/*
  
  Convert a transcode subtitle stream to vobsub format

  Author: Arne Driescher

  Copyright:

  Most of the code is stolen from
  mplayer (file vobsub.c) http://mplayer.dev.hu/homepage/news.html 
  and transcode http://www.theorie.physik.uni-goettingen.de/~ostreich/transcode/
  so that the Copyright of the respective owner should be applied.
  (That means GPL.)
  
  Version: 0.01
*/

#include <stdio.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>     
#include "subtitle2pgm.h"
#include <string.h>
#include <unistd.h>  
#include "vobsub.h"

#ifndef MAXFLOAT
#  define MAXFLOAT      3.40282347e+38F 
#endif

#define READ_BUF_SIZE (64*1024)


int vobsub_id=-1;
int verbose=0;
int append=0;
double time_scale_factor=1.0;

// get the major version number from the version code
unsigned int major_version(unsigned int version)
{
    // bit 16-31 contain the major version number
    return version >> 16;
}

unsigned int minor_version(unsigned int version)
{
    // bit 0-15 contain the minor version number
    return version & 0xffff;
}

void remove_old_sub_idx_files(const char* basename)
{
    char sub_file_name[FILENAME_MAX];
    char idx_file_name[FILENAME_MAX];
    struct stat stat_buf;
    int err;

    if(strlen(basename)<1){
	fprintf(stderr,"cannot remove sub/idx files for empty basename\n");
	return;
    }

    // build filename for sub-file
    strcpy(sub_file_name,basename);
    strcat(sub_file_name,".sub");

    // build filename for idx-file
    strcpy(idx_file_name,basename);
    strcat(idx_file_name,".idx");



    err = stat(sub_file_name,&stat_buf);

    if(err){
	switch(errno){
	    case  ENOENT:  // file does not exist, no need to remove it
		break;
	    default:
		perror("stat sub file");
	}
    } else {
	// try to remove the existing sub file
	if( -1 == remove(sub_file_name) ){
	    perror("remove sub file");
	} else {
	    if(verbose){
		fprintf(stderr,"sub file %s removed\n",sub_file_name);
	    }
	}
    }
  
    err = stat(idx_file_name,&stat_buf);

    if(err){
	switch(errno){
	    case  ENOENT:  // file does not exist, no need to remove it
		break;
	    default:
		perror("stat idx file");
	}
    } else {
	// try to remove the existing sub file
	if( -1 == remove(idx_file_name) ){
	    perror("remove idx file");
	} else {
	    if(verbose){
		fprintf(stderr,"idx file %s removed\n",idx_file_name);
	    }
	}
    }
}

void usage(void)
{
    fprintf(stderr,"\n\t Convert a transcode subtitle stream to vobsub format \n\n");
    fprintf(stderr,"\t subtitle2vonsub [options]\n");
    fprintf(stderr,"\t -p <input file name> of transcode ps1 file\n");
    fprintf(stderr,"\t -i <input file name> of ifo file\n");
    fprintf(stderr,"\t -o <output file base> name\n");
    fprintf(stderr,"\t -s <width,height> set the default movie size if ifo-file is missing\n");
    fprintf(stderr,"\t -c <up to 16 hex values> set color palette if ifo-file is missing\n");
    fprintf(stderr,"\t -e <start,end,new_start> extract only part of file (parameters in seconds)\n");
    fprintf(stderr,"\t -a append to existing sub and idx files\n");
    fprintf(stderr,"\t -t <factor> time scale factor\n");
    fprintf(stderr,"\t -v verbose output\n");
    fprintf(stderr,"\t Version 0.3 (alpha) for >transcode-0.6.0\n");
    exit(0);
}


// magic string (definition must match the one in transcode/import/extract_ac3.c)
static char *subtitle_header_str="SUBTITLE";

int main(int argc, char** argv)
{
    
    int len;
    char read_buf[READ_BUF_SIZE];
    char output_base_name[FILENAME_MAX];
    char input_file_name[FILENAME_MAX];
    char ifo_file_name[FILENAME_MAX];

    subtitle_header_v3_t subtitle_header;
    int ch,n;
    int skip_len;
    double pts_seconds=0.0;
    unsigned int show_version_mismatch=~0;
    double layer_skip_adjust=0.0;
    double layer_skip_offset=0.0;
    unsigned int discont_ctr=0;

    // default color palette
    unsigned int palette[16]={0x101010, 0x6e6e6e, 0xcbcbcb, 0x202020, 0x808080, 0x808080, 
			      0x808080, 0x808080, 0x808080, 0x808080, 0x808080, 0x808080, 
			      0xb4b4b4, 0x101010, 0xe4e4e4, 0x808080};
    // assume PAL DVD size: 720x576 if no IFO was found
    unsigned int width=720;
    unsigned int height=576;
    unsigned char lang_abrv[3] = { 'e', 'n', 0 };
    unsigned int vobsub_out_index=0;
    int dvdsub_id=0; //FIXME 
    void *vobsub_writer=NULL;
    double extract_start_pts=0.0;
    double extract_end_pts= MAXFLOAT;
    double extract_output_start_pts=0.0;
    double output_pts=0.0;

