extract.c

File image extaction full example.

#include "tools.h"

void print_extract_help() {
    printf("Usage: extract -s [source file]");
}

error_type process_stream(StreamObjectHandle* stream, biguint_type object_number, ushort_type generation_number) {
    DictionaryObjectHandle* stream_dictionary = NULL;

    ObjectType type_object_type;
    ObjectType subtype_object_type;

    ObjectHandle* type_object = NULL;
    ObjectHandle* subtype_object = NULL;

    NameObjectHandle* type_name = NULL;
    NameObjectHandle* subtype_name = NULL;

    boolean_type contains_type = VANILLAPDF_RV_FALSE;
    boolean_type contains_subtype = VANILLAPDF_RV_FALSE;
    boolean_type contains_width = VANILLAPDF_RV_FALSE;
    boolean_type contains_height = VANILLAPDF_RV_FALSE;
    boolean_type contains_colorspace = VANILLAPDF_RV_FALSE;

    boolean_type is_type_xobject = VANILLAPDF_RV_FALSE;
    boolean_type is_subtype_image = VANILLAPDF_RV_FALSE;

    boolean_type processed_with_params = VANILLAPDF_RV_FALSE;

    unsigned long long object_number_converted = 0;
    unsigned int generation_number_converted = 0;

    int return_value = 0;
    char output_filename[256] = { 0 };

    RETURN_ERROR_IF_NOT_SUCCESS(StreamObject_GetHeader(stream, &stream_dictionary));

    RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Contains(stream_dictionary, NameConstant_Type, &contains_type));
    RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Contains(stream_dictionary, NameConstant_Subtype, &contains_subtype));

    if (!contains_type || !contains_subtype) {
        goto err;
    }

    RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Find(stream_dictionary, NameConstant_Type, &type_object));
    RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Find(stream_dictionary, NameConstant_Subtype, &subtype_object));

    RETURN_ERROR_IF_NOT_SUCCESS(Object_GetObjectType(type_object, &type_object_type));
    RETURN_ERROR_IF_NOT_SUCCESS(Object_GetObjectType(subtype_object, &subtype_object_type));

    if (type_object_type != ObjectType_Name || subtype_object_type != ObjectType_Name) {
        goto err;
    }

    RETURN_ERROR_IF_NOT_SUCCESS(NameObject_FromObject(type_object, &type_name));
    RETURN_ERROR_IF_NOT_SUCCESS(NameObject_FromObject(subtype_object, &subtype_name));

    RETURN_ERROR_IF_NOT_SUCCESS(NameObject_Equals(type_name, NameConstant_XObject, &is_type_xobject));
    RETURN_ERROR_IF_NOT_SUCCESS(NameObject_Equals(subtype_name, NameConstant_Image, &is_subtype_image));

    if (!is_type_xobject || !is_subtype_image) {
        goto err;
    }

    object_number_converted = object_number;
    generation_number_converted = generation_number;

    return_value = snprintf(output_filename, sizeof(output_filename), "%llu.%u.jpeg", object_number_converted, generation_number_converted);
    if (return_value < 0) {
        printf("Could not create destination filename");
        return VANILLAPDF_TOOLS_ERROR_FAILURE;
    }

    RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Contains(stream_dictionary, NameConstant_Width, &contains_width));
    RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Contains(stream_dictionary, NameConstant_Height, &contains_height));
    RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Contains(stream_dictionary, NameConstant_ColorSpace, &contains_colorspace));

    if (contains_width && contains_height && contains_colorspace) {
        ObjectType width_object_type;
        ObjectType height_object_type;
        ObjectType colorspace_object_type;

        ObjectHandle* width_object = NULL;
        ObjectHandle* height_object = NULL;
        ObjectHandle* colorspace_object = NULL;

        RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Find(stream_dictionary, NameConstant_Width, &width_object));
        RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Find(stream_dictionary, NameConstant_Height, &height_object));
        RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Find(stream_dictionary, NameConstant_ColorSpace, &colorspace_object));

        RETURN_ERROR_IF_NOT_SUCCESS(Object_GetObjectType(width_object, &width_object_type));
        RETURN_ERROR_IF_NOT_SUCCESS(Object_GetObjectType(height_object, &height_object_type));
        RETURN_ERROR_IF_NOT_SUCCESS(Object_GetObjectType(colorspace_object, &colorspace_object_type));

        if (width_object_type == ObjectType_Integer && height_object_type == ObjectType_Integer && colorspace_object_type == ObjectType_Name) {
            OutputStreamHandle* output_stream = NULL;

