  int init_simple_filtergraph(InputStream *ist, OutputStream *ost)
  {
      FilterGraph *fg = av_mallocz(sizeof(*fg));
  
      if (!fg)
          exit_program(1);
      fg->index = nb_filtergraphs;
  
      GROW_ARRAY(fg->outputs, fg->nb_outputs);
      if (!(fg->outputs[0] = av_mallocz(sizeof(*fg->outputs[0]))))
          exit_program(1);
      fg->outputs[0]->ost   = ost;
      fg->outputs[0]->graph = fg;
      fg->outputs[0]->format = -1;
  
      ost->filter = fg->outputs[0];
  
      GROW_ARRAY(fg->inputs, fg->nb_inputs);
      if (!(fg->inputs[0] = av_mallocz(sizeof(*fg->inputs[0]))))
          exit_program(1);
      fg->inputs[0]->ist   = ist;
      fg->inputs[0]->graph = fg;
      fg->inputs[0]->format = -1;
  
      fg->inputs[0]->frame_queue = av_fifo_alloc(8 * sizeof(AVFrame*));
      if (!fg->inputs[0]->frame_queue)
          exit_program(1);
  
      GROW_ARRAY(ist->filters, ist->nb_filters);
      ist->filters[ist->nb_filters - 1] = fg->inputs[0];
  
      GROW_ARRAY(filtergraphs, nb_filtergraphs);
      filtergraphs[nb_filtergraphs - 1] = fg;
  
      return 0;
  }
  
  static char *describe_filter_link(FilterGraph *fg, AVFilterInOut *inout, int in)
  {
      AVFilterContext *ctx = inout->filter_ctx;
      AVFilterPad *pads = in ? ctx->input_pads  : ctx->output_pads;
      int       nb_pads = in ? ctx->nb_inputs   : ctx->nb_outputs;
      AVIOContext *pb;
      uint8_t *res = NULL;
  
      if (avio_open_dyn_buf(&pb) < 0)
          exit_program(1);
  
      avio_printf(pb, "%s", ctx->filter->name);
      if (nb_pads > 1)
          avio_printf(pb, ":%s", avfilter_pad_get_name(pads, inout->pad_idx));
      avio_w8(pb, 0);
      avio_close_dyn_buf(pb, &res);
      return res;
  }
  
  static void init_input_filter(FilterGraph *fg, AVFilterInOut *in)
  {
      InputStream *ist = NULL;
      enum AVMediaType type = avfilter_pad_get_type(in->filter_ctx->input_pads, in->pad_idx);
      int i;
  
      // TODO: support other filter types
      if (type != AVMEDIA_TYPE_VIDEO && type != AVMEDIA_TYPE_AUDIO) {
          av_log(NULL, AV_LOG_FATAL, "Only video and audio filters supported "
                 "currently.\n");
          exit_program(1);
      }
  
      if (in->name) {
          AVFormatContext *s;
          AVStream       *st = NULL;
          char *p;
          int file_idx = strtol(in->name, &p, 0);
  
          if (file_idx < 0 || file_idx >= nb_input_files) {
              av_log(NULL, AV_LOG_FATAL, "Invalid file index %d in filtergraph description %s.\n",
                     file_idx, fg->graph_desc);
              exit_program(1);
          }
          s = input_files[file_idx]->ctx;
  
          for (i = 0; i < s->nb_streams; i++) {
              enum AVMediaType stream_type = s->streams[i]->codecpar->codec_type;
              if (stream_type != type &&
                  !(stream_type == AVMEDIA_TYPE_SUBTITLE &&
                    type == AVMEDIA_TYPE_VIDEO /* sub2video hack */))
                  continue;
              if (check_stream_specifier(s, s->streams[i], *p == ':' ? p + 1 : p) == 1) {
                  st = s->streams[i];
                  break;
              }
          }
          if (!st) {
              av_log(NULL, AV_LOG_FATAL, "Stream specifier '%s' in filtergraph description %s "
                     "matches no streams.\n", p, fg->graph_desc);
              exit_program(1);
          }
          ist = input_streams[input_files[file_idx]->ist_index + st->index];
          if (ist->user_set_discard == AVDISCARD_ALL) {
              av_log(NULL, AV_LOG_FATAL, "Stream specifier '%s' in filtergraph description %s "
                     "matches a disabled input stream.\n", p, fg->graph_desc);
              exit_program(1);
          }
      } else {
          /* find the first unused stream of corresponding type */
          for (i = 0; i < nb_input_streams; i++) {
              ist = input_streams[i];
              if (ist->user_set_discard == AVDISCARD_ALL)
                  continue;
              if (ist->dec_ctx->codec_type == type && ist->discard)
                  break;
          }
          if (i == nb_input_streams) {
              av_log(NULL, AV_LOG_FATAL, "Cannot find a matching stream for "
                     "unlabeled input pad %d on filter %s\n", in->pad_idx,
                     in->filter_ctx->name);
              exit_program(1);
          }
      }
      av_assert0(ist);
  
      ist->discard         = 0;
      ist->decoding_needed |= DECODING_FOR_FILTER;
      ist->st->discard = AVDISCARD_NONE;
  
