/*
  * 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(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) {

             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,
 };
 
 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,
 };