            DCTDecodeFilterHandle* encoding_filter = NULL;
            DictionaryObjectHandle* encoding_dictionary = NULL;
            BufferHandle* decoded_body = NULL;
            BufferHandle* encoded_body = NULL;

            RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Create(&encoding_dictionary));
            RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_InsertConst(encoding_dictionary, NameConstant_Width, width_object));
            RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_InsertConst(encoding_dictionary, NameConstant_Height, height_object));
            RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_InsertConst(encoding_dictionary, NameConstant_ColorSpace, colorspace_object));

            RETURN_ERROR_IF_NOT_SUCCESS(StreamObject_GetBody(stream, &decoded_body));

            RETURN_ERROR_IF_NOT_SUCCESS(DCTDecodeFilter_Create(&encoding_filter));
            RETURN_ERROR_IF_NOT_SUCCESS(DCTDecodeFilter_EncodeParams(encoding_filter, decoded_body, encoding_dictionary, &encoded_body));
            RETURN_ERROR_IF_NOT_SUCCESS(DCTDecodeFilter_Release(encoding_filter));

            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_CreateFromFile(output_filename, &output_stream));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, encoded_body));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_Flush(output_stream));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_Release(output_stream));

            RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(encoded_body));
            RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(decoded_body));
            RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Release(encoding_dictionary));

            processed_with_params = VANILLAPDF_RV_TRUE;
        }

        RETURN_ERROR_IF_NOT_SUCCESS(Object_Release(width_object));
        RETURN_ERROR_IF_NOT_SUCCESS(Object_Release(height_object));
        RETURN_ERROR_IF_NOT_SUCCESS(Object_Release(colorspace_object));
    }

    if (processed_with_params != VANILLAPDF_RV_TRUE) {
        OutputStreamHandle* output_stream = NULL;
        BufferHandle* encoded_body = NULL;

        RETURN_ERROR_IF_NOT_SUCCESS(StreamObject_GetBodyRaw(stream, &encoded_body));

        RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_CreateFromFile(output_filename, &output_stream));
        RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, encoded_body));
        RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_Flush(output_stream));
        RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_Release(output_stream));

        RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(encoded_body));
    }

err:
    if (type_object != NULL) {
        RETURN_ERROR_IF_NOT_SUCCESS(Object_Release(type_object));
        type_object = NULL;
    }

    if (subtype_object != NULL) {
        RETURN_ERROR_IF_NOT_SUCCESS(Object_Release(subtype_object));
        subtype_object = NULL;
    }

    if (type_name != NULL) {
        RETURN_ERROR_IF_NOT_SUCCESS(NameObject_Release(type_name));
        type_name = NULL;
    }

    if (subtype_name != NULL) {
        RETURN_ERROR_IF_NOT_SUCCESS(NameObject_Release(subtype_name));
        subtype_name = NULL;
    }

    if (stream_dictionary != NULL) {
        RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Release(stream_dictionary));
        stream_dictionary = NULL;
    }

    return VANILLAPDF_TOOLS_ERROR_SUCCESS;
}

error_type process_object(ObjectHandle* obj, biguint_type object_number, ushort_type generation_number) {

    ObjectType type;

    RETURN_ERROR_IF_NOT_SUCCESS(Object_GetObjectType(obj, &type));

    if (type == ObjectType_Stream) {
        StreamObjectHandle* stream = NULL;

        RETURN_ERROR_IF_NOT_SUCCESS(StreamObject_FromObject(obj, &stream));
        RETURN_ERROR_IF_NOT_SUCCESS(process_stream(stream, object_number, generation_number));
        RETURN_ERROR_IF_NOT_SUCCESS(StreamObject_Release(stream));
    }

    return VANILLAPDF_TOOLS_ERROR_SUCCESS;
}

error_type process_xref(XrefHandle* xref) {
    XrefIteratorHandle* xref_iterator = NULL;
    boolean_type valid = VANILLAPDF_RV_FALSE;

    RETURN_ERROR_IF_NOT_SUCCESS(Xref_GetIterator(xref, &xref_iterator));

    while (VANILLAPDF_ERROR_SUCCESS == XrefIterator_IsValid(xref_iterator, &valid)
        && VANILLAPDF_RV_TRUE == valid) {

        XrefEntryType type;
        XrefEntryHandle* entry = NULL;
        XrefCompressedEntryHandle* compressed_entry = NULL;
        XrefUsedEntryHandle* used_entry = NULL;

        biguint_type object_number = 0;
        ushort_type generation_number = 0;