      GROW_ARRAY(fg->inputs, fg->nb_inputs);
      if (!(fg->inputs[fg->nb_inputs - 1] = av_mallocz(sizeof(*fg->inputs[0]))))
          exit_program(1);
      fg->inputs[fg->nb_inputs - 1]->ist   = ist;
      fg->inputs[fg->nb_inputs - 1]->graph = fg;
      fg->inputs[fg->nb_inputs - 1]->format = -1;
      fg->inputs[fg->nb_inputs - 1]->type = ist->st->codecpar->codec_type;
      fg->inputs[fg->nb_inputs - 1]->name = describe_filter_link(fg, in, 1);
  
      fg->inputs[fg->nb_inputs - 1]->frame_queue = av_fifo_alloc(8 * sizeof(AVFrame*));
      if (!fg->inputs[fg->nb_inputs - 1]->frame_queue)
          exit_program(1);
  
      GROW_ARRAY(ist->filters, ist->nb_filters);
      ist->filters[ist->nb_filters - 1] = fg->inputs[fg->nb_inputs - 1];
  }
  
  int init_complex_filtergraph(FilterGraph *fg)
  {
      AVFilterInOut *inputs, *outputs, *cur;
      AVFilterGraph *graph;
      int ret = 0;
  
      /* this graph is only used for determining the kinds of inputs
       * and outputs we have, and is discarded on exit from this function */
      graph = avfilter_graph_alloc();
      if (!graph)
          return AVERROR(ENOMEM);
      graph->nb_threads = 1;
  
      ret = avfilter_graph_parse2(graph, fg->graph_desc, &inputs, &outputs);
      if (ret < 0)
          goto fail;
  
      for (cur = inputs; cur; cur = cur->next)
          init_input_filter(fg, cur);
  
      for (cur = outputs; cur;) {
          GROW_ARRAY(fg->outputs, fg->nb_outputs);
          fg->outputs[fg->nb_outputs - 1] = av_mallocz(sizeof(*fg->outputs[0]));
          if (!fg->outputs[fg->nb_outputs - 1])
              exit_program(1);
  
          fg->outputs[fg->nb_outputs - 1]->graph   = fg;
          fg->outputs[fg->nb_outputs - 1]->out_tmp = cur;
          fg->outputs[fg->nb_outputs - 1]->type    = avfilter_pad_get_type(cur->filter_ctx->output_pads,
                                                                           cur->pad_idx);
          fg->outputs[fg->nb_outputs - 1]->name = describe_filter_link(fg, cur, 0);
          cur = cur->next;
          fg->outputs[fg->nb_outputs - 1]->out_tmp->next = NULL;
      }
  
  fail:
      avfilter_inout_free(&inputs);
      avfilter_graph_free(&graph);
      return ret;
  }
  
  static int insert_trim(int64_t start_time, int64_t duration,
                         AVFilterContext **last_filter, int *pad_idx,
                         const char *filter_name)
  {
      AVFilterGraph *graph = (*last_filter)->graph;
      AVFilterContext *ctx;
      const AVFilter *trim;
      enum AVMediaType type = avfilter_pad_get_type((*last_filter)->output_pads, *pad_idx);
      const char *name = (type == AVMEDIA_TYPE_VIDEO) ? "trim" : "atrim";
      int ret = 0;
  
      if (duration == INT64_MAX && start_time == AV_NOPTS_VALUE)
          return 0;
  
      trim = avfilter_get_by_name(name);
      if (!trim) {
          av_log(NULL, AV_LOG_ERROR, "%s filter not present, cannot limit "
                 "recording time.\n", name);
          return AVERROR_FILTER_NOT_FOUND;
      }
  
      ctx = avfilter_graph_alloc_filter(graph, trim, filter_name);
      if (!ctx)
          return AVERROR(ENOMEM);
  
      if (duration != INT64_MAX) {
          ret = av_opt_set_int(ctx, "durationi", duration,
                                  AV_OPT_SEARCH_CHILDREN);
      }
      if (ret >= 0 && start_time != AV_NOPTS_VALUE) {
          ret = av_opt_set_int(ctx, "starti", start_time,
                                  AV_OPT_SEARCH_CHILDREN);
      }
      if (ret < 0) {
          av_log(ctx, AV_LOG_ERROR, "Error configuring the %s filter", name);
          return ret;
      }
  
      ret = avfilter_init_str(ctx, NULL);
      if (ret < 0)
          return ret;
  
      ret = avfilter_link(*last_filter, *pad_idx, ctx, 0);
      if (ret < 0)
          return ret;
  
      *last_filter = ctx;
      *pad_idx     = 0;
      return 0;
  }
  
  static int insert_filter(AVFilterContext **last_filter, int *pad_idx,
                           const char *filter_name, const char *args)
  {
      AVFilterGraph *graph = (*last_filter)->graph;
      AVFilterContext *ctx;
      int ret;
  
      ret = avfilter_graph_create_filter(&ctx,
                                         avfilter_get_by_name(filter_name),
                                         filter_name, args, NULL, graph);
      if (ret < 0)
          return ret;
  
      ret = avfilter_link(*last_filter, *pad_idx, ctx, 0);
      if (ret < 0)
          return ret;
  
