/*
  *  yuvrfps.c
  *  does a frame rate reduction based on simple frame drop.
  *  drops 1 frame every X
  *  This is to work with progressive 3:2 pulldown files 
  *  Or files converted to a higher frame rate via frame doubling.
  *  Similar to yuvkineco but can handle any sort of reduction
  *  The program looks at X number of frames and removes the one which is duplicated
  *
  *  modified from yuvfps.c by
  *  Copyright (C) 2002 Alfonso Garcia-Patiņo Barbolani
  *
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *  the Free Software Foundation; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  This program 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 General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>


#include "yuv4mpeg.h"
#include "mpegconsts.h"

#define YUVRFPS_VERSION "0.1"

static void print_usage() 
{
  fprintf (stderr,
	   "usage: yuvaddetect [-v -h -Ip|b|p]\n"
	   "yuvaddetect produces a 2d graph showing time vs frame difference\n"
           "\n"
	   "\t -v Verbosity degree : 0=quiet, 1=normal, 2=verbose/debug\n"
	   "\t -I<pbt> Force interlace mode\n"
	   "\t -h print this help\n"
         );
}

void copyfield(int which, int width, int height, unsigned char *input[], unsigned char *output[])
{
	// "which" is 0 for top field, 1 for bottom field
	int r = 0;
	int chromasize = width / 2;
	for (r = which; r < height; r += 2)
	{
		int chromapos = (r / 2) * (width / 2); 
		memcpy(&output[0][r * width], &input[0][r * width], width);
		memcpy(&output[1][chromapos], &input[1][chromapos], chromasize);
		memcpy(&output[2][chromapos], &input[2][chromapos], chromasize);
	}
}



// read X frames
// diff each frame (X-1)
// for 1 to X
// if frame != diff write frame 


static void detect(  int fdIn , y4m_stream_info_t  *inStrInfo,
int fdOut, y4m_stream_info_t  *outStrInfo,
int interlacing, int drop_frames)
{
  y4m_frame_info_t   in_frame ;
  uint8_t            *yuv_data[drop_frames+1][3] ;	

  int                frame_data_size ;
  int                read_error_code ;
  int                write_error_code ;
  int                src_frame_counter ;
  int *bri, *bro,l=0,f=0,mini=0,mino=0,dropmo=0,dropmi=0,x,w,h;

  // Allocate memory for the YUV channels
	w = y4m_si_get_width(inStrInfo);
	h =  y4m_si_get_height(inStrInfo);
	frame_data_size = h *w;

	bri = (int *)malloc(sizeof(int) * (drop_frames+1));
	bro = (int *)malloc(sizeof(int) * (drop_frames+1));
	// should check for allocation errors here.

	for (f=0; f<= drop_frames; f++) {
		yuv_data[f][0] = (uint8_t *)malloc( frame_data_size );
		yuv_data[f][1] = (uint8_t *)malloc( frame_data_size >> 2);
		yuv_data[f][2] = (uint8_t *)malloc( frame_data_size >> 2);
		if( !yuv_data[f][0] || !yuv_data[f][1] || !yuv_data[f][2]) 
		    mjpeg_error_exit1 ("Could'nt allocate memory for the YUV4MPEG data!");  
	}

  write_error_code = Y4M_OK ;

  src_frame_counter = 0 ;

// initialise and read the first number of frames
	y4m_init_frame_info( &in_frame );
	read_error_code = y4m_read_frame(fdIn,inStrInfo,&in_frame,yuv_data[0] );
	
// we will never drop the first frame of a file
	write_error_code = y4m_write_frame( fdOut, outStrInfo, &in_frame, yuv_data[0] );

	for (f=1; f<=drop_frames && Y4M_ERR_EOF != read_error_code; f++) {
		y4m_fini_frame_info( &in_frame );
		y4m_init_frame_info( &in_frame );
		read_error_code = y4m_read_frame(fdIn,inStrInfo,&in_frame,yuv_data[f] );
		++src_frame_counter ;
	}
	