    /* initialize default values here that can be overriden by commandline arguments */

    // default filenames used for input/output
    strcpy(output_base_name,"movie_subtitle");
    strcpy(ifo_file_name,"movie.ifo");
    strcpy(input_file_name,"movie.ps1");

    /* scan command line arguments */
    opterr=0;
    while ((ch = getopt(argc, argv, "vt:s:p:i:c:e:o:ah")) != -1) {
      
	switch (ch) {

	    // color palette
	    case 'c': 
		n = sscanf(optarg,"%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x", 
			   &palette[0], &palette[1], &palette[2], &palette[3],
			   &palette[4], &palette[5], &palette[6], &palette[7],
			   &palette[8], &palette[9], &palette[10], &palette[11],
			   &palette[12], &palette[13], &palette[14], &palette[15]);
		if(n<1 || n>16) {
		    fprintf(stderr,"invalid argument to color palette option\n");
		    exit(-1);
		}
		break;


	    case 'e':  // extract only a part 
		n = sscanf(optarg,"%lf,%lf,%lf", &extract_start_pts, &extract_end_pts,&extract_output_start_pts);
		if(n==0) {
		    fprintf(stderr,"Invalid parameter for -e option\n");
		    exit(1);
		}
		if(extract_start_pts<0){
		    fprintf(stderr,"negativ start pts not allowed for -e option\n");
		    exit(-1);
		}

		if(extract_end_pts<0){
		    fprintf(stderr,"negativ end pts not allowed for option -e\n");
		    exit(-1);
		}
		if(extract_output_start_pts<0){
		    fprintf(stderr,"warning: Negativ pts for output given to -e option. Check your results!\n");
		}
	
		if(verbose)
		    fprintf(stderr,"Extracting from %f. to %f and setting initial pts to %f \n",
			    extract_start_pts,
			    extract_end_pts,
			    extract_output_start_pts);
		break;

	    case 's':  // set default size to -s width,height if no ifo file is avalable 
		n = sscanf(optarg,"%d,%d", &width, &height);
		if( (n<1) || (n>2) ) {
		    fprintf(stderr,"Invalid parameter for -s width,height option\n");
		    exit(1);
		}
	
	    case 'o':
		n = sscanf(optarg,"%s", output_base_name);
	
		if(n!=1) {
		    fprintf(stderr,"no filename specified to option -o\n");
		    exit(1);
		}
		break;
      
	    case 'i':
		n = sscanf(optarg,"%s",ifo_file_name);
	
		if(n!=1) {
		    fprintf(stderr,"no filename specified to option -i\n");
		    exit(1);
		}
		break;

	    case 'p':
		n = sscanf(optarg,"%s", input_file_name);
	
		if(n!=1) {
		    fprintf(stderr,"no filename specified to option -p\n");
		    exit(1);
		} 
		// open the specified input file for reading
		if( !(freopen(input_file_name,"r",stdin)) ){
		    perror("stdin redirection");
		    fprintf(stderr,"Tried to open %s for input\n",input_file_name);
		    exit(1);
		}
	  
		break;
	  
	    case 't':
		n = sscanf(optarg,"%lf", &time_scale_factor);
		if(n<1){
		    fprintf(stderr,"Argument to -t option not given\n");
		    exit(1);
		}
		if(verbose){
		    fprintf(stderr,"Scaling time by %f\n",
			    time_scale_factor);
		}
		break;
	    case 'a':
		append=1; // do not delete the old files
		break;
	    case 'h':
		usage();
		break;

	    case 'v':
		verbose=1;
		break;
	    default:
		fprintf(stderr,"Unknown option. Use -h for list of valid options.\n");
		exit(1);
	}
    }

    // parse the ifo file to get subtitle picture size and color palette
    if(vobsub_parse_ifo(NULL,ifo_file_name, palette, &width, &height, 1, dvdsub_id, lang_abrv)>=0){
	if(verbose){
	    fprintf(stderr,"reading IFO file was sucessful\n");
	}
    } else {
	fprintf(stderr,"Opening ifo file failed. I tried to open %s but got an error.\n",
		ifo_file_name);
	fprintf(stderr,"Using default or command line arguments "
		"for palette, width and hight instead\n");
    }

    // delete existing sub/idx files if append mode is not requested
    if(append){
	if(verbose){
	    fprintf(stderr,"Append mode for existing sub/idx files assumed\n");
	}
    } else {
	remove_old_sub_idx_files(output_base_name);
    }