      *last_filter = ctx;
      *pad_idx     = 0;
      return 0;
  }
  
  static int configure_output_video_filter(FilterGraph *fg, OutputFilter *ofilter, AVFilterInOut *out)
  {
      char *pix_fmts;
      OutputStream *ost = ofilter->ost;
      OutputFile    *of = output_files[ost->file_index];
      AVFilterContext *last_filter = out->filter_ctx;
      int pad_idx = out->pad_idx;
      int ret;
      char name[255];
  
      snprintf(name, sizeof(name), "out_%d_%d", ost->file_index, ost->index);
      ret = avfilter_graph_create_filter(&ofilter->filter,
                                         avfilter_get_by_name("buffersink"),
                                         name, NULL, NULL, fg->graph);
  
      if (ret < 0)
          return ret;
  
      if ((ofilter->width || ofilter->height) && ofilter->ost->autoscale) {
          char args[255];
          AVFilterContext *filter;
          AVDictionaryEntry *e = NULL;
  
          snprintf(args, sizeof(args), "%d:%d",
                   ofilter->width, ofilter->height);
  
          while ((e = av_dict_get(ost->sws_dict, "", e,
                                  AV_DICT_IGNORE_SUFFIX))) {
              av_strlcatf(args, sizeof(args), ":%s=%s", e->key, e->value);
          }
  
          snprintf(name, sizeof(name), "scaler_out_%d_%d",
                   ost->file_index, ost->index);
          if ((ret = avfilter_graph_create_filter(&filter, avfilter_get_by_name("scale"),
                                                  name, args, NULL, fg->graph)) < 0)
              return ret;
          if ((ret = avfilter_link(last_filter, pad_idx, filter, 0)) < 0)
              return ret;
  
          last_filter = filter;
          pad_idx = 0;
      }
  
      if ((pix_fmts = choose_pix_fmts(ofilter))) {
          AVFilterContext *filter;
  
          ret = avfilter_graph_create_filter(&filter,
                                             avfilter_get_by_name("format"),
                                             "format", pix_fmts, NULL, fg->graph);
          av_freep(&pix_fmts);
          if (ret < 0)
              return ret;
          if ((ret = avfilter_link(last_filter, pad_idx, filter, 0)) < 0)
              return ret;
  
          last_filter = filter;
          pad_idx     = 0;
      }
  
      if (ost->frame_rate.num && 0) {
          AVFilterContext *fps;
          char args[255];
  
          snprintf(args, sizeof(args), "fps=%d/%d", ost->frame_rate.num,
                   ost->frame_rate.den);
          snprintf(name, sizeof(name), "fps_out_%d_%d",
                   ost->file_index, ost->index);
          ret = avfilter_graph_create_filter(&fps, avfilter_get_by_name("fps"),
                                             name, args, NULL, fg->graph);
          if (ret < 0)
              return ret;
  
          ret = avfilter_link(last_filter, pad_idx, fps, 0);
          if (ret < 0)
              return ret;
          last_filter = fps;
          pad_idx = 0;
      }
  
      snprintf(name, sizeof(name), "trim_out_%d_%d",
               ost->file_index, ost->index);
      ret = insert_trim(of->start_time, of->recording_time,
                        &last_filter, &pad_idx, name);
      if (ret < 0)
          return ret;
  
  
      if ((ret = avfilter_link(last_filter, pad_idx, ofilter->filter, 0)) < 0)
          return ret;
  
      return 0;
  }
  
  static int configure_output_audio_filter(FilterGraph *fg, OutputFilter *ofilter, AVFilterInOut *out)
  {
      OutputStream *ost = ofilter->ost;
      OutputFile    *of = output_files[ost->file_index];
      AVCodecContext *codec  = ost->enc_ctx;
      AVFilterContext *last_filter = out->filter_ctx;
      int pad_idx = out->pad_idx;
      AVBPrint args;
      char name[255];
      int ret;
  
      snprintf(name, sizeof(name), "out_%d_%d", ost->file_index, ost->index);
      ret = avfilter_graph_create_filter(&ofilter->filter,
                                         avfilter_get_by_name("abuffersink"),
                                         name, NULL, NULL, fg->graph);
      if (ret < 0)
          return ret;
      if ((ret = av_opt_set_int(ofilter->filter, "all_channel_counts", 1, AV_OPT_SEARCH_CHILDREN)) < 0)
          return ret;
  
  #define AUTO_INSERT_FILTER(opt_name, filter_name, arg) do {                 \
      AVFilterContext *filt_ctx;                                              \
                                                                              \
      av_log(NULL, AV_LOG_INFO, opt_name " is forwarded to lavfi "            \
             "similarly to -af " filter_name "=%s.\n", arg);                  \
                                                                              \
      ret = avfilter_graph_create_filter(&filt_ctx,                           \
                                         avfilter_get_by_name(filter_name),   \
                                         filter_name, arg, NULL, fg->graph);  \
      if (ret < 0)                                                            \
          goto fail;                                                          \
                                                                              \
      ret = avfilter_link(last_filter, pad_idx, filt_ctx, 0);                 \
      if (ret < 0)                                                            \
          goto fail;                                                          \
                                                                              \
      last_filter = filt_ctx;                                                 \
      pad_idx = 0;                                                            \
  } while (0)
      av_bprint_init(&args, 0, AV_BPRINT_SIZE_UNLIMITED);
      if (ost->audio_channels_mapped) {
          int i;
          av_bprintf(&args, "0x%"PRIx64,
                     av_get_default_channel_layout(ost->audio_channels_mapped));
          for (i = 0; i < ost->audio_channels_mapped; i++)
              if (ost->audio_channels_map[i] != -1)
                  av_bprintf(&args, "|c%d=c%d", i, ost->audio_channels_map[i]);
  
