/*
  * 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/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;
     AVFilterGraph *graph;
     AVFilterContext **sinks;
     int *sink_stream_map;
     int *stream_sink_map;
 } LavfiContext;
 
 static int *create_all_formats(int n)
 {
     int i, j, *fmts, count = 0;
 
     for (i = 0; i < n; i++)
         if (!(av_pix_fmt_descriptors[i].flags & PIX_FMT_HWACCEL))
             count++;
 
     if (!(fmts = av_malloc((count+1) * sizeof(int))))
         return NULL;
     for (j = 0, i = 0; i < n; i++) {
         if (!(av_pix_fmt_descriptors[i].flags & PIX_FMT_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->stream_sink_map);
     avfilter_graph_free(&lavfi->graph);
 
     return 0;
 }
 
 av_cold static int lavfi_read_header(AVFormatContext *avctx,
                                      AVFormatParameters *ap)
 {
     LavfiContext *lavfi = avctx->priv_data;
     AVFilterInOut *input_links = NULL, *output_links = NULL, *inout;

     AVFilter *buffersink, *abuffersink;

     int *pix_fmts = create_all_formats(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_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(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->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 a 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 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(sizeof(AVFilterContext *) * avctx->nb_streams);
     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) {

         AVBufferSinkParams *buffersink_params = av_buffersink_params_alloc();

         buffersink_params->pixel_fmts = pix_fmts;
 

 #if FF_API_OLD_VSINK_API
         ret = avfilter_graph_create_filter(&sink, buffersink,
                                            inout->name, NULL,
                                            pix_fmts, lavfi->graph);
 #else
         buffersink_params->pixel_fmts = pix_fmts;
         ret = avfilter_graph_create_filter(&sink, buffersink,
                                            inout->name, NULL,
                                            buffersink_params, lavfi->graph);
 #endif
         av_freep(&buffersink_params);

         if (ret < 0)
             goto end;

         } else if (type == AVMEDIA_TYPE_AUDIO) {
             enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16, -1 };
             const int packing_fmts[] = { AVFILTER_PACKED, -1 };
             const int64_t *chlayouts = avfilter_all_channel_layouts;
             AVABufferSinkParams *abuffersink_params = av_abuffersink_params_alloc();
             abuffersink_params->sample_fmts = sample_fmts;
             abuffersink_params->packing_fmts = packing_fmts;
             abuffersink_params->channel_layouts = chlayouts;
 
             ret = avfilter_graph_create_filter(&sink, abuffersink,
                                                inout->name, NULL,
                                                abuffersink_params, lavfi->graph);
             av_free(abuffersink_params);
             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);
 
     /* 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   = 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;

         } else if (link->type == AVMEDIA_TYPE_AUDIO) {
             st->codec->codec_id    = CODEC_ID_PCM_S16LE;
             st->codec->channels    = av_get_channel_layout_nb_channels(link->channel_layout);
             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;

         }
     }
 
 end:
     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;
     AVFilterBufferRef *ref;

     AVPicture pict;
     int ret, i, size;
 
     /* 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 = av_buffersink_get_buffer_ref(lavfi->sinks[i],

                                                &ref, AV_BUFFERSINK_FLAG_PEEK);

         if (ret < 0)
             return ret;

         d = av_rescale_q(ref->pts, tb, AV_TIME_BASE_Q);

         av_dlog(avctx, "sink_idx:%d time:%f\n", i, d);
 

         if (d < min_pts) {
             min_pts = d;
             min_pts_sink_idx = i;
         }
     }

     av_dlog(avctx, "min_pts_sink_idx:%i\n", min_pts_sink_idx);

     av_buffersink_get_buffer_ref(lavfi->sinks[min_pts_sink_idx], &ref, 0);
     stream_idx = lavfi->sink_stream_map[min_pts_sink_idx];

     if (ref->video) {

         size = avpicture_get_size(ref->format, ref->video->w, ref->video->h);
         if ((ret = av_new_packet(pkt, size)) < 0)
             return ret;

         memcpy(pict.data,     ref->data,     4*sizeof(ref->data[0]));
         memcpy(pict.linesize, ref->linesize, 4*sizeof(ref->linesize[0]));

         avpicture_layout(&pict, ref->format, ref->video->w,
                          ref->video->h, pkt->data, size);

     } else if (ref->audio) {

         size = ref->audio->nb_samples *
             av_get_bytes_per_sample(ref->format) *
             av_get_channel_layout_nb_channels(ref->audio->channel_layout);

         if ((ret = av_new_packet(pkt, size)) < 0)
             return ret;
         memcpy(pkt->data, ref->data[0], size);
     }

     pkt->stream_index = stream_idx;
     pkt->pts = ref->pts;
     pkt->pos = ref->pos;

     pkt->size = size;

     avfilter_unref_buffer(ref);

 
     return size;
 }
 
 #define OFFSET(x) offsetof(LavfiContext, x)
 
 #define DEC AV_OPT_FLAG_DECODING_PARAM
 
 static const AVOption options[] = {

     { "graph", "Libavfilter graph", OFFSET(graph_str),  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,
 };
 
 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,
 };