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 "ffmpeg.h"
  
  #include "libavfilter/avfilter.h"
  #include "libavfilter/buffersink.h"
  
  #include "libavresample/avresample.h"
  
  #include "libavutil/avassert.h"
  #include "libavutil/avstring.h"
  #include "libavutil/bprint.h"
  #include "libavutil/channel_layout.h"
  #include "libavutil/opt.h"
  #include "libavutil/pixdesc.h"
  #include "libavutil/pixfmt.h"
  #include "libavutil/imgutils.h"
  #include "libavutil/samplefmt.h"
  
  enum AVPixelFormat choose_pixel_fmt(AVStream *st, 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);
          int has_alpha = desc ? desc->nb_components % 2 == 0 : 0;
          enum AVPixelFormat best= AV_PIX_FMT_NONE;
          if (st->codec->strict_std_compliance <= FF_COMPLIANCE_UNOFFICIAL) {
              if (st->codec->codec_id == AV_CODEC_ID_MJPEG) {
                  p = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_NONE };
              } else if (st->codec->codec_id == AV_CODEC_ID_LJPEG) {
                  p = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUV420P,
                                                   AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_BGRA, AV_PIX_FMT_NONE };
              }
          }
          for (; *p != AV_PIX_FMT_NONE; p++) {
              best= avcodec_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;
  }
  
  void choose_sample_fmt(AVStream *st, AVCodec *codec)
  {
      if (codec && codec->sample_fmts) {
          const enum AVSampleFormat *p = codec->sample_fmts;
          for (; *p != -1; p++) {
              if (*p == st->codec->sample_fmt)
                  break;
          }
          if (*p == -1) {
              if((codec->capabilities & CODEC_CAP_LOSSLESS) && av_get_sample_fmt_name(st->codec->sample_fmt) > av_get_sample_fmt_name(codec->sample_fmts[0]))
                  av_log(NULL, AV_LOG_ERROR, "Conversion will not be lossless.\n");
              if(av_get_sample_fmt_name(st->codec->sample_fmt))
              av_log(NULL, AV_LOG_WARNING,
                     "Incompatible sample format '%s' for codec '%s', auto-selecting format '%s'\n",
                     av_get_sample_fmt_name(st->codec->sample_fmt),
                     codec->name,
                     av_get_sample_fmt_name(codec->sample_fmts[0]));
              st->codec->sample_fmt = codec->sample_fmts[0];
          }
      }
  }
  
  static char *choose_pix_fmts(OutputStream *ost)
  {
       if (ost->keep_pix_fmt) {
          if (ost->filter)
              avfilter_graph_set_auto_convert(ost->filter->graph->graph,
                                              AVFILTER_AUTO_CONVERT_NONE);
          if (ost->st->codec->pix_fmt == AV_PIX_FMT_NONE)
              return NULL;
          return av_strdup(av_get_pix_fmt_name(ost->st->codec->pix_fmt));
      }
      if (ost->st->codec->pix_fmt != AV_PIX_FMT_NONE) {
          return av_strdup(av_get_pix_fmt_name(choose_pixel_fmt(ost->st, ost->enc, ost->st->codec->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->st->codec->strict_std_compliance <= FF_COMPLIANCE_UNOFFICIAL) {
              if (ost->st->codec->codec_id == AV_CODEC_ID_MJPEG) {
                  p = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_NONE };
              } else if (ost->st->codec->codec_id == AV_CODEC_ID_LJPEG) {
                  p = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUV420P,
                                                      AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_BGRA, AV_PIX_FMT_NONE };
              }
          }
  