          AUTO_INSERT_FILTER("-map_channel", "pan", args.str);
          av_bprint_clear(&args);
      }
  
      if (codec->channels && !codec->channel_layout)
          codec->channel_layout = av_get_default_channel_layout(codec->channels);
  
      choose_sample_fmts(ofilter,     &args);
      choose_sample_rates(ofilter,    &args);
      choose_channel_layouts(ofilter, &args);
      if (!av_bprint_is_complete(&args)) {
          ret = AVERROR(ENOMEM);
          goto fail;
      }
      if (args.len) {
          AVFilterContext *format;
  
          snprintf(name, sizeof(name), "format_out_%d_%d",
                   ost->file_index, ost->index);
          ret = avfilter_graph_create_filter(&format,
                                             avfilter_get_by_name("aformat"),
                                             name, args.str, NULL, fg->graph);
          if (ret < 0)
              goto fail;
  
          ret = avfilter_link(last_filter, pad_idx, format, 0);
          if (ret < 0)
              goto fail;
  
          last_filter = format;
          pad_idx = 0;
      }
  
      if (ost->apad && of->shortest) {
          int i;
  
          for (i=0; i<of->ctx->nb_streams; i++)
              if (of->ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
                  break;
  
          if (i<of->ctx->nb_streams) {
              AUTO_INSERT_FILTER("-apad", "apad", ost->apad);
          }
      }
  
      snprintf(name, sizeof(name), "trim for output stream %d:%d",
               ost->file_index, ost->index);
      ret = insert_trim(of->start_time, of->recording_time,
                        &last_filter, &pad_idx, name);
      if (ret < 0)
          goto fail;
  
      if ((ret = avfilter_link(last_filter, pad_idx, ofilter->filter, 0)) < 0)
          goto fail;
  fail:
      av_bprint_finalize(&args, NULL);
  
      return ret;
  }
  
  static int configure_output_filter(FilterGraph *fg, OutputFilter *ofilter,
                                     AVFilterInOut *out)
  {
      if (!ofilter->ost) {
          av_log(NULL, AV_LOG_FATAL, "Filter %s has an unconnected output\n", ofilter->name);
          exit_program(1);
      }
  
      switch (avfilter_pad_get_type(out->filter_ctx->output_pads, out->pad_idx)) {
      case AVMEDIA_TYPE_VIDEO: return configure_output_video_filter(fg, ofilter, out);
      case AVMEDIA_TYPE_AUDIO: return configure_output_audio_filter(fg, ofilter, out);
      default: av_assert0(0); return 0;
      }
  }
  
  void check_filter_outputs(void)
  {
      int i;
      for (i = 0; i < nb_filtergraphs; i++) {
          int n;
          for (n = 0; n < filtergraphs[i]->nb_outputs; n++) {
              OutputFilter *output = filtergraphs[i]->outputs[n];
              if (!output->ost) {
                  av_log(NULL, AV_LOG_FATAL, "Filter %s has an unconnected output\n", output->name);
                  exit_program(1);
              }
          }
      }
  }
  
  static int sub2video_prepare(InputStream *ist, InputFilter *ifilter)
  {
      AVFormatContext *avf = input_files[ist->file_index]->ctx;
      int i, w, h;
  
      /* Compute the size of the canvas for the subtitles stream.
         If the subtitles codecpar has set a size, use it. Otherwise use the
         maximum dimensions of the video streams in the same file. */
      w = ifilter->width;
      h = ifilter->height;
      if (!(w && h)) {
          for (i = 0; i < avf->nb_streams; i++) {
              if (avf->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
                  w = FFMAX(w, avf->streams[i]->codecpar->width);
                  h = FFMAX(h, avf->streams[i]->codecpar->height);
              }
          }
          if (!(w && h)) {
              w = FFMAX(w, 720);
              h = FFMAX(h, 576);
          }
          av_log(avf, AV_LOG_INFO, "sub2video: using %dx%d canvas\n", w, h);
      }
      ist->sub2video.w = ifilter->width  = w;
      ist->sub2video.h = ifilter->height = h;
  
      ifilter->width  = ist->dec_ctx->width  ? ist->dec_ctx->width  : ist->sub2video.w;
      ifilter->height = ist->dec_ctx->height ? ist->dec_ctx->height : ist->sub2video.h;
  
      /* rectangles are AV_PIX_FMT_PAL8, but we have no guarantee that the
         palettes for all rectangles are identical or compatible */
      ifilter->format = AV_PIX_FMT_RGB32;
  
      ist->sub2video.frame = av_frame_alloc();
      if (!ist->sub2video.frame)
          return AVERROR(ENOMEM);
      ist->sub2video.last_pts = INT64_MIN;
      ist->sub2video.end_pts  = INT64_MIN;
  