    // open the vobsub output file
    vobsub_writer = vobsub_out_open(output_base_name, palette, width, height,
				    lang_abrv, vobsub_out_index);

    if(!vobsub_writer){
	fprintf(stderr,"vobsub_writer instance not created.\n");
	exit(-1);
    }

    if(verbose){
	fprintf(stderr,"Using width:%d height:%d language:%s vobsub index:%d\n",
		width, 
		height,
		lang_abrv,
		vobsub_out_index);
    }

    // process all packages in the stream
    // the stream is an "augmented" raw subtitle stream
    // where two additional headers are used.
    while(1){
    
	// read the magic "SUBTITLE" identified
	len=fread(read_buf, strlen(subtitle_header_str),1, stdin);

	if(feof(stdin)){
	    break;
	}

	if(len != 1){

	    fprintf(stderr,"Could not read magic header %s\n", subtitle_header_str);
	    perror("Magic header");
	    exit(1);
	}
	if(strncmp(read_buf,subtitle_header_str,strlen(subtitle_header_str))){
	    fprintf(stderr,"Header %s not found\n",subtitle_header_str);
	    fprintf(stderr,"%s\n",read_buf);
	    exit(1);
	}
    
	// read the real header
	len=fread(&subtitle_header, sizeof(subtitle_header_v3_t), 1, stdin);
    
	if(len != 1){
	    fprintf(stderr,"Could not read subtitle header\n");
	    perror("Subtitle header");
	    exit(1);
	}


	// check for version mismatch and warn the user
	if( (subtitle_header.header_version < MIN_VERSION_CODE) && show_version_mismatch){
	    fprintf(stderr,"Warning: subtitle2pgm was compiled for header version %u.%u"
		    " and the stream was produced with version %u.%u.\n",
		    major_version(MIN_VERSION_CODE), 
		    minor_version(MIN_VERSION_CODE),
		    major_version(subtitle_header.header_version),
		    minor_version(subtitle_header.header_version));
	    // don't show this message again
	    show_version_mismatch=0;
	}

	// we only try to proceed if the major versions match
	if( major_version(subtitle_header.header_version) != major_version(MIN_VERSION_CODE) ){
	    fprintf(stderr,"Versions are not compatible. Please extract subtitle stream\n"
		    " with a newer transcode version\n");
	    exit(1);
	}


	// calculate exessive header bytes
	skip_len = subtitle_header.header_length - sizeof(subtitle_header_v3_t);

	// handle versions mismatch
	if(skip_len){

	    // header size can only grow (unless something nasty happend)
	    assert(skip_len > 0);

	    // put the rest of the header into read buffer
	    len = fread(read_buf, sizeof(char), skip_len, stdin);
      
	    if(len != skip_len){
		perror("Header skip:");
		exit(1);
	    }
	}
    
	/* depending on the minor version some additional information might
	   be available. */

	// since version 3.1 discont_ctr is available but works only sine 4-Mar-2002. Allow extra
	// adjustment if requested.
	if(minor_version(subtitle_header.header_version) > 1){
	    discont_ctr=*((unsigned int*) read_buf);
	    layer_skip_adjust = discont_ctr*layer_skip_offset;
	}
   


	// debug output
#ifdef DEBUG
        fprintf(stderr,"subtitle_header: length=%d version=%0x lpts=%u (%f), rpts=%f, payload=%d, discont=%d\n",
		subtitle_header.header_length,
		subtitle_header.header_version,
		subtitle_header.lpts,
		(double)(subtitle_header.lpts/300)/90000.0,
		subtitle_header.rpts,
		subtitle_header.payload_length,
		discont_ctr);
#endif
    
	// read one byte subtitle stream id (should match the number given to tcextract -a)
	len=fread(read_buf, sizeof(char), 1, stdin);
	if(len != 1){
	    perror("stream id");
	    exit(1);
	}
	// debug output
	//fprintf(stderr,"stream id: %x \n",(int)*read_buf);


	// read numer of bytes given in header
	len = fread(read_buf, subtitle_header.payload_length-1, 1, stdin);

    
	if(len >0){
	    if(subtitle_header.rpts > 0){
		// if rpts is something useful take it
		pts_seconds=subtitle_header.rpts;
	    } else {
		// calculate the time from lpts
		fprintf(stderr, "fallback to lpts!\n");
		pts_seconds = (double)(subtitle_header.lpts/300)/90000.0;
	    }

	    // add offset for layer skip
	    pts_seconds += layer_skip_adjust;

      
	    // output only in the requested range (-e option)
	    if( (extract_start_pts <= pts_seconds) && (extract_end_pts >= pts_seconds) ){ 
		output_pts = pts_seconds - extract_start_pts + extract_output_start_pts;
		// scale time if requested (-t option)
		output_pts *= time_scale_factor;
		vobsub_out_output(vobsub_writer,read_buf, subtitle_header.payload_length-1,output_pts);
	    }
	} else {
	    perror("Input file processing finished");
	    exit(errno);
	}
    }

    if(verbose){
	fprintf(stderr,"Conversion finished\n");
    }

    vobsub_out_close(vobsub_writer);

    return 0;
}