          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 building a string containing a list of
   * allowed formats. */
  #define DEF_CHOOSE_FORMAT(type, var, supported_list, none, get_name)           \
  static char *choose_ ## var ## s(OutputStream *ost)                            \
  {                                                                              \
      if (ost->st->codec->var != none) {                                         \
          get_name(ost->st->codec->var);                                         \
          return av_strdup(name);                                                \
      } else if (ost->enc && ost->enc->supported_list) {                         \
          const type *p;                                                         \
          AVIOContext *s = NULL;                                                 \
          uint8_t *ret;                                                          \
          int len;                                                               \
                                                                                 \
          if (avio_open_dyn_buf(&s) < 0)                                         \
              exit_program(1);                                                           \
                                                                                 \
          for (p = ost->enc->supported_list; *p != none; p++) {                  \
              get_name(*p);                                                      \
              avio_printf(s, "%s|", name);                                       \
          }                                                                      \
          len = avio_close_dyn_buf(s, &ret);                                     \
          ret[len - 1] = 0;                                                      \
          return ret;                                                            \
      } else                                                                     \
          return NULL;                                                           \
  }
  
  // DEF_CHOOSE_FORMAT(enum AVPixelFormat, pix_fmt, pix_fmts, AV_PIX_FMT_NONE,
  //                   GET_PIX_FMT_NAME)
  
  DEF_CHOOSE_FORMAT(enum AVSampleFormat, sample_fmt, sample_fmts,
                    AV_SAMPLE_FMT_NONE, GET_SAMPLE_FMT_NAME)
  
  DEF_CHOOSE_FORMAT(int, sample_rate, supported_samplerates, 0,
                    GET_SAMPLE_RATE_NAME)
  
  DEF_CHOOSE_FORMAT(uint64_t, channel_layout, channel_layouts, 0,
                    GET_CH_LAYOUT_NAME)
  
  FilterGraph *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;
  
      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;
  
      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 fg;
  }
  
  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]->codec->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];
      } else {
          /* find the first unused stream of corresponding type */
          for (i = 0; i < nb_input_streams; i++) {
              ist = input_streams[i];
              if (ist->st->codec->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++;
      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;
  
      GROW_ARRAY(ist->filters, ist->nb_filters);
      ist->filters[ist->nb_filters - 1] = fg->inputs[fg->nb_inputs - 1];
  }
  
  static int insert_trim(OutputStream *ost, AVFilterContext **last_filter, int *pad_idx)
  {
      OutputFile *of = output_files[ost->file_index];
      AVFilterGraph *graph = (*last_filter)->graph;
      AVFilterContext *ctx;
      const AVFilter *trim;
      const char *name = ost->st->codec->codec_type == AVMEDIA_TYPE_VIDEO ? "trim" : "atrim";
      char filter_name[128];
      int ret = 0;
  
      if (of->recording_time == INT64_MAX && !of->start_time)
          return 0;
  
      // Use with duration and without output starttime is buggy with trim filters
      if (!of->start_time)
          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;
      }
  
      snprintf(filter_name, sizeof(filter_name), "%s for output stream %d:%d",
               name, ost->file_index, ost->index);
      ctx = avfilter_graph_alloc_filter(graph, trim, filter_name);
      if (!ctx)
          return AVERROR(ENOMEM);
  
      if (of->recording_time != INT64_MAX) {
          ret = av_opt_set_double(ctx, "duration", (double)of->recording_time / 1e6,
                                  AV_OPT_SEARCH_CHILDREN);
      }
      if (ret >= 0 && of->start_time) {
          ret = av_opt_set_double(ctx, "start", (double)of->start_time / 1e6,
                                  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 configure_output_video_filter(FilterGraph *fg, OutputFilter *ofilter, AVFilterInOut *out)
  {
      char *pix_fmts;
      OutputStream *ost = ofilter->ost;
      AVCodecContext *codec = ost->st->codec;
      AVFilterContext *last_filter = out->filter_ctx;
      int pad_idx = out->pad_idx;
      int ret;
      char name[255];
  
      snprintf(name, sizeof(name), "output stream %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 (codec->width || codec->height) {
          char args[255];
          AVFilterContext *filter;
  
          snprintf(args, sizeof(args), "%d:%d:0x%X",
                   codec->width,
                   codec->height,
                   (unsigned)ost->sws_flags);
          snprintf(name, sizeof(name), "scaler for output stream %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(ost))) {
          AVFilterContext *filter;
          snprintf(name, sizeof(name), "pixel format for output stream %d:%d",
                   ost->file_index, ost->index);
          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 for output stream %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;
      }
  