      /* sub2video structure has been (re-)initialized.
         Mark it as such so that the system will be
         initialized with the first received heartbeat. */
      ist->sub2video.initialize = 1;
  
      return 0;
  }
  
  static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter,
                                          AVFilterInOut *in)
  {
      AVFilterContext *last_filter;
      const AVFilter *buffer_filt = avfilter_get_by_name("buffer");
      const AVPixFmtDescriptor *desc;
      InputStream *ist = ifilter->ist;
      InputFile     *f = input_files[ist->file_index];
      AVRational tb = ist->framerate.num ? av_inv_q(ist->framerate) :
                                           ist->st->time_base;
      AVRational fr = ist->framerate;
      AVRational sar;
      AVBPrint args;
      char name[255];
      int ret, pad_idx = 0;
      int64_t tsoffset = 0;
      AVBufferSrcParameters *par = av_buffersrc_parameters_alloc();
  
      if (!par)
          return AVERROR(ENOMEM);
      memset(par, 0, sizeof(*par));
      par->format = AV_PIX_FMT_NONE;
  
      if (ist->dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
          av_log(NULL, AV_LOG_ERROR, "Cannot connect video filter to audio input\n");
          ret = AVERROR(EINVAL);
          goto fail;
      }
  
      if (!fr.num)
          fr = av_guess_frame_rate(input_files[ist->file_index]->ctx, ist->st, NULL);
  
      if (ist->dec_ctx->codec_type == AVMEDIA_TYPE_SUBTITLE) {
          ret = sub2video_prepare(ist, ifilter);
          if (ret < 0)
              goto fail;
      }
  
      sar = ifilter->sample_aspect_ratio;
      if(!sar.den)
          sar = (AVRational){0,1};
      av_bprint_init(&args, 0, AV_BPRINT_SIZE_AUTOMATIC);
      av_bprintf(&args,
               "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:"
               "pixel_aspect=%d/%d",
               ifilter->width, ifilter->height, ifilter->format,
               tb.num, tb.den, sar.num, sar.den);
      if (fr.num && fr.den)
          av_bprintf(&args, ":frame_rate=%d/%d", fr.num, fr.den);
      snprintf(name, sizeof(name), "graph %d input from stream %d:%d", fg->index,
               ist->file_index, ist->st->index);
  
  
      if ((ret = avfilter_graph_create_filter(&ifilter->filter, buffer_filt, name,
                                              args.str, NULL, fg->graph)) < 0)
          goto fail;
      par->hw_frames_ctx = ifilter->hw_frames_ctx;
      ret = av_buffersrc_parameters_set(ifilter->filter, par);
      if (ret < 0)
          goto fail;
      av_freep(&par);
      last_filter = ifilter->filter;
  
      desc = av_pix_fmt_desc_get(ifilter->format);
      av_assert0(desc);
  
      // TODO: insert hwaccel enabled filters like transpose_vaapi into the graph
      if (ist->autorotate && !(desc->flags & AV_PIX_FMT_FLAG_HWACCEL)) {
          int32_t *displaymatrix = ifilter->displaymatrix;
          double theta;
  
          if (!displaymatrix)
              displaymatrix = (int32_t *)av_stream_get_side_data(ist->st, AV_PKT_DATA_DISPLAYMATRIX, NULL);
          theta = get_rotation(displaymatrix);
  
          if (fabs(theta - 90) < 1.0) {
              if (displaymatrix[3] > 0) {
                  ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
                  if (ret < 0)
                      return ret;
              }
              ret = insert_filter(&last_filter, &pad_idx, "transpose", "clock");
          } else if (fabs(theta - 180) < 1.0) {
              if (displaymatrix[0] < 0) {
                  ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
                  if (ret < 0)
                      return ret;
              }
              if (displaymatrix[4] < 0) {
                  ret = insert_filter(&last_filter, &pad_idx, "vflip", NULL);
              }
          } else if (fabs(theta - 270) < 1.0) {
              if (displaymatrix[3] < 0) {
                  ret = insert_filter(&last_filter, &pad_idx, "hflip", NULL);
                  if (ret < 0)
                      return ret;
              }
              ret = insert_filter(&last_filter, &pad_idx, "transpose", "cclock");
          } else if (fabs(theta) > 1.0) {
              char rotate_buf[64];
              snprintf(rotate_buf, sizeof(rotate_buf), "%f*PI/180", theta);
              ret = insert_filter(&last_filter, &pad_idx, "rotate", rotate_buf);
          } else if (fabs(theta) < 1.0) {
              if (displaymatrix && displaymatrix[4] < 0) {
                  ret = insert_filter(&last_filter, &pad_idx, "vflip", NULL);
              }
          }
          if (ret < 0)
              return ret;
      }
  
      if (do_deinterlace) {
          AVFilterContext *yadif;
  
          snprintf(name, sizeof(name), "deinterlace_in_%d_%d",
                   ist->file_index, ist->st->index);
          if ((ret = avfilter_graph_create_filter(&yadif,
                                                  avfilter_get_by_name("yadif"),
                                                  name, "", NULL,
                                                  fg->graph)) < 0)
              return ret;
  
