To compile the multimedia submodule for a compilation unit, which contains _external_file, _figure and _sound packages.

§1. Everything is done here: 

void RTMultimedia::compile_files(void) {
    files_data *exf;
    LOOP_OVER(exf, files_data) {
        text_stream *desc = Str::new();
        WRITE_TO(desc, "external file '%W'", exf->name);
        Sequence::queue(&RTMultimedia::compilation_agent,
            STORE_POINTER_files_data(exf), desc);
    }
}

void RTMultimedia::compile_internal_files(void) {
    internal_files_data *inf;
    LOOP_OVER(inf, internal_files_data) {
        text_stream *desc = Str::new();
        WRITE_TO(desc, "internal file '%W'", inf->name);
        Sequence::queue(&RTMultimedia::internal_compilation_agent,
            STORE_POINTER_internal_files_data(inf), desc);
    }
}

void RTMultimedia::compile_figures(void) {
    figures_data *bf;
    LOOP_OVER(bf, figures_data) {
        package_request *pack = RTInstances::package(bf->as_instance);
        Hierarchy::apply_metadata_from_number(pack, INSTANCE_FIGURE_ID_MD_HL,
            (inter_ti) bf->figure_number);
        Hierarchy::apply_metadata_from_filename(pack, INSTANCE_FIGURE_FILENAME_MD_HL,
            bf->filename_of_image_file);
    }
}

void RTMultimedia::compile_sounds(void) {
    sounds_data *bs;
    LOOP_OVER(bs, sounds_data) {
        package_request *pack = RTInstances::package(bs->as_instance);
        Hierarchy::apply_metadata_from_number(pack, INSTANCE_SOUND_ID_MD_HL,
            (inter_ti) bs->sound_number);
        Hierarchy::apply_metadata_from_filename(pack, INSTANCE_SOUND_FILENAME_MD_HL,
            bs->filename_of_sound_file);
    }
}

§2. Files are made with the following agent, which makes a single _external_file package: 

void RTMultimedia::compilation_agent(compilation_subtask *t) {
    files_data *exf = RETRIEVE_POINTER_files_data(t->data);
    wording W = exf->name;
    package_request *P = Hierarchy::local_package_to(EXTERNAL_FILES_HAP, exf->where_created);
    inter_name *exf_iname = Hierarchy::make_iname_with_memo(FILE_HL, P, W);
    inter_name *IFID_array_iname = NULL;
    if (exf->file_ownership == OWNED_BY_SPECIFIC_PROJECT) Make an ownership record2.1;
    Make the file metadata array2.2;
    Make the value metadata2.3;
}

§2.1. Make an ownership record2.1 = 

    IFID_array_iname = Hierarchy::make_iname_with_memo(IFID_HL, P, W);
    packaging_state save =
        EmitArrays::begin_byte(IFID_array_iname, K_value);
    TEMPORARY_TEXT(II)
    WRITE_TO(II, "//%S", exf->IFID_of_owner);
    LOOP_THROUGH_TEXT(pos, II)
        EmitArrays::numeric_entry((inter_ti) Str::get(pos));
    DISCARD_TEXT(II)
    EmitArrays::end(save);

§2.2. Make the file metadata array2.2 = 

    packaging_state save = EmitArrays::begin_word(exf_iname, K_value);
    EmitArrays::iname_entry(Hierarchy::find(AUXF_MAGIC_VALUE_HL));
    EmitArrays::iname_entry(Hierarchy::find(AUXF_STATUS_IS_CLOSED_HL));
    if (exf->file_is_binary) EmitArrays::numeric_entry(EXTERNAL_BINARY_FILE_NFSMF);
    else EmitArrays::numeric_entry(EXTERNAL_TEXT_FILE_NFSMF);
    EmitArrays::numeric_entry(0);
    TEMPORARY_TEXT(WW)
    WRITE_TO(WW, "%w", Lexer::word_raw_text(exf->unextended_filename));
    Str::delete_first_character(WW);
    Str::delete_last_character(WW);
    EmitArrays::text_entry(WW);
    DISCARD_TEXT(WW)
    switch (exf->file_ownership) {
        case OWNED_BY_THIS_PROJECT:
            EmitArrays::iname_entry(RTBibliographicData::IFID_iname()); break;
        case OWNED_BY_ANOTHER_PROJECT:
            EmitArrays::null_entry(); break;
        case OWNED_BY_SPECIFIC_PROJECT:
            EmitArrays::iname_entry(IFID_array_iname); break;
    }
    EmitArrays::end(save);

