text: /*
   * Copyright (c) 2011 Stefano Sabatini
   *
   * 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
   */
  
  /**
   * @file
   * libavfilter virtual input device
   */
  
  /* #define DEBUG */
  
  #include <float.h>              /* DBL_MIN, DBL_MAX */
  
  #include "libavutil/bprint.h"
  #include "libavutil/channel_layout.h"
  #include "libavutil/file.h"
  #include "libavutil/log.h"
  #include "libavutil/mem.h"
  #include "libavutil/opt.h"
  #include "libavutil/parseutils.h"
  #include "libavutil/pixdesc.h"
  #include "libavfilter/avfilter.h"
  #include "libavfilter/avfiltergraph.h"
  #include "libavfilter/buffersink.h"
  #include "libavformat/internal.h"
  #include "avdevice.h"
  
  typedef struct {
      AVClass *class;          ///< class for private options
      char          *graph_str;
      char          *graph_filename;
      char          *dump_graph;
      AVFilterGraph *graph;
      AVFilterContext **sinks;
      int *sink_stream_map;
      int *sink_eof;
      int *stream_sink_map;
      AVFrame *decoded_frame;
  } LavfiContext;
  
  static int *create_all_formats(int n)
  {
      int i, j, *fmts, count = 0;
  
      for (i = 0; i < n; i++) {
          const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(i);
          if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL))
              count++;
      }
  
      if (!(fmts = av_malloc((count+1) * sizeof(int))))
          return NULL;
      for (j = 0, i = 0; i < n; i++) {
          const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(i);
          if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL))
              fmts[j++] = i;
      }
      fmts[j] = -1;
      return fmts;
  }
  
  av_cold static int lavfi_read_close(AVFormatContext *avctx)
  {
      LavfiContext *lavfi = avctx->priv_data;
  
      av_freep(&lavfi->sink_stream_map);
      av_freep(&lavfi->sink_eof);
      av_freep(&lavfi->stream_sink_map);
      av_freep(&lavfi->sinks);
      avfilter_graph_free(&lavfi->graph);
      av_frame_free(&lavfi->decoded_frame);
  
      return 0;
  }
  
  av_cold static int lavfi_read_header(AVFormatContext *avctx)
  {
      LavfiContext *lavfi = avctx->priv_data;
      AVFilterInOut *input_links = NULL, *output_links = NULL, *inout;
      AVFilter *buffersink, *abuffersink;
      int *pix_fmts = create_all_formats(AV_PIX_FMT_NB);
      enum AVMediaType type;
      int ret = 0, i, n;
  
  #define FAIL(ERR) { ret = ERR; goto end; }
  
      if (!pix_fmts)
          FAIL(AVERROR(ENOMEM));
  
      avfilter_register_all();
  
      buffersink = avfilter_get_by_name("buffersink");
      abuffersink = avfilter_get_by_name("abuffersink");
  
      if (lavfi->graph_filename && lavfi->graph_str) {
          av_log(avctx, AV_LOG_ERROR,
                 "Only one of the graph or graph_file options must be specified\n");
          FAIL(AVERROR(EINVAL));
      }
  
      if (lavfi->graph_filename) {
          uint8_t *file_buf, *graph_buf;
          size_t file_bufsize;
          ret = av_file_map(lavfi->graph_filename,
                            &file_buf, &file_bufsize, 0, avctx);
          if (ret < 0)
              goto end;
  
          /* create a 0-terminated string based on the read file */
          graph_buf = av_malloc(file_bufsize + 1);
          if (!graph_buf) {
              av_file_unmap(file_buf, file_bufsize);
              FAIL(AVERROR(ENOMEM));
          }
          memcpy(graph_buf, file_buf, file_bufsize);
          graph_buf[file_bufsize] = 0;
          av_file_unmap(file_buf, file_bufsize);
          lavfi->graph_str = graph_buf;
      }
  
      if (!lavfi->graph_str)
          lavfi->graph_str = av_strdup(avctx->filename);
  
