path: root/mot-encoder.c

/*
    Copyright (C) 2014 CSP Innovazione nelle ICT s.c.a r.l. (http://rd.csp.it/)

    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 3 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, see <http://www.gnu.org/licenses/>.

    MotEncoder.c
          Generete PAD data for MOT Slideshow and DLS

    Authors:
         Sergio Sagliocco <sergio.sagliocco@csp.it> 
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <wand/magick_wand.h>

#include "lib_crc.h"

#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)>(b))?(a):(b))

#define MAXSEGLEN 8179
#define MAXDLS 129

typedef unsigned char UCHAR;
typedef unsigned short int USHORT;

typedef struct {
    // MSC Data Group Header (extension field not supported)
    unsigned char extflag;      //  1 bit
    unsigned char crcflag;      //  1 bit
    unsigned char segflag;      //  1 bit
    unsigned char accflag;      //  1 bit
    unsigned char dgtype;       //  4 bits
    unsigned char cindex;       //  4 bits
    unsigned char rindex;       //  4 bits
    /// Session header - Segment field
    unsigned char last;         //  1 bit
    unsigned short int segnum;      // 16 bits
    // Session header - User access field
    unsigned char rfa;          //  3 bits
    unsigned char tidflag;      //  1 bit
    unsigned char lenid;        //  4 bits - Fixed to value 2 in this implemntation
    unsigned short int tid;     // 16 bits
    // MSC data group data field
    //  Mot Segmentation header
    unsigned char rcount;       //  3 bits
    unsigned short int seglen;      // 13 bits
    // Mot segment
    unsigned char* segdata;
    // MSC data group CRC
    unsigned short int crc;     // 16 bits
} MSCDG;
/*
   typedef struct {
// MOT HEADER CUSTOMIZED FOR SLIDESHOW APP
unsigned int bodysize;      // 28 bits
unsigned short int headsize;    // 13 bits
unsigned char ctype;        //  6 bits
unsigned char sctype;       //  9 bits
unsigned char triggertime[5];   // 0x85 0x00 0x00 0x00 0x00 => NOW
unsigned char contname[14];     // 0xCC 0x0C 0x00 imgXXXX.jpg
} MOTSLIDEHDR;
*/
int encodeFile (char* fname, int fidx, int padlen);
void createMotHeader(size_t blobsize, int fidx, char* mothdr, int* mothdrlen);
void createMscDG(MSCDG* msc, unsigned short int dgtype, unsigned short int cindex, unsigned short int lastseg, unsigned short int tid, unsigned char* data, unsigned short int datalen);
void packMscDG(unsigned char* mscblob, MSCDG* msc, unsigned short int *bsize);
void writeMotPAD(unsigned char* mscdg, unsigned short int mscdgsize, unsigned short int padlen);
void create_dls_datagroup (char* text, int padlen, unsigned char*** p_dlsdg, int* p_numdg);
void writeDLS(int padlen);

void usage(char* name)
{
    fprintf(stderr, "DAB MOT encoder\n"
                    "for slideshow and DLS\n\n"
                    "By CSP Innovazione nelle ICT s.c.a r.l. (http://rd.csp.it/)\n\n"
                    "Reads image data from the specified directory, and outputs PAD data\n"
                    "on standard output\n"
                    "Reads DLS from /tmp/dls.file\n");
    fprintf(stderr, "Usage: %s <dirname>\n", name);
}

int main (int argc, char *argv[])
{
    int len,fidx,ret;
    struct dirent *pDirent;
    DIR *pDir;
    char imagepath[128];
    char dlstext[MAXDLS],dlstextprev[MAXDLS];
    int padlen=53;


    if (argc < 2) {
        usage(argv[0]);
        return 0;
    }

    MagickWandGenesis();