	// l should be drop_frames + 1
	// do some test if fewer frames read and change drop_frames to equal frames read
	
	while( Y4M_ERR_EOF != read_error_code && write_error_code == Y4M_OK ) {

// compare all frames

	for (f=1; f<=drop_frames;f++) {

	// perform frame difference.
	// only comparing Luma, less noise, more resolution... blah blah
	
		bri[f] = 0; bro[f]=0;
		
		for (l=0; l< frame_data_size; l+=w<<1) {
			for (x=0; x<w; x++) {
				bri[f] += abs(yuv_data[f][0][l+x]-yuv_data[f-1][0][l+x]);
				bro[f] += abs(yuv_data[f][0][l+x+w]-yuv_data[f-1][0][l+x+w]);
			}
		}


	}
	
	// find the minimum difference field.

		if (interlacing == Y4M_ILACE_NONE) {
		
			mini = bri[1] + bro[1]; dropmi = 1;
			for (f=2; f<=drop_frames; f++) {
				if (mini > (bri[f]+bro[f])) {
					mini = bri[f]+bro[f];
					dropmi=f;
				}
			}
		
		} else {
			mini = bri[1]; dropmi=1;
			mino = bro[1]; dropmo=1;
			for (f=2; f<=drop_frames; f++) {
				if (mini > bri[f]) {
					mini = bri[f];
					dropmi=f;
				}
				if (mino > bro[f]) {
					mino = bro[f];
					dropmo=f;
				}
			}
		}
// for progressive dropmi and dropmo *should* be the same.

	if (interlacing == Y4M_ILACE_NONE) {
		mjpeg_info("Dropping frame: %d",dropmi);
		for (f=1; f<=drop_frames;f++) {
			if (f != dropmi) {
					write_error_code = y4m_write_frame( fdOut, outStrInfo, &in_frame, yuv_data[f] );
			}
		}
	} else {
		mjpeg_info("Dropping fields even: %d odd: %d",dropmi,dropmo);
		for (f=1; f<=drop_frames;f++) {
		//  if dropmi == dropme, same effect as progressive
			if (dropmi == dropmo) {
				if (f != dropmi) {
					write_error_code = y4m_write_frame( fdOut, outStrInfo, &in_frame, yuv_data[f] );
				}
			} else if ((f == dropmi)||(f == dropmo)) {
				if (f != drop_frames) {
					// shuffle all feilds from next frame to this frame
					for (l=f; l<drop_frames; l++) {
						if (f == dropmi) {
							copyfield (0,w , h, yuv_data[l+1],yuv_data[l]);
						} else {
							copyfield (1,w , h, yuv_data[l+1],yuv_data[l]);
						}
					}
					write_error_code = y4m_write_frame( fdOut, outStrInfo, &in_frame, yuv_data[f] );	
				}
					
			} else {
				write_error_code = y4m_write_frame( fdOut, outStrInfo, &in_frame, yuv_data[f] );
			}
		}
	}
// output all but the minimum difference frame.
//  how do I drop a single field from two different frames

// the additional frame is for comparing to the next block of frames
// we do not want to write it twice

	
	// copy the last frame to the first
	
	for (l=0; l< frame_data_size; l++) {
		yuv_data[0][0][l] = yuv_data[drop_frames][0][l];
		if (!l%2) {
			yuv_data[0][1][l>>2] = yuv_data[drop_frames][1][l>>2];
			yuv_data[0][2][l>>2] = yuv_data[drop_frames][2][l>>2];
		}
	}

	for (f=1; f<=drop_frames && Y4M_ERR_EOF != read_error_code; f++) {
		y4m_fini_frame_info( &in_frame );
		y4m_init_frame_info( &in_frame );
		read_error_code = y4m_read_frame(fdIn,inStrInfo,&in_frame,yuv_data[f] );
		++src_frame_counter ;
	}
     
	  
    }
  // Clean-up regardless an error happened or not

y4m_fini_frame_info( &in_frame );

	for (f=0; f< drop_frames; f++) {
		free( yuv_data[f][0] );
		free( yuv_data[f][1] );
		free( yuv_data[f][2] );
	}
	
  if( read_error_code != Y4M_ERR_EOF )
    mjpeg_error_exit1 ("Error reading from input stream!");
  if( write_error_code != Y4M_OK )
    mjpeg_error_exit1 ("Error writing output stream!");