        RETURN_ERROR_IF_NOT_SUCCESS(XrefIterator_GetValue(xref_iterator, &entry));
        RETURN_ERROR_IF_NOT_SUCCESS(XrefEntry_GetType(entry, &type));
        RETURN_ERROR_IF_NOT_SUCCESS(XrefEntry_GetObjectNumber(entry, &object_number));
        RETURN_ERROR_IF_NOT_SUCCESS(XrefEntry_GetGenerationNumber(entry, &generation_number));

        if (type == XrefEntryType_Used) {
            ObjectHandle* obj = NULL;

            RETURN_ERROR_IF_NOT_SUCCESS(XrefUsedEntry_FromEntry(entry, &used_entry));
            RETURN_ERROR_IF_NOT_SUCCESS(XrefUsedEntry_GetReference(used_entry, &obj));
            RETURN_ERROR_IF_NOT_SUCCESS(process_object(obj, object_number, generation_number));
            RETURN_ERROR_IF_NOT_SUCCESS(Object_Release(obj));
            RETURN_ERROR_IF_NOT_SUCCESS(XrefUsedEntry_Release(used_entry));
        }

        if (type == XrefEntryType_Compressed) {
            ObjectHandle* obj = NULL;

            RETURN_ERROR_IF_NOT_SUCCESS(XrefCompressedEntry_FromEntry(entry, &compressed_entry));
            RETURN_ERROR_IF_NOT_SUCCESS(XrefCompressedEntry_GetReference(compressed_entry, &obj));
            RETURN_ERROR_IF_NOT_SUCCESS(process_object(obj, object_number, generation_number));
            RETURN_ERROR_IF_NOT_SUCCESS(Object_Release(obj));
            RETURN_ERROR_IF_NOT_SUCCESS(XrefCompressedEntry_Release(compressed_entry));
        }

        RETURN_ERROR_IF_NOT_SUCCESS(XrefEntry_Release(entry));
        RETURN_ERROR_IF_NOT_SUCCESS(XrefIterator_Next(xref_iterator));
    }

    RETURN_ERROR_IF_NOT_SUCCESS(XrefIterator_Release(xref_iterator));

    return VANILLAPDF_TOOLS_ERROR_SUCCESS;
}

error_type process_file(FileHandle* file) {
    XrefChainHandle* chain = NULL;
    XrefChainIteratorHandle* chain_iterator = NULL;
    boolean_type valid = VANILLAPDF_RV_FALSE;

    RETURN_ERROR_IF_NOT_SUCCESS(File_XrefChain(file, &chain));
    RETURN_ERROR_IF_NOT_SUCCESS(XrefChain_GetIterator(chain, &chain_iterator));

    while (VANILLAPDF_ERROR_SUCCESS == XrefChainIterator_IsValid(chain_iterator, &valid)
        && VANILLAPDF_RV_TRUE == valid) {
        XrefHandle* xref = NULL;

        RETURN_ERROR_IF_NOT_SUCCESS(XrefChainIterator_GetValue(chain_iterator, &xref));
        RETURN_ERROR_IF_NOT_SUCCESS(process_xref(xref));
        RETURN_ERROR_IF_NOT_SUCCESS(Xref_Release(xref));
        RETURN_ERROR_IF_NOT_SUCCESS(XrefChainIterator_Next(chain_iterator));
    }

    RETURN_ERROR_IF_NOT_SUCCESS(XrefChainIterator_Release(chain_iterator));
    RETURN_ERROR_IF_NOT_SUCCESS(XrefChain_Release(chain));

    return VANILLAPDF_TOOLS_ERROR_SUCCESS;
}

error_type process_page_contents(PageContentsHandle* page_contents, size_type page_number) {
    size_type i = 0;
    size_type contents_size = 0;
    unsigned long long page_number_converted = page_number;

    RETURN_ERROR_IF_NOT_SUCCESS(PageContents_GetInstructionsSize(page_contents, &contents_size));

    for (i = 0; i < contents_size; ++i) {
        ContentInstructionType instruction_type;
        ContentObjectType object_type;
        ContentInstructionHandle* content_instruction = NULL;
        ContentObjectHandle* content_object = NULL;
        ContentObjectInlineImageHandle* content_image = NULL;
        DictionaryObjectHandle* content_image_dictionary = NULL;
        BufferHandle* content_image_data = NULL;

        int return_value = 0;
        unsigned long long i_converted = i;
        char output_filename[256] = {0};
        OutputStreamHandle* output_stream = NULL;

        RETURN_ERROR_IF_NOT_SUCCESS(PageContents_GetInstructionAt(page_contents, i, &content_instruction));
        RETURN_ERROR_IF_NOT_SUCCESS(ContentInstruction_GetInstructionType(content_instruction, &instruction_type));

        if (instruction_type != ContentInstructionType_Object) {
            RETURN_ERROR_IF_NOT_SUCCESS(ContentInstruction_Release(content_instruction));
            continue;
        }