    fidx=0;
    while(1) {
        pDir = opendir (argv[1]);
        if (pDir == NULL) {
            printf ("Cannot open directory '%s'\n", argv[1]);
            return 1;
        }
        if (fidx == 9999) fidx=0;
        while ((pDirent = readdir(pDir)) != NULL) {
            if (pDirent->d_name[0]!='.') {
                sprintf (imagepath,"%s/%s",argv[1],pDirent->d_name);
                ret=encodeFile(imagepath, fidx, padlen);
                if (ret!=1) {
                    fprintf(stderr,"Error - Cannot encode file %s\n",pDirent->d_name);
                } else {
                    fidx++;
                    writeDLS(padlen);
                    sleep(10);
                }
            }
        }
        closedir (pDir);
    }
    return 1;
}

int encodeFile (char* fname, int fidx, int padlen)
{
    int fd=0,ret,mothdrlen,nseg,lastseglen,i,last,curseglen;
    unsigned char mothdr[32];
    MagickWand *m_wand = NULL;
    PixelWand  *p_wand = NULL;
    size_t blobsize,height,width;
    unsigned char *blob = NULL, *curseg = NULL;
    MagickBooleanType err;
    MSCDG msc;
    unsigned char mscblob[8200];
    unsigned short int mscblobsize;
    //float aspectRatio;


    m_wand = NewMagickWand();
    p_wand = NewPixelWand();
    PixelSetColor(p_wand,"black");

    err = MagickReadImage(m_wand,fname);
    if (err==MagickFalse) {
        fprintf(stderr,"Error - Unable to load image %s\n",fname);
        ret=0;
        goto RETURN;
    }

    height=MagickGetImageHeight(m_wand);
    width=MagickGetImageWidth(m_wand);
    //aspectRatio = (width * 1.0)/height;

    fprintf(stderr,"Image: %s (id=%d). Original size: %d x %d. ",fname,fidx,width,height);

    while (height>240 || width>320) {
        if (height/240.0 > width/320.0) {
            //width = height * aspectRatio;
            width = width * 240.0 / height;
            height = 240;
        }
        else {
            //height = width * (1.0/aspectRatio);
            height = height * 320.0 / width;
            width = 320;
        }
        MagickResizeImage(m_wand,width,height,LanczosFilter,1);
    }



    height=MagickGetImageHeight(m_wand);
    width=MagickGetImageWidth(m_wand);

    MagickBorderImage(m_wand,p_wand,(320-width)/2,(240-height)/2);

    MagickSetImageCompressionQuality(m_wand,75);
    MagickSetImageFormat(m_wand,"jpg");
    blob=MagickGetImagesBlob(m_wand, &blobsize);
    fprintf(stderr,"Resized to %d x %d. Size after compression %d bytes\n",width,height,blobsize);

    nseg=blobsize / MAXSEGLEN;
    lastseglen=blobsize % MAXSEGLEN;
    if (lastseglen !=0) nseg++;

    createMotHeader(blobsize,fidx,mothdr,&mothdrlen);
    // Create the MSC Data Group C-Structure
    createMscDG(&msc,3,0,1,fidx,mothdr,mothdrlen);
    // Generate the MSC DG frame (Figure 9 en 300 401)
    packMscDG(mscblob,&msc,&mscblobsize);
    writeMotPAD(mscblob,mscblobsize,padlen);

    for (i=0;i<nseg;i++) {
        curseg=blob+i*MAXSEGLEN;
        if (i==nseg-1) {
            curseglen=lastseglen;
            last=1;
        }
        else { 
            curseglen=MAXSEGLEN;
            last=0;
        }

        createMscDG(&msc,4,i,last,fidx,curseg,curseglen);
        packMscDG(mscblob,&msc,&mscblobsize);
        writeMotPAD(mscblob,mscblobsize,padlen);
    }

    ret=1;

RETURN:
    if (m_wand) {
        m_wand = DestroyMagickWand(m_wand);
    }
    if (blob) {
        free(blob);
    }
    return ret;
}


void createMotHeader(size_t blobsize, int fidx, char* mothdr,int* mothdrlen)
{
    int ret;
    struct stat s;
    char MotHeaderCore[7]= {0x00,0x00,0x00,0x00,0x0D,0x04,0x01};
    char MotHeaderExt[19]= {0x85,0x00,0x00,0x00,0x00,0xcc,0x0c,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
    char cntemp[12];
    int i;