      ret = insert_trim(ost, &last_filter, &pad_idx);
      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;
      AVCodecContext *codec  = ost->st->codec;
      AVFilterContext *last_filter = out->filter_ctx;
      OutputFile *of = output_files[ost->file_index];
      int pad_idx = out->pad_idx;
      char *sample_fmts, *sample_rates, *channel_layouts;
      char name[255];
      int ret;
  
      snprintf(name, sizeof(name), "output stream %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)                                                            \
          return ret;                                                         \
                                                                              \
      ret = avfilter_link(last_filter, pad_idx, filt_ctx, 0);                 \
      if (ret < 0)                                                            \
          return ret;                                                         \
                                                                              \
      last_filter = filt_ctx;                                                 \
      pad_idx = 0;                                                            \
  } while (0)
      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("-map_channel", "pan", pan_buf.str);
          av_bprint_finalize(&pan_buf, NULL);
      }
  
      if (codec->channels && !codec->channel_layout)
          codec->channel_layout = av_get_default_channel_layout(codec->channels);
  
      sample_fmts     = choose_sample_fmts(ost);
      sample_rates    = choose_sample_rates(ost);
      channel_layouts = choose_channel_layouts(ost);
      if (sample_fmts || sample_rates || channel_layouts) {
          AVFilterContext *format;
          char args[256];
          args[0] = 0;
  
          if (sample_fmts)
              av_strlcatf(args, sizeof(args), "sample_fmts=%s:",
                              sample_fmts);
          if (sample_rates)
              av_strlcatf(args, sizeof(args), "sample_rates=%s:",
                              sample_rates);
          if (channel_layouts)
              av_strlcatf(args, sizeof(args), "channel_layouts=%s:",
                              channel_layouts);
  
          av_freep(&sample_fmts);
          av_freep(&sample_rates);
          av_freep(&channel_layouts);
  
          snprintf(name, sizeof(name), "audio format for output stream %d:%d",
                   ost->file_index, ost->index);
          ret = avfilter_graph_create_filter(&format,
                                             avfilter_get_by_name("aformat"),
                                             name, args, NULL, fg->graph);
          if (ret < 0)
              return ret;
  
          ret = avfilter_link(last_filter, pad_idx, format, 0);
          if (ret < 0)
              return ret;
  
          last_filter = format;
          pad_idx = 0;
      }
  
      if (audio_volume != 256 && 0) {
          char args[256];
  
          snprintf(args, sizeof(args), "%f", audio_volume / 256.);
          AUTO_INSERT_FILTER("-vol", "volume", args);
      }
  
      if (ost->apad && of->shortest) {
          char args[256];
          int i;
  
          for (i=0; i<of->ctx->nb_streams; i++)
              if (of->ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
                  break;
  
          if (i<of->ctx->nb_streams) {
              snprintf(args, sizeof(args), "%s", ost->apad);
              AUTO_INSERT_FILTER("-apad", "apad", args);
          }
      }
  
      ret = insert_trim(ost, &last_filter, &pad_idx);
      if (ret < 0)
          return ret;
  
      if ((ret = avfilter_link(last_filter, pad_idx, ofilter->filter, 0)) < 0)
          return ret;
  
      return 0;
  }
  
  #define DESCRIBE_FILTER_LINK(f, inout, in)                         \
  {                                                                  \
      AVFilterContext *ctx = inout->filter_ctx;                      \
      AVFilterPad *pads = in ? ctx->input_pads  : ctx->output_pads;  \
      int       nb_pads = in ? ctx->input_count : ctx->output_count; \
      AVIOContext *pb;                                               \
                                                                     \
      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, &f->name);                              \
  }
  
  int configure_output_filter(FilterGraph *fg, OutputFilter *ofilter, AVFilterInOut *out)
  {
      av_freep(&ofilter->name);
      DESCRIBE_FILTER_LINK(ofilter, out, 0);
  