        RETURN_ERROR_IF_NOT_SUCCESS(ContentObject_FromInstruction(content_instruction, &content_object));
        RETURN_ERROR_IF_NOT_SUCCESS(ContentObject_GetObjectType(content_object, &object_type));

        if (object_type != ContentObjectType_InlineImage) {
            RETURN_ERROR_IF_NOT_SUCCESS(ContentObject_Release(content_object));
            RETURN_ERROR_IF_NOT_SUCCESS(ContentInstruction_Release(content_instruction));
            continue;
        }

        RETURN_ERROR_IF_NOT_SUCCESS(ContentObject_ToInlineImage(content_object, &content_image));
        RETURN_ERROR_IF_NOT_SUCCESS(ContentObjectInlineImage_GetDictionary(content_image, &content_image_dictionary));
        RETURN_ERROR_IF_NOT_SUCCESS(ContentObjectInlineImage_GetData(content_image, &content_image_data));

        return_value = snprintf(output_filename, sizeof(output_filename), "%llu.%llu", page_number_converted, i_converted);
        if (return_value < 0) {
            printf("Could not create destination filename");
            return VANILLAPDF_TOOLS_ERROR_FAILURE;
        }

        RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_CreateFromFile(output_filename, &output_stream));
        RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, content_image_data));
        RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_Flush(output_stream));
        RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_Release(output_stream));

        RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(content_image_data));
        RETURN_ERROR_IF_NOT_SUCCESS(DictionaryObject_Release(content_image_dictionary));

        RETURN_ERROR_IF_NOT_SUCCESS(ContentObjectInlineImage_Release(content_image));
        RETURN_ERROR_IF_NOT_SUCCESS(ContentObject_Release(content_object));
        RETURN_ERROR_IF_NOT_SUCCESS(ContentInstruction_Release(content_instruction));
    }

    return VANILLAPDF_TOOLS_ERROR_SUCCESS;
}

int process_extract(int argc, char *argv[]) {

    const char *filename = NULL;
    int arg_counter = 0;

    size_type i = 0;
    size_type page_count = 0;

    FileHandle* file = NULL;
    DocumentHandle* document = NULL;
    CatalogHandle* catalog = NULL;
    PageTreeHandle* tree = NULL;

    for (arg_counter = 0; arg_counter < argc; ++arg_counter) {

        // source file
        if (strcmp(argv[arg_counter], "-s") == 0 && (arg_counter + 1 < argc)) {
            filename = argv[arg_counter + 1];
            arg_counter++;
        } else {
            print_extract_help();
            return VANILLAPDF_TOOLS_ERROR_INVALID_PARAMETERS;
        }
    }

    if (filename == NULL) {
        print_extract_help();
        return VANILLAPDF_TOOLS_ERROR_INVALID_PARAMETERS;
    }

    RETURN_ERROR_IF_NOT_SUCCESS(File_Open(filename, &file));
    RETURN_ERROR_IF_NOT_SUCCESS(File_Initialize(file));

    RETURN_ERROR_IF_NOT_SUCCESS(process_file(file));

    RETURN_ERROR_IF_NOT_SUCCESS(Document_OpenFile(file, &document));

    RETURN_ERROR_IF_NOT_SUCCESS(Document_GetCatalog(document, &catalog));
    RETURN_ERROR_IF_NOT_SUCCESS(Catalog_GetPages(catalog, &tree));
    RETURN_ERROR_IF_NOT_SUCCESS(PageTree_GetPageCount(tree, &page_count));

    for (i = 0; i < page_count; ++i) {
        PageContentsHandle* page_contents = NULL;
        PageObjectHandle* page_object = NULL;

        RETURN_ERROR_IF_NOT_SUCCESS(PageTree_GetPage(tree, i + 1, &page_object));
        RETURN_ERROR_IF_NOT_SUCCESS(PageObject_GetContents(page_object, &page_contents));

        RETURN_ERROR_IF_NOT_SUCCESS(process_page_contents(page_contents, i + 1));

        RETURN_ERROR_IF_NOT_SUCCESS(PageContents_Release(page_contents));
        RETURN_ERROR_IF_NOT_SUCCESS(PageObject_Release(page_object));
    }

    RETURN_ERROR_IF_NOT_SUCCESS(PageTree_Release(tree));
    RETURN_ERROR_IF_NOT_SUCCESS(Catalog_Release(catalog));
    RETURN_ERROR_IF_NOT_SUCCESS(Document_Release(document));

    RETURN_ERROR_IF_NOT_SUCCESS(File_Release(file));

    return VANILLAPDF_TOOLS_ERROR_SUCCESS;
}