      /* parse the graph, create a stream for each open output */
      if (!(lavfi->graph = avfilter_graph_alloc()))
          FAIL(AVERROR(ENOMEM));
  
      if ((ret = avfilter_graph_parse_ptr(lavfi->graph, lavfi->graph_str,
                                      &input_links, &output_links, avctx)) < 0)
          FAIL(ret);
  
      if (input_links) {
          av_log(avctx, AV_LOG_ERROR,
                 "Open inputs in the filtergraph are not acceptable\n");
          FAIL(AVERROR(EINVAL));
      }
  
      /* count the outputs */
      for (n = 0, inout = output_links; inout; n++, inout = inout->next);
  
      if (!(lavfi->sink_stream_map = av_malloc(sizeof(int) * n)))
          FAIL(AVERROR(ENOMEM));
      if (!(lavfi->sink_eof = av_mallocz(sizeof(int) * n)))
          FAIL(AVERROR(ENOMEM));
      if (!(lavfi->stream_sink_map = av_malloc(sizeof(int) * n)))
          FAIL(AVERROR(ENOMEM));
  
      for (i = 0; i < n; i++)
          lavfi->stream_sink_map[i] = -1;
  
      /* parse the output link names - they need to be of the form out0, out1, ...
       * create a mapping between them and the streams */
      for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
          int stream_idx;
          if (!strcmp(inout->name, "out"))
              stream_idx = 0;
          else if (sscanf(inout->name, "out%d\n", &stream_idx) != 1) {
              av_log(avctx,  AV_LOG_ERROR,
                     "Invalid outpad name '%s'\n", inout->name);
              FAIL(AVERROR(EINVAL));
          }
  
          if ((unsigned)stream_idx >= n) {
              av_log(avctx, AV_LOG_ERROR,
                     "Invalid index was specified in output '%s', "
                     "must be a non-negative value < %d\n",
                     inout->name, n);
              FAIL(AVERROR(EINVAL));
          }
  
          /* is an audio or video output? */
          type = inout->filter_ctx->output_pads[inout->pad_idx].type;
          if (type != AVMEDIA_TYPE_VIDEO && type != AVMEDIA_TYPE_AUDIO) {
              av_log(avctx,  AV_LOG_ERROR,
                     "Output '%s' is not a video or audio output, not yet supported\n", inout->name);
              FAIL(AVERROR(EINVAL));
          }
  
          if (lavfi->stream_sink_map[stream_idx] != -1) {
              av_log(avctx,  AV_LOG_ERROR,
                     "An output with stream index %d was already specified\n",
                     stream_idx);
              FAIL(AVERROR(EINVAL));
          }
          lavfi->sink_stream_map[i] = stream_idx;
          lavfi->stream_sink_map[stream_idx] = i;
      }
  
      /* for each open output create a corresponding stream */
      for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
          AVStream *st;
          if (!(st = avformat_new_stream(avctx, NULL)))
              FAIL(AVERROR(ENOMEM));
          st->id = i;
      }
  
      /* create a sink for each output and connect them to the graph */
      lavfi->sinks = av_malloc_array(avctx->nb_streams, sizeof(AVFilterContext *));
      if (!lavfi->sinks)
          FAIL(AVERROR(ENOMEM));
  
      for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
          AVFilterContext *sink;
  
          type = inout->filter_ctx->output_pads[inout->pad_idx].type;
  
          if (type == AVMEDIA_TYPE_VIDEO && ! buffersink ||
              type == AVMEDIA_TYPE_AUDIO && ! abuffersink) {
                  av_log(avctx, AV_LOG_ERROR, "Missing required buffersink filter, aborting.\n");
                  FAIL(AVERROR_FILTER_NOT_FOUND);
          }
  
          if (type == AVMEDIA_TYPE_VIDEO) {
              ret = avfilter_graph_create_filter(&sink, buffersink,
                                                 inout->name, NULL,
                                                 NULL, lavfi->graph);
              if (ret >= 0)
                  ret = av_opt_set_int_list(sink, "pix_fmts", pix_fmts,  AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN);
              if (ret < 0)
                  goto end;
          } else if (type == AVMEDIA_TYPE_AUDIO) {
              enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_U8,
                                                    AV_SAMPLE_FMT_S16,
                                                    AV_SAMPLE_FMT_S32,
                                                    AV_SAMPLE_FMT_FLT,
                                                    AV_SAMPLE_FMT_DBL, -1 };
  