      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);
      }
  }
  
  static int sub2video_prepare(InputStream *ist)
  {
      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 codec has set a size, use it. Otherwise use the
         maximum dimensions of the video streams in the same file. */
      w = ist->st->codec->width;
      h = ist->st->codec->height;
      if (!(w && h)) {
          for (i = 0; i < avf->nb_streams; i++) {
              if (avf->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
                  w = FFMAX(w, avf->streams[i]->codec->width);
                  h = FFMAX(h, avf->streams[i]->codec->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 = ist->st->codec->width  = ist->resample_width  = w;
      ist->sub2video.h = ist->st->codec->height = ist->resample_height = h;
  
      /* rectangles are AV_PIX_FMT_PAL8, but we have no guarantee that the
         palettes for all rectangles are identical or compatible */
      ist->resample_pix_fmt = ist->st->codec->pix_fmt = AV_PIX_FMT_RGB32;
  
      ist->sub2video.frame = av_frame_alloc();
      if (!ist->sub2video.frame)
          return AVERROR(ENOMEM);
      return 0;
  }
  
  static int configure_input_video_filter(FilterGraph *fg, InputFilter *ifilter,
                                          AVFilterInOut *in)
  {
      AVFilterContext *first_filter = in->filter_ctx;
      AVFilter *filter = avfilter_get_by_name("buffer");
      InputStream *ist = ifilter->ist;
      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 pad_idx = in->pad_idx;
      int ret;
  
      if (!fr.num)
          fr = av_guess_frame_rate(input_files[ist->file_index]->ctx, ist->st, NULL);
  
      if (ist->st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
          ret = sub2video_prepare(ist);
          if (ret < 0)
              return ret;
      }
  
      sar = ist->st->sample_aspect_ratio.num ?
            ist->st->sample_aspect_ratio :
            ist->st->codec->sample_aspect_ratio;
      if(!sar.den)
          sar = (AVRational){0,1};
      av_bprint_init(&args, 0, 1);
      av_bprintf(&args,
               "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:"
               "pixel_aspect=%d/%d:sws_param=flags=%d", ist->resample_width,
               ist->resample_height, ist->resample_pix_fmt,
               tb.num, tb.den, sar.num, sar.den,
               SWS_BILINEAR + ((ist->st->codec->flags&CODEC_FLAG_BITEXACT) ? SWS_BITEXACT:0));
      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, filter, name,
                                              args.str, NULL, fg->graph)) < 0)
          return ret;
  
      if (ist->framerate.num) {
          AVFilterContext *setpts;
  
          snprintf(name, sizeof(name), "force CFR for input from stream %d:%d",
                   ist->file_index, ist->st->index);
          if ((ret = avfilter_graph_create_filter(&setpts,
                                                  avfilter_get_by_name("setpts"),
                                                  name, "N", NULL,
                                                  fg->graph)) < 0)
              return ret;
  
          if ((ret = avfilter_link(setpts, 0, first_filter, pad_idx)) < 0)
              return ret;
  
          first_filter = setpts;
          pad_idx = 0;
      }
  
      if (do_deinterlace) {
          AVFilterContext *yadif;
  
          snprintf(name, sizeof(name), "deinterlace input from stream %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(yadif, 0, first_filter, pad_idx)) < 0)
              return ret;
  
          first_filter = yadif;
          pad_idx = 0;
      }
  
      if ((ret = avfilter_link(ifilter->filter, 0, first_filter, pad_idx)) < 0)
          return ret;
      return 0;
  }
  
  static int configure_input_audio_filter(FilterGraph *fg, InputFilter *ifilter,
                                          AVFilterInOut *in)
  {
      AVFilterContext *first_filter = in->filter_ctx;
      AVFilter *filter = avfilter_get_by_name("abuffer");
      InputStream *ist = ifilter->ist;
      int pad_idx = in->pad_idx;
      AVBPrint args;
      char name[255];
      int ret;
  
      av_bprint_init(&args, 0, AV_BPRINT_SIZE_AUTOMATIC);
      av_bprintf(&args, "time_base=%d/%d:sample_rate=%d:sample_fmt=%s",
               1, ist->st->codec->sample_rate,
               ist->st->codec->sample_rate,
               av_get_sample_fmt_name(ist->st->codec->sample_fmt));
      if (ist->st->codec->channel_layout)
          av_bprintf(&args, ":channel_layout=0x%"PRIx64,
                     ist->st->codec->channel_layout);
      else
          av_bprintf(&args, ":channels=%d", ist->st->codec->channels);
      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, filter,
                                              name, args.str, NULL,
                                              fg->graph)) < 0)
          return ret;
  
