/*
  * Copyright (c) 2010 Stefano Sabatini
  * Copyright (c) 2008 Victor Paesa
  *
  * 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
  * movie video source
  *
  * @todo use direct rendering (no allocation of a new frame)
  * @todo support a PTS correction mechanism
  * @todo support more than one output stream
  */
 
 /* #define DEBUG */
 
 #include <float.h>
 #include "libavutil/avstring.h"
 #include "libavutil/opt.h"

 #include "libavutil/imgutils.h"

 #include "libavformat/avformat.h"

 #include "avcodec.h"

 #include "avfilter.h"
 
 typedef struct {
     const AVClass *class;
     int64_t seek_point;   ///< seekpoint in microseconds
     double seek_point_d;
     char *format_name;
     char *file_name;
     int stream_index;
 
     AVFormatContext *format_ctx;
     AVCodecContext *codec_ctx;
     int is_done;
     AVFrame *frame;   ///< video frame to store the decoded images in
 
     int w, h;
     AVFilterBufferRef *picref;
 } MovieContext;
 
 #define OFFSET(x) offsetof(MovieContext, x)
 
 static const AVOption movie_options[]= {

 {"format_name",  "set format name",         OFFSET(format_name),  FF_OPT_TYPE_STRING, {.str =  0},  CHAR_MIN, CHAR_MAX },
 {"f",            "set format name",         OFFSET(format_name),  FF_OPT_TYPE_STRING, {.str =  0},  CHAR_MIN, CHAR_MAX },

 {"stream_index", "set stream index",        OFFSET(stream_index), FF_OPT_TYPE_INT,    {.dbl = -1},  -1,       INT_MAX  },
 {"si",           "set stream index",        OFFSET(stream_index), FF_OPT_TYPE_INT,    {.dbl = -1},  -1,       INT_MAX  },

 {"seek_point",   "set seekpoint (seconds)", OFFSET(seek_point_d), FF_OPT_TYPE_DOUBLE, {.dbl =  0},  0,        (INT64_MAX-1) / 1000000 },
 {"sp",           "set seekpoint (seconds)", OFFSET(seek_point_d), FF_OPT_TYPE_DOUBLE, {.dbl =  0},  0,        (INT64_MAX-1) / 1000000 },

 {NULL},
 };
 
 static const char *movie_get_name(void *ctx)
 {
     return "movie";
 }
 
 static const AVClass movie_class = {
     "MovieContext",
     movie_get_name,
     movie_options
 };
 
 static int movie_init(AVFilterContext *ctx)
 {
     MovieContext *movie = ctx->priv;
     AVInputFormat *iformat = NULL;
     AVCodec *codec;
     int ret;
     int64_t timestamp;
 
     av_register_all();
 
     // Try to find the movie format (container)
     iformat = movie->format_name ? av_find_input_format(movie->format_name) : NULL;
 
     movie->format_ctx = NULL;

     if ((ret = avformat_open_input(&movie->format_ctx, movie->file_name, iformat, NULL)) < 0) {

         av_log(ctx, AV_LOG_ERROR,

                "Failed to avformat_open_input '%s'\n", movie->file_name);

         return ret;
     }
     if ((ret = av_find_stream_info(movie->format_ctx)) < 0)
         av_log(ctx, AV_LOG_WARNING, "Failed to find stream info\n");
 
     // if seeking requested, we execute it
     if (movie->seek_point > 0) {
         timestamp = movie->seek_point;
         // add the stream start time, should it exist
         if (movie->format_ctx->start_time != AV_NOPTS_VALUE) {
             if (timestamp > INT64_MAX - movie->format_ctx->start_time) {
                 av_log(ctx, AV_LOG_ERROR,
                        "%s: seek value overflow with start_time:%"PRId64" seek_point:%"PRId64"\n",
                        movie->file_name, movie->format_ctx->start_time, movie->seek_point);
                 return AVERROR(EINVAL);
             }
             timestamp += movie->format_ctx->start_time;
         }
         if ((ret = av_seek_frame(movie->format_ctx, -1, timestamp, AVSEEK_FLAG_BACKWARD)) < 0) {
             av_log(ctx, AV_LOG_ERROR, "%s: could not seek to position %"PRId64"\n",
                    movie->file_name, timestamp);
             return ret;
         }
     }
 
     /* select the video stream */
     if ((ret = av_find_best_stream(movie->format_ctx, AVMEDIA_TYPE_VIDEO,
                                    movie->stream_index, -1, NULL, 0)) < 0) {
         av_log(ctx, AV_LOG_ERROR, "No video stream with index '%d' found\n",
                movie->stream_index);
         return ret;
     }
     movie->stream_index = ret;
     movie->codec_ctx = movie->format_ctx->streams[movie->stream_index]->codec;
 