          if ((ret = avfilter_link(last_filter, 0, yadif, 0)) < 0)
              return ret;
  
          last_filter = yadif;
      }
  
      snprintf(name, sizeof(name), "trim_in_%d_%d",
               ist->file_index, ist->st->index);
      if (copy_ts) {
          tsoffset = f->start_time == AV_NOPTS_VALUE ? 0 : f->start_time;
          if (!start_at_zero && f->ctx->start_time != AV_NOPTS_VALUE)
              tsoffset += f->ctx->start_time;
      }
      ret = insert_trim(((f->start_time == AV_NOPTS_VALUE) || !f->accurate_seek) ?
                        AV_NOPTS_VALUE : tsoffset, f->recording_time,
                        &last_filter, &pad_idx, name);
      if (ret < 0)
          return ret;
  
      if ((ret = avfilter_link(last_filter, 0, in->filter_ctx, in->pad_idx)) < 0)
          return ret;
      return 0;
  fail:
      av_freep(&par);
  
      return ret;
  }
  
  static int configure_input_audio_filter(FilterGraph *fg, InputFilter *ifilter,
                                          AVFilterInOut *in)
  {
      AVFilterContext *last_filter;
      const AVFilter *abuffer_filt = avfilter_get_by_name("abuffer");
      InputStream *ist = ifilter->ist;
      InputFile     *f = input_files[ist->file_index];
      AVBPrint args;
      char name[255];
      int ret, pad_idx = 0;
      int64_t tsoffset = 0;
  
      if (ist->dec_ctx->codec_type != AVMEDIA_TYPE_AUDIO) {
          av_log(NULL, AV_LOG_ERROR, "Cannot connect audio filter to non audio input\n");
          return AVERROR(EINVAL);
      }
  
      av_bprint_init(&args, 0, AV_BPRINT_SIZE_AUTOMATIC);
      av_bprintf(&args, "time_base=%d/%d:sample_rate=%d:sample_fmt=%s",
               1, ifilter->sample_rate,
               ifilter->sample_rate,
               av_get_sample_fmt_name(ifilter->format));
      if (ifilter->channel_layout)
          av_bprintf(&args, ":channel_layout=0x%"PRIx64,
                     ifilter->channel_layout);
      else
          av_bprintf(&args, ":channels=%d", ifilter->channels);
      snprintf(name, sizeof(name), "graph_%d_in_%d_%d", fg->index,
               ist->file_index, ist->st->index);
  
      if ((ret = avfilter_graph_create_filter(&ifilter->filter, abuffer_filt,
                                              name, args.str, NULL,
                                              fg->graph)) < 0)
          return ret;
      last_filter = ifilter->filter;
  
  #define AUTO_INSERT_FILTER_INPUT(opt_name, filter_name, arg) do {                 \
      AVFilterContext *filt_ctx;                                              \
                                                                              \
      av_log(NULL, AV_LOG_INFO, opt_name " is forwarded to lavfi "            \
             "similarly to -af " filter_name "=%s.\n", arg);                  \
                                                                              \
      snprintf(name, sizeof(name), "graph_%d_%s_in_%d_%d",      \
                  fg->index, filter_name, ist->file_index, ist->st->index);   \
      ret = avfilter_graph_create_filter(&filt_ctx,                           \
                                         avfilter_get_by_name(filter_name),   \
                                         name, arg, NULL, fg->graph);         \
      if (ret < 0)                                                            \
          return ret;                                                         \
                                                                              \
      ret = avfilter_link(last_filter, 0, filt_ctx, 0);                       \
      if (ret < 0)                                                            \
          return ret;                                                         \
                                                                              \
      last_filter = filt_ctx;                                                 \
  } while (0)
  
      if (audio_sync_method > 0) {
          char args[256] = {0};
  
          av_strlcatf(args, sizeof(args), "async=%d", audio_sync_method);
          if (audio_drift_threshold != 0.1)
              av_strlcatf(args, sizeof(args), ":min_hard_comp=%f", audio_drift_threshold);
          if (!fg->reconfiguration)
              av_strlcatf(args, sizeof(args), ":first_pts=0");
          AUTO_INSERT_FILTER_INPUT("-async", "aresample", args);
      }
  
  //     if (ost->audio_channels_mapped) {
  //         int i;
  //         AVBPrint pan_buf;
  //         av_bprint_init(&pan_buf, 256, 8192);
  //         av_bprintf(&pan_buf, "0x%"PRIx64,
  //                    av_get_default_channel_layout(ost->audio_channels_mapped));
  //         for (i = 0; i < ost->audio_channels_mapped; i++)
  //             if (ost->audio_channels_map[i] != -1)
  //                 av_bprintf(&pan_buf, ":c%d=c%d", i, ost->audio_channels_map[i]);
  //         AUTO_INSERT_FILTER_INPUT("-map_channel", "pan", pan_buf.str);
  //         av_bprint_finalize(&pan_buf, NULL);
  //     }
  
      if (audio_volume != 256) {
          char args[256];
  
