opc_image.c

Sample program which will extract all images from an OPC container. E.g. opc_dump hello.pptx will extract all pictures from "hello.pptx" in the current directory. The call opc_dump hello.pptx C: will extract all pictures from "hello.pptx" in the directory "C:\Users\flr\Pictures".

/*
    Extract all images from an OPC container.

    Ussage:
    opc_image FILENAME [OUTPATH]

    The OUTPATH must exist.

    Sample:
    opc_image OOXMLI1.docx C:\Users\flr\Pictures
*/

#include <opc/opc.h>
#include <stdio.h>
#include <time.h>
#ifdef WIN32
#include <crtdbg.h>
#endif

static void extract(opcContainer *c, opcPart p, const char *path) {
    char filename[OPC_MAX_PATH];
    opc_uint32_t i=xmlStrlen(p);
    while(i>0 && p[i]!='/') i--;
    if (p[i]=='/') i++;    
    strcpy(filename, path);
    strcat(filename,  (char *)(p+i));    
    FILE *out=fopen(filename, "wb");
    if (NULL!=out) {
        opcContainerInputStream *stream=opcContainerOpenInputStream(c, p);
        if (NULL!=stream) {
            opc_uint32_t  ret=0;
            opc_uint8_t buf[100];
            while((ret=opcContainerReadInputStream(stream, buf, sizeof(buf)))>0) {
                fwrite(buf, sizeof(char), ret, out);
            }
            opcContainerCloseInputStream(stream);
        }
        fclose(out);
    }
}

int main( int argc, const char* argv[] )
{    
#ifdef WIN32
     _CrtSetDbgFlag (_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF);
#endif
    opcInitLibrary();
    opcContainer *c=opcContainerOpen(_X(argv[1]), OPC_OPEN_READ_ONLY, NULL, NULL);
    const char *path=(argc>1?argv[2]:"");
    if (NULL!=c) {
        for(opcPart part=opcPartGetFirst(c);OPC_PART_INVALID!=part;part=opcPartGetNext(c, part)) {
            const xmlChar *type=opcPartGetType(c, part);
            if (xmlStrcmp(type, _X("image/jpeg"))==0) {
                extract(c, part, path);
            } else if (xmlStrcmp(type, _X("image/png"))==0) {
                extract(c, part, path);
            } else {
                printf("skipped %s of type %s\n", part, type);
            }
        }
        opcContainerClose(c, OPC_CLOSE_NOW);
    }
    opcFreeLibrary();
#ifdef WIN32
    OPC_ASSERT(!_CrtDumpMemoryLeaks());
#endif
    return 0;
}