fn read_ipco()

in mp4parse/src/lib.rs [3597:3649]
46 lines of code
3 McCabe index (conditional complexity)

fn read_ipco<T: Read>(
    src: &mut BMFFBox<T>,
    strictness: ParseStrictness,
) -> Result<TryHashMap<PropertyIndex, ItemProperty>> {
    let mut properties = TryHashMap::with_capacity(ItemPropertiesBox::MIN_PROPERTIES)?;

    let mut index = PropertyIndex(1); // ipma uses 1-based indexing
    let mut iter = src.box_iter();
    while let Some(mut b) = iter.next_box()? {
        let property = match b.head.name {
            BoxType::AuxiliaryTypeProperty => ItemProperty::AuxiliaryType(read_auxc(&mut b)?),
            BoxType::AV1CodecConfigurationBox => ItemProperty::AV1Config(read_av1c(&mut b)?),
            BoxType::ColourInformationBox => ItemProperty::Colour(read_colr(&mut b, strictness)?),
            BoxType::ImageMirror => ItemProperty::Mirroring(read_imir(&mut b)?),
            BoxType::ImageRotation => ItemProperty::Rotation(read_irot(&mut b)?),
            BoxType::ImageSpatialExtentsProperty => {
                ItemProperty::ImageSpatialExtents(read_ispe(&mut b)?)
            }
            BoxType::PixelAspectRatioBox => ItemProperty::PixelAspectRatio(read_pasp(&mut b)?),
            BoxType::PixelInformationBox => ItemProperty::Channels(read_pixi(&mut b)?),

            other_box_type => {
                // Even if we didn't do anything with other property types, we still store
                // a record at the index to identify invalid indices in ipma boxes
                skip_box_remain(&mut b)?;
                let item_property = match other_box_type {
                    BoxType::AV1LayeredImageIndexingProperty => ItemProperty::LayeredImageIndexing,
                    BoxType::CleanApertureBox => ItemProperty::CleanAperture,
                    BoxType::LayerSelectorProperty => ItemProperty::LayerSelection,
                    BoxType::OperatingPointSelectorProperty => ItemProperty::OperatingPointSelector,
                    _ => {
                        warn!("No ItemProperty variant for {:?}", other_box_type);
                        ItemProperty::Unsupported(other_box_type)
                    }
                };
                debug!("Storing empty record {:?}", item_property);
                item_property
            }
        };
        properties.insert(index, property)?;

        index = PropertyIndex(
            index
                .0
                .checked_add(1) // must include ignored properties to have correct indexes
                .ok_or_else(|| Error::from(Status::IpcoIndexOverflow))?,
        );

        check_parser_state!(b.content);
    }

    Ok(properties)
}