          av_log(NULL, AV_LOG_WARNING, "-vol has been deprecated. Use the volume "
                 "audio filter instead.\n");
  
          snprintf(args, sizeof(args), "%f", audio_volume / 256.);
          AUTO_INSERT_FILTER_INPUT("-vol", "volume", args);
      }
  
      snprintf(name, sizeof(name), "trim for input stream %d:%d",
               ist->file_index, ist->st->index);
      if (copy_ts) {
          tsoffset = f->start_time == AV_NOPTS_VALUE ? 0 : f->start_time;
          if (!start_at_zero && f->ctx->start_time != AV_NOPTS_VALUE)
              tsoffset += f->ctx->start_time;
      }
      ret = insert_trim(((f->start_time == AV_NOPTS_VALUE) || !f->accurate_seek) ?
                        AV_NOPTS_VALUE : tsoffset, f->recording_time,
                        &last_filter, &pad_idx, name);
      if (ret < 0)
          return ret;
  
      if ((ret = avfilter_link(last_filter, 0, in->filter_ctx, in->pad_idx)) < 0)
          return ret;
  
      return 0;
  }
  
  static int configure_input_filter(FilterGraph *fg, InputFilter *ifilter,
                                    AVFilterInOut *in)
  {
      if (!ifilter->ist->dec) {
          av_log(NULL, AV_LOG_ERROR,
                 "No decoder for stream #%d:%d, filtering impossible\n",
                 ifilter->ist->file_index, ifilter->ist->st->index);
          return AVERROR_DECODER_NOT_FOUND;
      }
      switch (avfilter_pad_get_type(in->filter_ctx->input_pads, in->pad_idx)) {
      case AVMEDIA_TYPE_VIDEO: return configure_input_video_filter(fg, ifilter, in);
      case AVMEDIA_TYPE_AUDIO: return configure_input_audio_filter(fg, ifilter, in);
      default: av_assert0(0); return 0;
      }
  }
  
  static void cleanup_filtergraph(FilterGraph *fg)
  {
      int i;
      for (i = 0; i < fg->nb_outputs; i++)
          fg->outputs[i]->filter = (AVFilterContext *)NULL;
      for (i = 0; i < fg->nb_inputs; i++)
          fg->inputs[i]->filter = (AVFilterContext *)NULL;
      avfilter_graph_free(&fg->graph);
  }
  
  int configure_filtergraph(FilterGraph *fg)
  {
      AVFilterInOut *inputs, *outputs, *cur;
      int ret, i, simple = filtergraph_is_simple(fg);
      const char *graph_desc = simple ? fg->outputs[0]->ost->avfilter :
                                        fg->graph_desc;
  
      cleanup_filtergraph(fg);
      if (!(fg->graph = avfilter_graph_alloc()))
          return AVERROR(ENOMEM);
  
      if (simple) {
          OutputStream *ost = fg->outputs[0]->ost;
          char args[512];
          AVDictionaryEntry *e = NULL;
  
          if (filter_nbthreads) {
              ret = av_opt_set(fg->graph, "threads", filter_nbthreads, 0);
              if (ret < 0)
                  goto fail;
          } else {
              e = av_dict_get(ost->encoder_opts, "threads", NULL, 0);
              if (e)
                  av_opt_set(fg->graph, "threads", e->value, 0);
          }
  
          args[0] = 0;
          e       = NULL;
          while ((e = av_dict_get(ost->sws_dict, "", e,
                                  AV_DICT_IGNORE_SUFFIX))) {
              av_strlcatf(args, sizeof(args), "%s=%s:", e->key, e->value);
          }
          if (strlen(args)) {
              args[strlen(args)-1] = 0;
              fg->graph->scale_sws_opts = av_strdup(args);
          }
  
          args[0] = 0;
          e       = NULL;
          while ((e = av_dict_get(ost->swr_opts, "", e,
                                  AV_DICT_IGNORE_SUFFIX))) {
              av_strlcatf(args, sizeof(args), "%s=%s:", e->key, e->value);
          }
          if (strlen(args))
              args[strlen(args)-1] = 0;
          av_opt_set(fg->graph, "aresample_swr_opts", args, 0);
      } else {
          fg->graph->nb_threads = filter_complex_nbthreads;
      }
  
      if ((ret = avfilter_graph_parse2(fg->graph, graph_desc, &inputs, &outputs)) < 0)
          goto fail;
  
      ret = hw_device_setup_for_filter(fg);
      if (ret < 0)
          goto fail;
  
      if (simple && (!inputs || inputs->next || !outputs || outputs->next)) {
          const char *num_inputs;
          const char *num_outputs;
          if (!outputs) {
              num_outputs = "0";
          } else if (outputs->next) {
              num_outputs = ">1";
          } else {
              num_outputs = "1";
          }
          if (!inputs) {
              num_inputs = "0";
          } else if (inputs->next) {
              num_inputs = ">1";
          } else {
              num_inputs = "1";
          }
          av_log(NULL, AV_LOG_ERROR, "Simple filtergraph '%s' was expected "
                 "to have exactly 1 input and 1 output."
                 " However, it had %s input(s) and %s output(s)."
                 " Please adjust, or use a complex filtergraph (-filter_complex) instead.\n",
                 graph_desc, num_inputs, num_outputs);
          ret = AVERROR(EINVAL);
          goto fail;
      }
  