}

static int parse_interlacing(char *str)
{
  if (str[0] != '\0' && str[1] == '\0')
  {
    switch (str[0])
    {
      case 'p':
        return Y4M_ILACE_NONE;
      case 't':
        return Y4M_ILACE_TOP_FIRST;
      case 'b':
        return Y4M_ILACE_BOTTOM_FIRST;
    }
  }
  mjpeg_error_exit1("Valid interlacing modes are: p - progressive, t - top-field first, b - bottom-field first");
  return Y4M_UNKNOWN; /* to avoid compiler warnings */
}

//
// Returns the greatest common divisor (GCD) of the input parameters.
//
static int gcd(int a, int b)
{
  if (b == 0)
    return a;
  else
    return gcd(b, a % b);
}


// *************************************************************************************
// MAIN
// *************************************************************************************
int main (int argc, char *argv[])
{

	int verbose = 4; // LOG_ERROR ;
	int drop_frames = 0;
	int fdIn = 0 ;
	int fdOut = 1 ;
	y4m_stream_info_t in_streaminfo,out_streaminfo;
	int src_interlacing = Y4M_UNKNOWN;
	y4m_ratio_t src_frame_rate;
	const static char *legal_flags = "F:I:v:h";
	int c ;

  while ((c = getopt (argc, argv, legal_flags)) != -1) {
    switch (c) {
      case 'v':
        verbose = atoi (optarg);
        if (verbose < 0 || verbose > 2)
          mjpeg_error_exit1 ("Verbose level must be [0..2]");
        break;
    case 'I':
	    src_interlacing = parse_interlacing(optarg);
		break;
	case 'F':
		drop_frames = atoi(optarg);
		break;
	case 'h':
	case '?':
          print_usage (argv);
          return 0 ;
          break;
    }
  }
  
	if (drop_frames < 2) 
		mjpeg_error_exit1("Minimum 2 frames to compare");

  
  // mjpeg tools global initialisations
  mjpeg_default_handler_verbosity (verbose);

  // Initialize input streams
  y4m_init_stream_info (&in_streaminfo);
  y4m_init_stream_info (&out_streaminfo);

  // ***************************************************************
  // Get video stream informations (size, framerate, interlacing, aspect ratio).
  // The streaminfo structure is filled in
  // ***************************************************************
  // INPUT comes from stdin, we check for a correct file header
	if (y4m_read_stream_header (fdIn, &in_streaminfo) != Y4M_OK)
		mjpeg_error_exit1 ("Could'nt read YUV4MPEG header!");

	src_frame_rate = y4m_si_get_framerate( &in_streaminfo );
	y4m_copy_stream_info( &out_streaminfo, &in_streaminfo );

	mjpeg_info ("Input framerate %d:%d",src_frame_rate.n,src_frame_rate.d);


	src_frame_rate.d = src_frame_rate.d * drop_frames;
	src_frame_rate.n = src_frame_rate.n * (drop_frames-1);
	
	mjpeg_info( "Output framerate %d:%d\n",src_frame_rate.n,src_frame_rate.d);
	
	  y4m_si_set_framerate( &out_streaminfo, src_frame_rate );


  // Information output
  mjpeg_info ("yuvrfps (version " YUVRFPS_VERSION ") is a frame rate converter which drops doubled frames for yuv streams");
  mjpeg_info ("yuvrfps -h for help, or man yuvaddetect");

if (src_interlacing == Y4M_UNKNOWN)
    src_interlacing = y4m_si_get_interlace(&in_streaminfo);

    
  /* in that function we do all the important work */
	y4m_write_stream_header(fdOut,&out_streaminfo);

	detect( fdIn,&in_streaminfo,fdOut,&out_streaminfo,src_interlacing,drop_frames);

  y4m_fini_stream_info (&in_streaminfo);
  y4m_fini_stream_info (&out_streaminfo);

  return 0;
}
/*
 * Local variables:
 *  tab-width: 8
 *  indent-tabs-mode: nil
 * End:
 */