  #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 for input stream %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(filt_ctx, 0, first_filter, pad_idx);                \
      if (ret < 0)                                                            \
          return ret;                                                         \
                                                                              \
      first_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);
      }
      if ((ret = avfilter_link(ifilter->filter, 0, first_filter, pad_idx)) < 0)
          return ret;
  
      return 0;
  }
  
  static int configure_input_filter(FilterGraph *fg, InputFilter *ifilter,
                                    AVFilterInOut *in)
  {
      av_freep(&ifilter->name);
      DESCRIBE_FILTER_LINK(ifilter, in, 1);
  
      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);
      }
  }
  
  int configure_filtergraph(FilterGraph *fg)
  {
      AVFilterInOut *inputs, *outputs, *cur;
      int ret, i, init = !fg->graph, simple = !fg->graph_desc;
      const char *graph_desc = simple ? fg->outputs[0]->ost->avfilter :
                                        fg->graph_desc;
  
      avfilter_graph_free(&fg->graph);
      if (!(fg->graph = avfilter_graph_alloc()))
          return AVERROR(ENOMEM);
  
      if (simple) {
          OutputStream *ost = fg->outputs[0]->ost;
          char args[512];
          AVDictionaryEntry *e = NULL;
  
          snprintf(args, sizeof(args), "flags=0x%X", (unsigned)ost->sws_flags);
          fg->graph->scale_sws_opts = av_strdup(args);
  
          args[0] = 0;
          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);
  
          args[0] = '\0';
          while ((e = av_dict_get(fg->outputs[0]->ost->resample_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';
          fg->graph->resample_lavr_opts = av_strdup(args);
      }
  
      if ((ret = avfilter_graph_parse2(fg->graph, graph_desc, &inputs, &outputs)) < 0)
          return ret;
  
      if (simple && (!inputs || inputs->next || !outputs || outputs->next)) {
          av_log(NULL, AV_LOG_ERROR, "Simple filtergraph '%s' does not have "
                 "exactly one input and output.\n", graph_desc);
          return AVERROR(EINVAL);
      }
  
      for (cur = inputs; !simple && init && cur; cur = cur->next)
          init_input_filter(fg, cur);
  
      for (cur = inputs, i = 0; cur; cur = cur->next, i++)
          if ((ret = configure_input_filter(fg, fg->inputs[i], cur)) < 0)
              return ret;
      avfilter_inout_free(&inputs);
  
      if (!init || simple) {
          /* we already know the mappings between lavfi outputs and output streams,
           * so we can finish the setup */
          for (cur = outputs, i = 0; cur; cur = cur->next, i++)
              configure_output_filter(fg, fg->outputs[i], cur);
          avfilter_inout_free(&outputs);
  
          if ((ret = avfilter_graph_config(fg->graph, NULL)) < 0)
              return ret;
      } else {
          /* wait until output mappings are processed */
          for (cur = outputs; cur;) {
              GROW_ARRAY(fg->outputs, fg->nb_outputs);
              if (!(fg->outputs[fg->nb_outputs - 1] = av_mallocz(sizeof(*fg->outputs[0]))))
                  exit_program(1);
              fg->outputs[fg->nb_outputs - 1]->graph   = fg;
              fg->outputs[fg->nb_outputs - 1]->out_tmp = cur;
              cur = cur->next;
              fg->outputs[fg->nb_outputs - 1]->out_tmp->next = NULL;
          }
      }
  
      fg->reconfiguration = 1;
      return 0;
  }
  
  int ist_in_filtergraph(FilterGraph *fg, InputStream *ist)
  {
      int i;
      for (i = 0; i < fg->nb_inputs; i++)
          if (fg->inputs[i]->ist == ist)
              return 1;
      return 0;
  }
  
  