    MotHeaderCore[0]=(blobsize<<4 & 0xFF000000)>>24;
    MotHeaderCore[1]=(blobsize<<4 & 0x00FF0000)>>16;
    MotHeaderCore[2]=(blobsize<<4 & 0x0000FF00)>>8;
    MotHeaderCore[3]=(blobsize<<4 & 0x000000FF);

    sprintf(cntemp,"img%04d.jpg",fidx);
    for (i=0; i<sizeof(cntemp); i++) {
        MotHeaderExt[8+i]=cntemp[i];
    }
    *mothdrlen=26;
    for (i=0;i<7;i++)
        mothdr[i]=MotHeaderCore[i];
    for (i=0;i<19;i++)
        mothdr[7+i]=MotHeaderExt[i];

    return;
}

void createMscDG(MSCDG* msc, unsigned short int dgtype, unsigned short int cindex, unsigned short int lastseg, unsigned short int tid, unsigned char* data, unsigned short int datalen)
{
    msc->extflag=0;
    msc->crcflag=1;
    msc->segflag=1;
    msc->accflag=1;
    msc->dgtype=dgtype; 
    msc->cindex=cindex;
    msc->rindex=0;
    msc->last=lastseg;
    msc->segnum=cindex;
    msc->rfa=0;
    msc->tidflag=1;
    msc->lenid=2;
    msc->tid=tid;
    msc->segdata=data;
    msc->rcount=0;
    msc->seglen=datalen;

    return;
}


void packMscDG(unsigned char* b, MSCDG* msc, unsigned short int* bsize) {

    int i;
    unsigned short int crc=0xFFFF;

    b[0]=(msc->extflag<<7)|(msc->crcflag<<6)|(msc->segflag<<5)|(msc->accflag<<4)|msc->dgtype;
    b[1]=(msc->cindex<<4)|msc->rindex;
    b[2]=(msc->last<<7)|((msc->segnum & 0x7F00)>>8);
    b[3]=msc->segnum & 0x00FF;
    b[4]=0;
    b[4]=(msc->rfa<<5)|(msc->tidflag<<4)|msc->lenid;
    b[5]=(msc->tid & 0xFF00)>>8;
    b[6]=msc->tid & 0x00FF;
    b[7]=(msc->rcount<<5)|((msc->seglen & 0x1F00)>>8);
    b[8]=msc->seglen & 0x00FF;

    for (i=0;i<9;i++)
        crc = update_crc_ccitt(crc, b[i]);

    for(i=0;i<msc->seglen;i++) {
        b[i+9]=(msc->segdata)[i];
        crc = update_crc_ccitt(crc, b[i+9]);
    }

    crc=~crc;
    b[9+msc->seglen] = (crc & 0xFF00) >> 8;     // HI CRC
    b[9+msc->seglen+1] = crc & 0x00FF;          // LO CRC

    *bsize=9+msc->seglen+1+1;

    //write(1,b,9+msc->seglen+1+1);

}


void writeMotPAD(unsigned char* mscdg, unsigned short int mscdgsize, unsigned short int padlen) {

    unsigned char pad[128];
    int xpadlengthmask,i,j,numseg,lastseglen;
    unsigned short int crc;


    if (padlen==17)
        xpadlengthmask=3;
    else if (padlen==21)
        xpadlengthmask=4;
    else if (padlen==29)
        xpadlengthmask=5;
    else if (padlen==37)
        xpadlengthmask=6;
    else if (padlen==53)
        xpadlengthmask=7;