              ret = avfilter_graph_create_filter(&sink, abuffersink,
                                                 inout->name, NULL,
                                                 NULL, lavfi->graph);
              if (ret >= 0)
                  ret = av_opt_set_int_list(sink, "sample_fmts", sample_fmts,  AV_SAMPLE_FMT_NONE, AV_OPT_SEARCH_CHILDREN);
              if (ret < 0)
                  goto end;
              ret = av_opt_set_int(sink, "all_channel_counts", 1,
                                   AV_OPT_SEARCH_CHILDREN);
              if (ret < 0)
                  goto end;
          }
  
          lavfi->sinks[i] = sink;
          if ((ret = avfilter_link(inout->filter_ctx, inout->pad_idx, sink, 0)) < 0)
              FAIL(ret);
      }
  
      /* configure the graph */
      if ((ret = avfilter_graph_config(lavfi->graph, avctx)) < 0)
          FAIL(ret);
  
      if (lavfi->dump_graph) {
          char *dump = avfilter_graph_dump(lavfi->graph, lavfi->dump_graph);
          fputs(dump, stderr);
          fflush(stderr);
          av_free(dump);
      }
  
      /* fill each stream with the information in the corresponding sink */
      for (i = 0; i < avctx->nb_streams; i++) {
          AVFilterLink *link = lavfi->sinks[lavfi->stream_sink_map[i]]->inputs[0];
          AVStream *st = avctx->streams[i];
          st->codec->codec_type = link->type;
          avpriv_set_pts_info(st, 64, link->time_base.num, link->time_base.den);
          if (link->type == AVMEDIA_TYPE_VIDEO) {
              st->codec->codec_id   = AV_CODEC_ID_RAWVIDEO;
              st->codec->pix_fmt    = link->format;
              st->codec->time_base  = link->time_base;
              st->codec->width      = link->w;
              st->codec->height     = link->h;
              st       ->sample_aspect_ratio =
              st->codec->sample_aspect_ratio = link->sample_aspect_ratio;
              avctx->probesize = FFMAX(avctx->probesize,
                                       link->w * link->h *
                                       av_get_padded_bits_per_pixel(av_pix_fmt_desc_get(link->format)) *
                                       30);
          } else if (link->type == AVMEDIA_TYPE_AUDIO) {
              st->codec->codec_id    = av_get_pcm_codec(link->format, -1);
              st->codec->channels    = avfilter_link_get_channels(link);
              st->codec->sample_fmt  = link->format;
              st->codec->sample_rate = link->sample_rate;
              st->codec->time_base   = link->time_base;
              st->codec->channel_layout = link->channel_layout;
              if (st->codec->codec_id == AV_CODEC_ID_NONE)
                  av_log(avctx, AV_LOG_ERROR,
                         "Could not find PCM codec for sample format %s.\n",
                         av_get_sample_fmt_name(link->format));
          }
      }
  
      if (!(lavfi->decoded_frame = av_frame_alloc()))
          FAIL(AVERROR(ENOMEM));
  
  end:
      av_free(pix_fmts);
      avfilter_inout_free(&input_links);
      avfilter_inout_free(&output_links);
      if (ret < 0)
          lavfi_read_close(avctx);
      return ret;
  }
  
  static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
  {
      LavfiContext *lavfi = avctx->priv_data;
      double min_pts = DBL_MAX;
      int stream_idx, min_pts_sink_idx = 0;
      AVFrame *frame = lavfi->decoded_frame;
      AVPicture pict;
      AVDictionary *frame_metadata;
      int ret, i;
      int size = 0;
  
