/*

  * Copyright 2012 Stefano Sabatini <stefasab gmail com>
  *

  * 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 "libavutil/imgutils.h"
 #include "lavfutils.h"
 
 int ff_load_image(uint8_t *data[4], int linesize[4],

                   int *w, int *h, enum AVPixelFormat *pix_fmt,

                   const char *filename, void *log_ctx)
 {
     AVInputFormat *iformat = NULL;

     AVFormatContext *format_ctx = NULL;

     AVCodec *codec;
     AVCodecContext *codec_ctx;

     AVCodecParameters *par;

     AVFrame *frame;
     int frame_decoded, ret = 0;
     AVPacket pkt;

     AVDictionary *opt=NULL;

     av_init_packet(&pkt);
 

     av_register_all();
 

     iformat = av_find_input_format("image2pipe");

     if ((ret = avformat_open_input(&format_ctx, filename, iformat, NULL)) < 0) {
         av_log(log_ctx, AV_LOG_ERROR,
                "Failed to open input file '%s'\n", filename);
         return ret;
     }
 

     if ((ret = avformat_find_stream_info(format_ctx, NULL)) < 0) {
         av_log(log_ctx, AV_LOG_ERROR, "Find stream info failed\n");
         return ret;
     }
 

     par = format_ctx->streams[0]->codecpar;
     codec = avcodec_find_decoder(par->codec_id);

     if (!codec) {
         av_log(log_ctx, AV_LOG_ERROR, "Failed to find codec\n");
         ret = AVERROR(EINVAL);
         goto end;
     }
 

     codec_ctx = avcodec_alloc_context3(codec);
     if (!codec_ctx) {
         av_log(log_ctx, AV_LOG_ERROR, "Failed to alloc video decoder context\n");
         ret = AVERROR(ENOMEM);
         goto end;
     }
 
     ret = avcodec_parameters_to_context(codec_ctx, par);
     if (ret < 0) {
         av_log(log_ctx, AV_LOG_ERROR, "Failed to copy codec parameters to decoder context\n");
         goto end;
     }
 

     av_dict_set(&opt, "thread_type", "slice", 0);
     if ((ret = avcodec_open2(codec_ctx, codec, &opt)) < 0) {

         av_log(log_ctx, AV_LOG_ERROR, "Failed to open codec\n");
         goto end;
     }
 

     if (!(frame = av_frame_alloc()) ) {

         av_log(log_ctx, AV_LOG_ERROR, "Failed to alloc frame\n");
         ret = AVERROR(ENOMEM);
         goto end;
     }
 
     ret = av_read_frame(format_ctx, &pkt);
     if (ret < 0) {
         av_log(log_ctx, AV_LOG_ERROR, "Failed to read frame from file\n");
         goto end;
     }
 
     ret = avcodec_decode_video2(codec_ctx, frame, &frame_decoded, &pkt);
     if (ret < 0 || !frame_decoded) {
         av_log(log_ctx, AV_LOG_ERROR, "Failed to decode image from file\n");

         if (ret >= 0)
             ret = -1;

         goto end;
     }
 
     *w       = frame->width;
     *h       = frame->height;
     *pix_fmt = frame->format;
 
     if ((ret = av_image_alloc(data, linesize, *w, *h, *pix_fmt, 16)) < 0)
         goto end;
     ret = 0;
 

     av_image_copy(data, linesize, (const uint8_t **)frame->data, frame->linesize, *pix_fmt, *w, *h);

 
 end:

     av_packet_unref(&pkt);

     avcodec_free_context(&codec_ctx);

     avformat_close_input(&format_ctx);

     av_frame_free(&frame);

     av_dict_free(&opt);

 
     if (ret < 0)
         av_log(log_ctx, AV_LOG_ERROR, "Error loading image file '%s'\n", filename);
     return ret;
 }