    // Write Data Group Length Indicator
    crc = 0xffff;
    pad[padlen-1]=0x02;                                                        // FF-PAD Byte L (CI=1)
    pad[padlen-2]=0x20;                                                        // FF-PAD Byte L-1 (Variable size X_PAD)
    pad[padlen-3]=(xpadlengthmask<<5) | 0x01;                                  // CI => data length = 12 (011) - Application Type=2 (DLS - start of X-PAD data group)
    pad[padlen-4]=0x00;                                                        // End of CI list
    pad[padlen-5]=(mscdgsize & 0x3F00)>>8;                     // RFA+HI Data group length
    pad[padlen-6]=(mscdgsize & 0x00FF); 
    crc = update_crc_ccitt(crc, pad[padlen-5]);
    crc = update_crc_ccitt(crc, pad[padlen-6]);
    crc = ~crc;
    pad[padlen-7]=(crc & 0xFF00) >> 8;                         // HI CRC
    pad[padlen-8]=(crc & 0x00FF);                                          // LO CRC
    for (i=padlen-9;i>=0;i--) {                                    // NULL PADDING
        pad[i]=0x00;
    }   
    write(STDOUT_FILENO,pad,padlen);
    //fprintf(stderr,"Data Group Length Indicator: ");
    //for (i=0;i<padlen;i++) fprintf(stderr,"%02x ",pad[i]);
    //fprintf(stderr,"\n");

    // Write MSC Data Groupsd
    numseg=mscdgsize / (padlen-5);
    lastseglen=mscdgsize % (padlen-5);
    if (lastseglen > 0) {
        numseg++;              // The last incomplete segment
    }

    for (i=0;i<numseg;i++) {

        char* curseg;
        int curseglen;
        UCHAR firstseg;

        curseg = &mscdg[i*(padlen-5)];
        //fprintf(stderr,"Segment number %d\n",i+1);

        if (i==0)               // First segment
            firstseg=1;
        else
            firstseg=0;

        if (i==numseg-1) {      //Last segment
            if (lastseglen!=0)
                curseglen=lastseglen;
            else
                curseglen=padlen-5;
        } else {
            curseglen=padlen-5;
        }

        pad[padlen-1]=0x02;                                                        // FF-PAD Byte L (CI=1)
        pad[padlen-2]=0x20;                                                        // FF-PAD Byte L-1 (Variable size X_PAD)
        if (firstseg==1)
            pad[padlen-3]=(xpadlengthmask<<5) | 12;                                  // CI => data length = 12 (011) - Application Type=12 (start of MOT)
        else
            pad[padlen-3]=(xpadlengthmask<<5) | 13;                                  // CI => data length = 12 (011) - Application Type=13 (MOT)

        pad[padlen-4]=0x00;                                                        // End of CI list

        for (j=0; j<curseglen; j++)
            pad[padlen-5-j]=curseg[j];
        for (j=padlen-5-curseglen;j>=0;j--)
            pad[j]=0x00;

        write(STDOUT_FILENO,pad,padlen);
        //fprintf(stderr,"MSC Data Group - Segment %d: ",i);
        //for (j=0;j<padlen;j++) fprintf(stderr,"%02x ",pad[j]);
        //        fprintf(stderr,"\n");

    }
}


void writeDLS(int padlen) {
    char dlstext[MAXDLS];
    static char dlstextprev[MAXDLS]; 
    int dlslen,i;
    static unsigned char** dlsdg;
    static int numdg=0;

    static int dlsfd=0;

    if (dlsfd!=0) close(dlsfd);
    dlsfd=open("/tmp/dls.file",O_RDONLY);
    if (dlsfd==-1) {
        fprintf(stderr,"Error - Cannot open dls file\n");
        return;
    }

    dlslen=read(dlsfd, dlstext, MAXDLS);
    dlstext[dlslen]=0x00;
    //if (strcmp(dlstext,dlstextprev)!=0) {
    create_dls_datagroup(dlstext,padlen,&dlsdg,&numdg);
    strcpy(dlstextprev,dlstext);
    //}
    for (i=0;i<numdg;i++) {
        write(STDOUT_FILENO,dlsdg[i],padlen);
    }

}

void create_dls_datagroup (char* text, int padlen, UCHAR*** p_dlsdg, int* p_numdg) {

