/*************  
 Paolo Medici 2010 (fixes swscale and avcodec_video2, Audio removed)
 
 BASED ON
   http://www.dranger.com/ffmpeg/tutorial03.c:
   
// tutorial03.c
// A pedagogical video player that will stream through every video frame as fast as it can
// and play audio (out of sync).
//
// Code based on FFplay, Copyright (c) 2003 Fabrice Bellard, 
// and a tutorial by Martin Bohme (boehme@inb.uni-luebeckREMOVETHIS.de)
// Tested on Gentoo, CVS version 5/01/07 compiled with GCC 4.1.1
// Use
//
// gcc -o tutorial03 tutorial03.c -lavformat -lavcodec -lz -lm `sdl-config --cflags --libs`
// to build (assuming libavformat and libavcodec are correctly installed, 
// and assuming you have sdl-config. Please refer to SDL docs for your installation.)
//
// Run using
// tutorial03 myvideofile.mpg
//
// to play the stream on your screen.


 *******************/


extern "C" {
#include <ffmpeg/libavcodec/avcodec.h>
#include <ffmpeg/libavformat/avformat.h>
#include <ffmpeg/libswscale/swscale.h>
}

#include <iostream>
#include <SDL/SDL.h>
#include <SDL/SDL_thread.h>

#ifdef __MINGW32__
#undef main /* Prevents SDL from overriding main() */
#endif

#include <stdio.h>

typedef struct PacketQueue {
  AVPacketList *first_pkt, *last_pkt;
  int nb_packets;
  int size;
  SDL_mutex *mutex;
  SDL_cond *cond;
} PacketQueue;

PacketQueue audioq;

int quit = 0;

void packet_queue_init(PacketQueue *q) {
  memset(q, 0, sizeof(PacketQueue));
  q->mutex = SDL_CreateMutex();
  q->cond = SDL_CreateCond();
}
int packet_queue_put(PacketQueue *q, AVPacket *pkt) {

  AVPacketList *pkt1;
  if(av_dup_packet(pkt) < 0) {
    return -1;
  }
  pkt1 = (AVPacketList *) av_malloc(sizeof(AVPacketList));
  if (!pkt1)
    return -1;
  pkt1->pkt = *pkt;
  pkt1->next = NULL;
  
  
  SDL_LockMutex(q->mutex);
  
  if (!q->last_pkt)
    q->first_pkt = pkt1;
  else
    q->last_pkt->next = pkt1;
  q->last_pkt = pkt1;
  q->nb_packets++;
  q->size += pkt1->pkt.size;
  SDL_CondSignal(q->cond);
  
  SDL_UnlockMutex(q->mutex);
  return 0;
}
static int packet_queue_get(PacketQueue *q, AVPacket *pkt, int block)
{
  AVPacketList *pkt1;
  int ret;
  
  SDL_LockMutex(q->mutex);
  
  for(;;) {
    
    if(quit) {
      ret = -1;
      break;
    }

    pkt1 = q->first_pkt;
    if (pkt1) {
      q->first_pkt = pkt1->next;
      if (!q->first_pkt)
	q->last_pkt = NULL;
      q->nb_packets--;
      q->size -= pkt1->pkt.size;
      *pkt = pkt1->pkt;
      av_free(pkt1);
      ret = 1;
      break;
    } else if (!block) {
      ret = 0;
      break;
    } else {
      SDL_CondWait(q->cond, q->mutex);
    }
  }
  SDL_UnlockMutex(q->mutex);
  return ret;
}

int main(int argc, char *argv[]) {
  AVFormatContext *pFormatCtx;
  int             i, videoStream;
  AVCodecContext  *pCodecCtx;
  AVCodec         *pCodec;
  AVFrame         *pFrame; 
  AVPacket        packet;
  int             frameFinished;
  float           aspect_ratio;
  
  AVCodecContext  *aCodecCtx;
  AVCodec         *aCodec;

  SDL_Overlay     *bmp;
  SDL_Surface     *screen;
  SDL_Rect        rect;
  SDL_Event       event;

  if(argc < 2) {
    fprintf(stderr, "Usage: test <file>\n");
    exit(1);
  }
  // Register all formats and codecs
  av_register_all();
  
  if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
    std::cout << "Could not initialize SDL - " << SDL_GetError() << std::endl;
    exit(1);
  }

