implement rtng box

[bradh]

This is from 3GPP TS 26.244 or ETSI TS 126 244 Table 8.7

Resolves #118

[coderabbitai]

Walkthrough

Adds support for a new Rtng atom type. Introduces a public Rtng struct with fields entity, criteria, language, and rating_info, plus AtomExt encode/decode implementations and unit tests. Exposes a new rtng module and pub use rtng::*;. Adds Any::Rtng variant to the generated Any enum. Extends Udta with pub rtng: Option<Rtng> and updates nested optional list and tests accordingly.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The PR title 'implement rtng box' directly and clearly describes the main change: implementing the rtng box as a new atom variant.
Description check	✅ Passed	The PR description references the relevant specification (3GPP TS 26.244 / ETSI TS 126 244 Table 8.7) and links to the resolved issue #118, which is directly related to the rtng box implementation.
Linked Issues check	✅ Passed	The code changes fully implement the rtng box as specified in ETSI TS 126 244 Table 8.7 by adding the Rtng struct with required fields (entity, criteria, language, rating_info) and encoding/decoding support.
Out of Scope Changes check	✅ Passed	All changes are within scope: new Rtng enum variant in Any, Rtng module/struct in udta, optional field in Udta, and encode/decode implementations directly implement the rtng box specification.

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✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@src/moov/udta/rtng.rs`:
- Around line 61-68: Test formatting for the Rtng assert fails rustfmt — run
rustfmt (cargo fmt) and update the formatting around the assert_eq! comparing
the Rtng struct so it matches rustfmt's expected layout (ensure proper
indentation, trailing commas, and alignment for the Rtng { entity, criteria,
language, rating_info } literal used in the assert_eq!); target the Rtng struct
literal and the assert_eq! invocation to normalize spacing/line breaks.

🧹 Nitpick comments (1)

src/moov/udta/rtng.rs (1)

38-43: Validate language codes to avoid silent truncation.
language_code(&self.language) only uses the first three UTF-16 code units; longer strings will be truncated. If the spec requires ISO‑639 3‑letter codes, please validate length/charset and return an error for invalid inputs.

[coderabbitai]

Actionable comments posted: 1

🤖 Fix all issues with AI agents

In `@src/moov/udta/rtng.rs`:
- Around line 12-45: The rtng atom is a FullBox and must read/write the 4-byte
FullBox header (8-bit version + 24-bit flags) before the
entity/criteria/language; update decode_body_ext and encode_body_ext on Rtng to
consume/emit those bytes. In decode_body_ext call u8::decode to read the version
and then read the 3 flag bytes (or decode a u32 and mask off the low 24 bits)
before decoding entity/criteria/language, validating or ignoring the values
(spec expects 0). In encode_body_ext write a zero version byte and zero 24-bit
flags (emit 4 zero bytes) before encoding self.entity, self.criteria, language
code, and rating_info so the FullBox header is present.