    UCHAR dlsseg[8][16];                            // max 8 segments, each max 16 chars
    UCHAR** dlsdg;                                  // Array od datagroups composing dls text;


    int numseg;                                     // Number of DSL segments
    int lastseglen;                                 // Length of the last segment
    int numdg;                                      // Number of data group
    int xpadlengthmask;
    int i,j,k,z,idx_start_crc,idx_stop_crc;
    USHORT dlscrc;
    static UCHAR toggle=0;

    if (toggle==0)
        toggle=1;
    else
        toggle=0;

    numseg=strlen(text) / 16;
    lastseglen=strlen(text) % 16;
    if (padlen-9 >= 16) {
        if (lastseglen > 0) numseg++;           // The last incomplete segment
        numdg=numseg;           // The PAD can contain the full segmnet and overhead (9 bytes)
    } else {
        numdg=numseg*2;         // Each 16 char segment span over 2 dg
        if (lastseglen > 0) {
            numseg++;              // The last incomplete segment
            if (lastseglen <= padlen-9)
                numdg+=1;
            else
                numdg+=2;

        }
    }
    *p_numdg=numdg;
    fprintf(stderr,"PAD Length: %d\n",padlen);
    fprintf(stderr,"DLS text: %s\n",text);
    fprintf(stderr,"Number od DLS segments: %d\n",numseg);
    fprintf(stderr,"Number od DLS data grupus: %d\n",numdg);

    if (padlen==17)
        xpadlengthmask=3;
    else if (padlen==21)
        xpadlengthmask=4;
    else if (padlen==29)
        xpadlengthmask=5;
    else if (padlen==37)
        xpadlengthmask=6;
    else if (padlen==53)
        xpadlengthmask=7;

    *p_dlsdg = (UCHAR**) malloc(numdg*sizeof(UCHAR*));
    dlsdg=*p_dlsdg;

    i=0;
    for (z=0;z<numseg;z++) {

        char* curseg;
        int curseglen;
        UCHAR firstseg,lastseg;

        curseg = &text[z*16];
        fprintf(stderr,"Segment number %d\n",z+1);

        if (z==0)               // First segment
            firstseg=1;
        else
            firstseg=0;

        if (z==numseg-1) {      //Last segment
            if (lastseglen!=0)
                curseglen=lastseglen;
            else
                curseglen=16;
            lastseg=1;
        } else {
            curseglen=16;
            lastseg=0;
        }

        if (curseglen<=padlen-9) {                                                              // Segment is composed by 1 data group
            dlsdg[i]=(UCHAR*) malloc(padlen*sizeof(UCHAR));
            dlsdg[i][padlen-1]=0x02;                                                        // FF-PAD Byte L (CI=1)
            dlsdg[i][padlen-2]=0x20;                                                        // FF-PAD Byte L-1 (Variable size X_PAD)
            dlsdg[i][padlen-3]=(xpadlengthmask<<5) | 0x02;                                  // CI => data length = 12 (011) - Application Type=2 (DLS - start of X-PAD data group)
            dlsdg[i][padlen-4]=0x00;                                                        // End of CI list

            dlsdg[i][padlen-5]=((toggle*8+firstseg*4+lastseg*2+0)<<4) | (curseglen-1);      // DLS Prefix (T=1,Only one segment,segment length-1)

            if (firstseg==1)
                dlsdg[i][padlen-6]=0x00;                                                 // DLS Prefix (Charset standard)
            else
                dlsdg[i][padlen-6]=z<<4;                                                // DLS SegNum

            idx_start_crc = padlen-5;                                                       // CRC start from prefix
            for (j=0;j<curseglen;j++) {                                                      // DLS text
                dlsdg[i][padlen-7-j]=curseg[j];
            }

            idx_stop_crc = padlen-7-curseglen+1;

            dlscrc = 0xffff;
            for (j=idx_start_crc;j>=idx_stop_crc;j--) {
                dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][j]);
            }

            dlscrc = ~dlscrc;
            fprintf(stderr,"crc=%x ~crc=%x\n",~dlscrc,dlscrc);

            dlsdg[i][padlen-7-curseglen] = (dlscrc & 0xFF00) >> 8;     // HI CRC
            dlsdg[i][padlen-7-curseglen-1] = dlscrc & 0x00FF;          // LO CRC

            for (j=padlen-7-curseglen-2;j>=0;j--) {                    // NULL PADDING
                dlsdg[i][j]=0x00;
            }
            fprintf(stderr,"Data group: ");
            for (j=0;j<padlen;j++) fprintf(stderr,"%x ",dlsdg[i][j]);
            fprintf(stderr,"\n");
            i++;