      for (cur = inputs, i = 0; cur; cur = cur->next, i++)
          if ((ret = configure_input_filter(fg, fg->inputs[i], cur)) < 0) {
              avfilter_inout_free(&inputs);
              avfilter_inout_free(&outputs);
              goto fail;
          }
      avfilter_inout_free(&inputs);
  
      for (cur = outputs, i = 0; cur; cur = cur->next, i++)
          configure_output_filter(fg, fg->outputs[i], cur);
      avfilter_inout_free(&outputs);
  
      if (!auto_conversion_filters)
          avfilter_graph_set_auto_convert(fg->graph, AVFILTER_AUTO_CONVERT_NONE);
      if ((ret = avfilter_graph_config(fg->graph, NULL)) < 0)
          goto fail;
  
      /* limit the lists of allowed formats to the ones selected, to
       * make sure they stay the same if the filtergraph is reconfigured later */
      for (i = 0; i < fg->nb_outputs; i++) {
          OutputFilter *ofilter = fg->outputs[i];
          AVFilterContext *sink = ofilter->filter;
  
          ofilter->format = av_buffersink_get_format(sink);
  
          ofilter->width  = av_buffersink_get_w(sink);
          ofilter->height = av_buffersink_get_h(sink);
  
          ofilter->sample_rate    = av_buffersink_get_sample_rate(sink);
          ofilter->channel_layout = av_buffersink_get_channel_layout(sink);
      }
  
      fg->reconfiguration = 1;
  
      for (i = 0; i < fg->nb_outputs; i++) {
          OutputStream *ost = fg->outputs[i]->ost;
          if (!ost->enc) {
              /* identical to the same check in ffmpeg.c, needed because
                 complex filter graphs are initialized earlier */
              av_log(NULL, AV_LOG_ERROR, "Encoder (codec %s) not found for output stream #%d:%d\n",
                       avcodec_get_name(ost->st->codecpar->codec_id), ost->file_index, ost->index);
              ret = AVERROR(EINVAL);
              goto fail;
          }
          if (ost->enc->type == AVMEDIA_TYPE_AUDIO &&
              !(ost->enc->capabilities & AV_CODEC_CAP_VARIABLE_FRAME_SIZE))
              av_buffersink_set_frame_size(ost->filter->filter,
                                           ost->enc_ctx->frame_size);
      }
  
      for (i = 0; i < fg->nb_inputs; i++) {
          while (av_fifo_size(fg->inputs[i]->frame_queue)) {
              AVFrame *tmp;
              av_fifo_generic_read(fg->inputs[i]->frame_queue, &tmp, sizeof(tmp), NULL);
              ret = av_buffersrc_add_frame(fg->inputs[i]->filter, tmp);
              av_frame_free(&tmp);
              if (ret < 0)
                  goto fail;
          }
      }
  
      /* send the EOFs for the finished inputs */
      for (i = 0; i < fg->nb_inputs; i++) {
          if (fg->inputs[i]->eof) {
              ret = av_buffersrc_add_frame(fg->inputs[i]->filter, NULL);
              if (ret < 0)
                  goto fail;
          }
      }
  
      /* process queued up subtitle packets */
      for (i = 0; i < fg->nb_inputs; i++) {
          InputStream *ist = fg->inputs[i]->ist;
          if (ist->sub2video.sub_queue && ist->sub2video.frame) {
              while (av_fifo_size(ist->sub2video.sub_queue)) {
                  AVSubtitle tmp;
                  av_fifo_generic_read(ist->sub2video.sub_queue, &tmp, sizeof(tmp), NULL);
                  sub2video_update(ist, INT64_MIN, &tmp);
                  avsubtitle_free(&tmp);
              }
          }
      }
  
      return 0;
  
  fail:
      cleanup_filtergraph(fg);
      return ret;
  }
  
  int ifilter_parameters_from_frame(InputFilter *ifilter, const AVFrame *frame)
  {
      AVFrameSideData *sd;
  
      av_buffer_unref(&ifilter->hw_frames_ctx);
  
      ifilter->format = frame->format;
  
      ifilter->width               = frame->width;
      ifilter->height              = frame->height;
      ifilter->sample_aspect_ratio = frame->sample_aspect_ratio;
  
      ifilter->sample_rate         = frame->sample_rate;
      ifilter->channels            = frame->channels;
      ifilter->channel_layout      = frame->channel_layout;
  
      av_freep(&ifilter->displaymatrix);
      sd = av_frame_get_side_data(frame, AV_FRAME_DATA_DISPLAYMATRIX);
      if (sd)
          ifilter->displaymatrix = av_memdup(sd->data, sizeof(int32_t) * 9);
  
      if (frame->hw_frames_ctx) {
          ifilter->hw_frames_ctx = av_buffer_ref(frame->hw_frames_ctx);
          if (!ifilter->hw_frames_ctx)
              return AVERROR(ENOMEM);
      }
  
      return 0;
  }
  
  int filtergraph_is_simple(FilterGraph *fg)
  {
      return !fg->graph_desc;
  }
  