      /* iterate through all the graph sinks. Select the sink with the
       * minimum PTS */
      for (i = 0; i < avctx->nb_streams; i++) {
          AVRational tb = lavfi->sinks[i]->inputs[0]->time_base;
          double d;
          int ret;
  
          if (lavfi->sink_eof[i])
              continue;
  
          ret = av_buffersink_get_frame_flags(lavfi->sinks[i], frame,
                                              AV_BUFFERSINK_FLAG_PEEK);
          if (ret == AVERROR_EOF) {
              av_dlog(avctx, "EOF sink_idx:%d\n", i);
              lavfi->sink_eof[i] = 1;
              continue;
          } else if (ret < 0)
              return ret;
          d = av_rescale_q(frame->pts, tb, AV_TIME_BASE_Q);
          av_dlog(avctx, "sink_idx:%d time:%f\n", i, d);
          av_frame_unref(frame);
  
          if (d < min_pts) {
              min_pts = d;
              min_pts_sink_idx = i;
          }
      }
      if (min_pts == DBL_MAX)
          return AVERROR_EOF;
  
      av_dlog(avctx, "min_pts_sink_idx:%i\n", min_pts_sink_idx);
  
      av_buffersink_get_frame_flags(lavfi->sinks[min_pts_sink_idx], frame, 0);
      stream_idx = lavfi->sink_stream_map[min_pts_sink_idx];
  
      if (frame->width /* FIXME best way of testing a video */) {
          size = avpicture_get_size(frame->format, frame->width, frame->height);
          if ((ret = av_new_packet(pkt, size)) < 0)
              return ret;
  
          memcpy(pict.data,     frame->data,     4*sizeof(frame->data[0]));
          memcpy(pict.linesize, frame->linesize, 4*sizeof(frame->linesize[0]));
  
          avpicture_layout(&pict, frame->format, frame->width, frame->height,
                           pkt->data, size);
      } else if (av_frame_get_channels(frame) /* FIXME test audio */) {
          size = frame->nb_samples * av_get_bytes_per_sample(frame->format) *
                                     av_frame_get_channels(frame);
          if ((ret = av_new_packet(pkt, size)) < 0)
              return ret;
          memcpy(pkt->data, frame->data[0], size);
      }
  
      frame_metadata = av_frame_get_metadata(frame);
      if (frame_metadata) {
          uint8_t *metadata;
          AVDictionaryEntry *e = NULL;
          AVBPrint meta_buf;
  
          av_bprint_init(&meta_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
          while ((e = av_dict_get(frame_metadata, "", e, AV_DICT_IGNORE_SUFFIX))) {
              av_bprintf(&meta_buf, "%s", e->key);
              av_bprint_chars(&meta_buf, '\0', 1);
              av_bprintf(&meta_buf, "%s", e->value);
              av_bprint_chars(&meta_buf, '\0', 1);
          }
          if (!av_bprint_is_complete(&meta_buf) ||
              !(metadata = av_packet_new_side_data(pkt, AV_PKT_DATA_STRINGS_METADATA,
                                                   meta_buf.len))) {
              av_bprint_finalize(&meta_buf, NULL);
              return AVERROR(ENOMEM);
          }
          memcpy(metadata, meta_buf.str, meta_buf.len);
          av_bprint_finalize(&meta_buf, NULL);
      }
  
      pkt->stream_index = stream_idx;
      pkt->pts = frame->pts;
      pkt->pos = av_frame_get_pkt_pos(frame);
      pkt->size = size;
      av_frame_unref(frame);
      return size;
  }
  
  #define OFFSET(x) offsetof(LavfiContext, x)
  
  #define DEC AV_OPT_FLAG_DECODING_PARAM
  
  static const AVOption options[] = {
      { "graph",     "set libavfilter graph", OFFSET(graph_str),  AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
      { "graph_file","set libavfilter graph filename", OFFSET(graph_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC},
      { "dumpgraph", "dump graph to stderr",  OFFSET(dump_graph), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
      { NULL },
  };
  
  static const AVClass lavfi_class = {
      .class_name = "lavfi indev",
      .item_name  = av_default_item_name,
      .option     = options,
      .version    = LIBAVUTIL_VERSION_INT,
      .category   = AV_CLASS_CATEGORY_DEVICE_INPUT,
  };
  
  AVInputFormat ff_lavfi_demuxer = {
      .name           = "lavfi",
      .long_name      = NULL_IF_CONFIG_SMALL("Libavfilter virtual input device"),
      .priv_data_size = sizeof(LavfiContext),
      .read_header    = lavfi_read_header,
      .read_packet    = lavfi_read_packet,
      .read_close     = lavfi_read_close,
      .flags          = AVFMT_NOFILE,
      .priv_class     = &lavfi_class,
  };
  