filter.c

Example use of compression filters.

#include "tools.h"
 
void print_filter_help() {
    printf("Usage: filter -f [flate|dct|jpx|ascii85|ascii_hex] [encode|decode] -s [source file] -d [destination file]");
}
 
int process_filter(int argc, char *argv[]) {
 
    InputStreamHandle* input_stream = NULL;
    OutputStreamHandle* output_stream = NULL;
 
    BufferHandle* input_data = NULL;
 
    int arg_counter = 0;
    const char *filter_type = NULL;
    const char *operation = NULL;
    const char *source_file = NULL;
    const char *destination_file = NULL;
 
    boolean_type is_encode = VANILLAPDF_RV_FALSE;
    boolean_type is_decode = VANILLAPDF_RV_FALSE;
 
    boolean_type is_flate_decode = VANILLAPDF_RV_FALSE;
    boolean_type is_dct_decode = VANILLAPDF_RV_FALSE;
    boolean_type is_jpx_decode = VANILLAPDF_RV_FALSE;
    boolean_type is_ascii85_decode = VANILLAPDF_RV_FALSE;
    boolean_type is_ascii_hex_decode = VANILLAPDF_RV_FALSE;
 
    for (arg_counter = 0; arg_counter < argc; ++arg_counter) {
 
        // filter type
        if (strcmp(argv[arg_counter], "-f") == 0 && (arg_counter + 2 < argc)) {
            filter_type = argv[arg_counter + 1];
            operation = argv[arg_counter + 2];
            arg_counter++;
            arg_counter++;
 
        // source file
        } else if (strcmp(argv[arg_counter], "-s") == 0 && (arg_counter + 1 < argc)) {
            source_file = argv[arg_counter + 1];
            arg_counter++;
 
        // destination file
        } else if (strcmp(argv[arg_counter], "-d") == 0 && (arg_counter + 1 < argc)) {
            destination_file = argv[arg_counter + 1];
            arg_counter++;
        } else {
            print_filter_help();
            return VANILLAPDF_TOOLS_ERROR_INVALID_PARAMETERS;
        }
    }
 
    if (filter_type == NULL || operation == NULL || source_file == NULL || destination_file == NULL) {
        print_filter_help();
        return VANILLAPDF_TOOLS_ERROR_INVALID_PARAMETERS;
    }
 
    is_encode = (strcmp(operation, "encode") == 0);
    is_decode = (strcmp(operation, "decode") == 0);
 
    if (!is_encode && !is_decode) {
        print_filter_help();
        return VANILLAPDF_TOOLS_ERROR_INVALID_PARAMETERS;
    }
 
    is_flate_decode = (strcmp(filter_type, "flate") == 0);
    is_dct_decode = (strcmp(filter_type, "dct") == 0);
    is_jpx_decode = (strcmp(filter_type, "jpx") == 0);
    is_ascii85_decode = (strcmp(filter_type, "ascii85") == 0);
    is_ascii_hex_decode = (strcmp(filter_type, "ascii_hex") == 0);
 
    if (!is_flate_decode &&
        !is_dct_decode &&
        !is_jpx_decode &&
        !is_ascii85_decode &&
        !is_ascii_hex_decode) {
        print_filter_help();
        return VANILLAPDF_TOOLS_ERROR_INVALID_PARAMETERS;
    }
 
    RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_CreateFromFile(destination_file, &output_stream));
 
    RETURN_ERROR_IF_NOT_SUCCESS(InputStream_CreateFromFile(source_file, &input_stream));
    RETURN_ERROR_IF_NOT_SUCCESS(InputStream_ToBuffer(input_stream, &input_data));
 
    if (is_flate_decode) {
        FlateDecodeFilterHandle* filter_handle = NULL;
        RETURN_ERROR_IF_NOT_SUCCESS(FlateDecodeFilter_Create(&filter_handle));
 
        if (is_encode) {
            BufferHandle* encoded_data = NULL;
 
            RETURN_ERROR_IF_NOT_SUCCESS(FlateDecodeFilter_Encode(filter_handle, input_data, &encoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, encoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(encoded_data));
        }
 
        if (is_decode) {
            BufferHandle* decoded_data = NULL;
 
            RETURN_ERROR_IF_NOT_SUCCESS(FlateDecodeFilter_Decode(filter_handle, input_data, &decoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, decoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(decoded_data));
        }
 
        RETURN_ERROR_IF_NOT_SUCCESS(FlateDecodeFilter_Release(filter_handle));
    }
 
    if (is_dct_decode) {
        DCTDecodeFilterHandle* filter_handle = NULL;
        RETURN_ERROR_IF_NOT_SUCCESS(DCTDecodeFilter_Create(&filter_handle));
 
        if (is_encode) {
            BufferHandle* encoded_data = NULL;
 
            RETURN_ERROR_IF_NOT_SUCCESS(DCTDecodeFilter_Encode(filter_handle, input_data, &encoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, encoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(encoded_data));
        }
 
        if (is_decode) {
            BufferHandle* decoded_data = NULL;
 
            RETURN_ERROR_IF_NOT_SUCCESS(DCTDecodeFilter_Decode(filter_handle, input_data, &decoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, decoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(decoded_data));
        }
 
        RETURN_ERROR_IF_NOT_SUCCESS(DCTDecodeFilter_Release(filter_handle));
    }
 
    if (is_jpx_decode) {
        JPXDecodeFilterHandle* filter_handle = NULL;
        RETURN_ERROR_IF_NOT_SUCCESS(JPXDecodeFilter_Create(&filter_handle));
 
        if (is_encode) {
            BufferHandle* encoded_data = NULL;
 
            RETURN_ERROR_IF_NOT_SUCCESS(JPXDecodeFilter_Encode(filter_handle, input_data, &encoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, encoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(encoded_data));
        }
 
        if (is_decode) {
            BufferHandle* decoded_data = NULL;
 
            RETURN_ERROR_IF_NOT_SUCCESS(JPXDecodeFilter_Decode(filter_handle, input_data, &decoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_WriteBuffer(output_stream, decoded_data));
            RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(decoded_data));
        }
 
        RETURN_ERROR_IF_NOT_SUCCESS(JPXDecodeFilter_Release(filter_handle));
    }
 
    RETURN_ERROR_IF_NOT_SUCCESS(OutputStream_Release(output_stream));
    RETURN_ERROR_IF_NOT_SUCCESS(InputStream_Release(input_stream));
    RETURN_ERROR_IF_NOT_SUCCESS(Buffer_Release(input_data));
 
    return VANILLAPDF_TOOLS_ERROR_SUCCESS;
}