        } else {                        // Segment is composed by 2 data groups

            // FIRST DG (NO CRC)
            dlscrc = 0xffff;

            dlsdg[i]=(UCHAR*) malloc(padlen*sizeof(UCHAR));
            dlsdg[i][padlen-1]=0x02;                                // FF-PAD Byte L (CI=1)
            dlsdg[i][padlen-2]=0x20;                                // FF-PAD Byte L-1 (Variable size X_PAD)
            dlsdg[i][padlen-3]=(xpadlengthmask<<5) | 0x02;          // CI => data length = 12 (011) - Application Type=2 (DLS - start of X-PAD data group)
            dlsdg[i][padlen-4]=0x00;                                // End of CI list
            dlsdg[i][padlen-5]=((toggle*8+firstseg*4+lastseg*2+0)<<4) | (curseglen-1);      // DLS Prefix (T=1,Only one segment,segment length-1)

            if (firstseg==1)
                dlsdg[i][padlen-6]=0x00;                                                 // DLS Prefix (Charset standard)
            else
                dlsdg[i][padlen-6]=(i-1)<<4;                                            // DLS SegNum

            dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][padlen-5]);
            dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][padlen-6]);

            for (j=0;j < MIN(curseglen,padlen-7); j++) {                                // DLS text
                dlsdg[i][padlen-7-j]=curseg[j];
                dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][padlen-7-j]);
            }
            k=j;
            if (curseglen==padlen-8) {                                      // end of segment
                dlscrc = ~dlscrc;
                dlsdg[i][1] = (dlscrc & 0xFF00) >> 8;     // HI CRC
                fprintf(stderr,"crc=%x ~crc=%x\n",~dlscrc,dlscrc);
            } else if (curseglen==padlen-7) {
                dlscrc = ~dlscrc;
                fprintf(stderr,"crc=%x ~crc=%x\n",~dlscrc,dlscrc);
            }
            dlsdg[i][0]=0x00;

            fprintf(stderr,"First Data group: ");
            for (j=0;j<padlen;j++) fprintf(stderr,"%x ",dlsdg[i][j]);
            fprintf(stderr,"\n");

            // SECOND DG (NO CI, NO PREFIX)
            i++;

            dlsdg[i]=(UCHAR*) malloc(padlen*sizeof(UCHAR));
            dlsdg[i][padlen-1]=0x00;                                // FF-PAD Byte L (CI=0)
            dlsdg[i][padlen-2]=0x20;                                // FF-PAD Byte L-1 (Variable size X_PAD)
            if (curseglen==padlen-8) {
                dlsdg[i][padlen-3] = dlscrc & 0x00FF;          // LO CRC
            } else if (curseglen==padlen-7) {
                dlsdg[i][padlen-3] = (dlscrc & 0xFF00) >> 8;     // HI CRC
                dlsdg[i][padlen-4] = dlscrc & 0x00FF;          // LO CRC
            } else {
                for (j=0;j < curseglen-k; j++) {                                // DLS text
                    dlsdg[i][padlen-3-j]=curseg[k+j];
                    dlscrc = update_crc_ccitt(dlscrc, dlsdg[i][padlen-3-j]);
                }
                dlscrc = ~dlscrc;
                dlsdg[i][padlen-3-curseglen+k]=(dlscrc & 0xFF00) >> 8;     // HI CRC
                dlsdg[i][padlen-3-curseglen+k-1]=dlscrc & 0x00FF;          // LO CRC
            }

            fprintf(stderr,"Second Data group: ");
            for (j=0;j<padlen;j++) fprintf(stderr,"%x ",dlsdg[i][j]);
            fprintf(stderr,"\n");
            fprintf(stderr,"**** crc=%x ~crc=%x\n",~dlscrc,dlscrc);
            i++;
        }

    }
}