  // Open video file
  if(av_open_input_file(&pFormatCtx, argv[1], NULL, 0, NULL)!=0)
    {
    std::cout << "Couldn't open file " << argv[1] << std::endl;
    return -1; 
    }
  
  // Retrieve stream information
  if(av_find_stream_info(pFormatCtx)<0)
    {
    std::cout << "Couldn't find stream information " << std::endl;
    return -1;
    }
  
  // Dump information about file onto standard error
  dump_format(pFormatCtx, 0, argv[1], 0);
  
  // Find the first video stream
  videoStream=-1;
  for(i=0; i<pFormatCtx->nb_streams; i++) {
    if(pFormatCtx->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO &&
       videoStream < 0) {
      videoStream=i;
    }
  }
  if(videoStream==-1)
     {
     std::cout << "Didn't find a video stream" << std::endl;
     return -1; // 
     }
  
  // audio_st = pFormatCtx->streams[index]

  // Get a pointer to the codec context for the video stream
  pCodecCtx=pFormatCtx->streams[videoStream]->codec;
  
  // Find the decoder for the video stream
  pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
  if(pCodec==NULL) {
    std::cout << "Unsupported codec!" << std::endl;
    return -1; // Codec not found
  }
  // Open codec
  if(avcodec_open(pCodecCtx, pCodec)<0)
    return -1; // Could not open codec
  
  // Allocate video frame
  pFrame=avcodec_alloc_frame();

  // Make a screen to put our video

#ifndef __DARWIN__
        screen = SDL_SetVideoMode(pCodecCtx->width, pCodecCtx->height, 0, 0);
#else
        screen = SDL_SetVideoMode(pCodecCtx->width, pCodecCtx->height, 24, 0);
#endif
  if(!screen) {
    std::cout << "SDL: could not set video mode - exiting" << std::endl;
    exit(1);
  }
  
  // Allocate a place to put our YUV image on that screen
  bmp = SDL_CreateYUVOverlay(pCodecCtx->width,
				 pCodecCtx->height,
				 SDL_YV12_OVERLAY,
				 screen);


  // Read frames and save first five frames to disk
  i=0;
  while(av_read_frame(pFormatCtx, &packet)>=0) {
    // Is this a packet from the video stream?
    if(packet.stream_index==videoStream) {
      // Decode video frame
/*
      avcodec_decode_video(pCodecCtx, pFrame, &frameFinished, 
			   packet.data, packet.size);
  */

/*
int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
                         int *got_picture_ptr,
                         AVPacket *avpkt);
*/

      avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, 
			   &packet);
    
      // Did we get a video frame?
      if(frameFinished) {
	SDL_LockYUVOverlay(bmp);

	AVPicture pict;
	pict.data[0] = bmp->pixels[0];
	pict.data[1] = bmp->pixels[2];
	pict.data[2] = bmp->pixels[1];

	pict.linesize[0] = bmp->pitches[0];
	pict.linesize[1] = bmp->pitches[2];
	pict.linesize[2] = bmp->pitches[1];

        SwsContext * convert_ctx = sws_getContext ( pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt,
                                   pCodecCtx->width, pCodecCtx->height,  PIX_FMT_YUV420P,
                                   SWS_BICUBIC, NULL, NULL, NULL );
                                   
	sws_scale( convert_ctx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pict.data, pict.linesize );

        sws_freeContext ( convert_ctx );


/*
	// Convert the image into YUV format that SDL uses
	img_convert(&pict, PIX_FMT_YUV420P,
                    (AVPicture *)pFrame, pCodecCtx->pix_fmt, 
		    pCodecCtx->width, pCodecCtx->height);
*/	
	SDL_UnlockYUVOverlay(bmp);
	
	rect.x = 0;
	rect.y = 0;
	rect.w = pCodecCtx->width;
	rect.h = pCodecCtx->height;
	SDL_DisplayYUVOverlay(bmp, &rect);
	av_free_packet(&packet);
      }
    } else {
      av_free_packet(&packet);
    }
    // Free the packet that was allocated by av_read_frame
    SDL_PollEvent(&event);
    switch(event.type) {
    case SDL_QUIT:
      quit = 1;
      SDL_Quit();
      exit(0);
      break;
    default:
      break;
    }

  }

  // Free the YUV frame
  av_free(pFrame);
  
  // Close the codec
  avcodec_close(pCodecCtx);
  
  // Close the video file
  av_close_input_file(pFormatCtx);
  
  return 0;
}