     /*
      * So now we've got a pointer to the so-called codec context for our video
      * stream, but we still have to find the actual codec and open it.
      */
     codec = avcodec_find_decoder(movie->codec_ctx->codec_id);
     if (!codec) {
         av_log(ctx, AV_LOG_ERROR, "Failed to find any codec\n");
         return AVERROR(EINVAL);
     }
 
     if ((ret = avcodec_open(movie->codec_ctx, codec)) < 0) {
         av_log(ctx, AV_LOG_ERROR, "Failed to open codec\n");
         return ret;
     }
 
     if (!(movie->frame = avcodec_alloc_frame()) ) {
         av_log(ctx, AV_LOG_ERROR, "Failed to alloc frame\n");
         return AVERROR(ENOMEM);
     }
 
     movie->w = movie->codec_ctx->width;
     movie->h = movie->codec_ctx->height;
 

     av_log(ctx, AV_LOG_INFO, "seek_point:%"PRIi64" format_name:%s file_name:%s stream_index:%d\n",

            movie->seek_point, movie->format_name, movie->file_name,
            movie->stream_index);
 
     return 0;
 }
 
 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     MovieContext *movie = ctx->priv;
     int ret;
     movie->class = &movie_class;
     av_opt_set_defaults2(movie, 0, 0);
 
     if (args)
         movie->file_name = av_get_token(&args, ":");
     if (!movie->file_name || !*movie->file_name) {
         av_log(ctx, AV_LOG_ERROR, "No filename provided!\n");
         return AVERROR(EINVAL);
     }
 
     if (*args++ == ':' && (ret = av_set_options_string(movie, args, "=", ":")) < 0) {
         av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
         return ret;
     }
 
     movie->seek_point = movie->seek_point_d * 1000000 + 0.5;
 
     return movie_init(ctx);
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     MovieContext *movie = ctx->priv;
 
     av_free(movie->file_name);
     av_free(movie->format_name);
     if (movie->codec_ctx)
         avcodec_close(movie->codec_ctx);
     if (movie->format_ctx)
         av_close_input_file(movie->format_ctx);
     avfilter_unref_buffer(movie->picref);
     av_freep(&movie->frame);
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     MovieContext *movie = ctx->priv;
     enum PixelFormat pix_fmts[] = { movie->codec_ctx->pix_fmt, PIX_FMT_NONE };
 

     avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));

     return 0;
 }
 
 static int config_output_props(AVFilterLink *outlink)
 {
     MovieContext *movie = outlink->src->priv;
 
     outlink->w = movie->w;
     outlink->h = movie->h;
     outlink->time_base = movie->format_ctx->streams[movie->stream_index]->time_base;
 
     return 0;
 }
 
 static int movie_get_frame(AVFilterLink *outlink)
 {
     MovieContext *movie = outlink->src->priv;
     AVPacket pkt;
     int ret, frame_decoded;
     AVStream *st = movie->format_ctx->streams[movie->stream_index];
 
     if (movie->is_done == 1)
         return 0;
 
     while ((ret = av_read_frame(movie->format_ctx, &pkt)) >= 0) {
         // Is this a packet from the video stream?
         if (pkt.stream_index == movie->stream_index) {
             avcodec_decode_video2(movie->codec_ctx, movie->frame, &frame_decoded, &pkt);
 
             if (frame_decoded) {
                 /* FIXME: avoid the memcpy */
                 movie->picref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE | AV_PERM_PRESERVE |
                                                           AV_PERM_REUSE2, outlink->w, outlink->h);
                 av_image_copy(movie->picref->data, movie->picref->linesize,
                               movie->frame->data,  movie->frame->linesize,
                               movie->picref->format, outlink->w, outlink->h);

                 avfilter_copy_frame_props(movie->picref, movie->frame);

 
                 /* FIXME: use a PTS correction mechanism as that in
                  * ffplay.c when some API will be available for that */
                 /* use pkt_dts if pkt_pts is not available */
                 movie->picref->pts = movie->frame->pkt_pts == AV_NOPTS_VALUE ?
                     movie->frame->pkt_dts : movie->frame->pkt_pts;

                 if (!movie->frame->sample_aspect_ratio.num)

                     movie->picref->video->sample_aspect_ratio = st->sample_aspect_ratio;

                 av_dlog(outlink->src,
                         "movie_get_frame(): file:'%s' pts:%"PRId64" time:%lf pos:%"PRId64" aspect:%d/%d\n",
                         movie->file_name, movie->picref->pts,
                         (double)movie->picref->pts * av_q2d(st->time_base),
                         movie->picref->pos,

                         movie->picref->video->sample_aspect_ratio.num,
                         movie->picref->video->sample_aspect_ratio.den);

                 // We got it. Free the packet since we are returning
                 av_free_packet(&pkt);
 
                 return 0;
             }
         }
         // Free the packet that was allocated by av_read_frame
         av_free_packet(&pkt);
     }
 
     // On multi-frame source we should stop the mixing process when
     // the movie source does not have more frames
     if (ret == AVERROR_EOF)
         movie->is_done = 1;
     return ret;
 }
 
 static int request_frame(AVFilterLink *outlink)
 {
     AVFilterBufferRef *outpicref;
     MovieContext *movie = outlink->src->priv;
     int ret;
 
     if (movie->is_done)
         return AVERROR_EOF;
     if ((ret = movie_get_frame(outlink)) < 0)
         return ret;
 
     outpicref = avfilter_ref_buffer(movie->picref, ~0);
     avfilter_start_frame(outlink, outpicref);
     avfilter_draw_slice(outlink, 0, outlink->h, 1);
     avfilter_end_frame(outlink);

     avfilter_unref_buffer(movie->picref);
     movie->picref = NULL;

 
     return 0;
 }
 
 AVFilter avfilter_vsrc_movie = {
     .name          = "movie",
     .description   = NULL_IF_CONFIG_SMALL("Read from a movie source."),
     .priv_size     = sizeof(MovieContext),
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
 
     .inputs    = (AVFilterPad[]) {{ .name = NULL }},
     .outputs   = (AVFilterPad[]) {{ .name            = "default",
                                     .type            = AVMEDIA_TYPE_VIDEO,
                                     .request_frame   = request_frame,
                                     .config_props    = config_output_props, },
                                   { .name = NULL}},
 };