fn read_ctts()

in mp4parse/src/lib.rs [4730:4766]

• 29 lines of code
• 3 McCabe index (conditional complexity)

fn read_ctts<T: Read>(src: &mut BMFFBox<T>) -> Result<CompositionOffsetBox> {
    let (version, _) = read_fullbox_extra(src)?;

    let counts = be_u32(src)?;

    if counts
        .checked_mul(8)
        .is_none_or(|bytes| u64::from(bytes) > src.bytes_left())
    {
        return Status::CttsBadSize.into();
    }

    let mut offsets = TryVec::with_capacity(counts.to_usize())?;
    for _ in 0..counts {
        let (sample_count, time_offset) = match version {
            // According to spec, Version0 shoule be used when version == 0;
            // however, some buggy contents have negative value when version == 0.
            // So we always use Version1 here.
            0..=1 => {
                let count = be_u32(src)?;
                let offset = TimeOffsetVersion::Version1(be_i32(src)?);
                (count, offset)
            }
            _ => {
                return Status::CttsBadVersion.into();
            }
        };
        offsets.push(TimeOffset {
            sample_count,
            time_offset,
        })?;
    }

    check_parser_state!(src.content);

    Ok(CompositionOffsetBox { samples: offsets })
}