§2.3. Make the value metadata2.3 = 

    package_request *pack = RTInstances::package(exf->as_instance);
    Hierarchy::apply_metadata_from_iname(pack, INSTANCE_FILE_VALUE_MD_HL, exf_iname);
    Hierarchy::apply_metadata_from_raw_wording(pack, INSTANCE_LEAFNAME_MD_HL,
        Wordings::one_word(exf->unextended_filename));
    Hierarchy::apply_metadata_from_number(pack, INSTANCE_FILE_IS_BINARY_MD_HL,
        (inter_ti) exf->file_is_binary);
    switch (exf->file_ownership) {
        case OWNED_BY_THIS_PROJECT:
            Hierarchy::apply_metadata_from_number(pack, INSTANCE_FILE_OWNED_MD_HL, 1);
            break;
        case OWNED_BY_ANOTHER_PROJECT:
            Hierarchy::apply_metadata_from_number(pack, INSTANCE_FILE_OWNED_BY_OTHER_MD_HL, 1);
            break;
        case OWNED_BY_SPECIFIC_PROJECT:
            Hierarchy::apply_metadata(pack, INSTANCE_FILE_OWNER_MD_HL, exf->IFID_of_owner);
            break;
    }

§3. Internal files are simpler: 

void RTMultimedia::internal_compilation_agent(compilation_subtask *t) {
    internal_files_data *inf = RETRIEVE_POINTER_internal_files_data(t->data);
    wording W = inf->name;
    package_request *P = Hierarchy::local_package_to(INTERNAL_FILES_HAP, inf->where_created);
    inter_name *inf_iname = Hierarchy::make_iname_with_memo(INTERNAL_FILE_HL, P, W);
    Make the internal value metadata3.1;
    Make the internal file metadata array3.2;
}

§3.1. Make the internal value metadata3.1 = 

    package_request *pack = RTInstances::package(inf->as_instance);
    Hierarchy::apply_metadata_from_iname(pack, INSTANCE_FILE_VALUE_MD_HL, inf_iname);
    Hierarchy::apply_metadata_from_filename(pack, INSTANCE_LEAFNAME_MD_HL,
        inf->local_filename);
    Hierarchy::apply_metadata_from_number(pack, INSTANCE_INTERNAL_FILE_FORMAT_MD_HL,
        (inter_ti) inf->file_format);
    Hierarchy::apply_metadata_from_number(pack, INSTANCE_INTERNAL_FILE_ID_MD_HL,
        (inter_ti) inf->resource_id);

§3.2. Make the internal file metadata array3.2 = 

    packaging_state save = EmitArrays::begin_word(inf_iname, K_value);
    EmitArrays::iname_entry(Hierarchy::find(AUXF_MAGIC_VALUE_HL));
    EmitArrays::iname_entry(Hierarchy::find(AUXF_STATUS_IS_CLOSED_HL));
    EmitArrays::numeric_entry((inter_ti) inf->file_format);
    EmitArrays::numeric_entry(0);
    EmitArrays::text_entry(Filenames::get_leafname(inf->local_filename));
    EmitArrays::iname_entry(RTBibliographicData::IFID_iname());
    EmitArrays::numeric_entry((inter_ti) inf->resource_id);
    EmitArrays::end(save);