fix!: correctly support wildcard payload types in feedback lines

[bbaldino]

Description

This change adds support for wildcard payload types in feedback lines, e.g.:

a=rtcp-fb:* nack pli
a=rtcp-fb:* ccm msync
a=rtcp-fb:* ccm fir
a=rtcp-fb:* nack

Chrome is starting to use in v147. Currently, these would fail to parse but would fallback to UnknownLine which is fine as long as no manipulation around them is needed.

The design of this fix introduces a new PayloadTypeRef type that models the payload type as a number or *. There are still places, though, where we want a "resolved" payload type (number only), so the naming of this type was chosen to try and distinguish an SDP-syntax "reference" to a payload type, not an actual payload type (for which number is still used).

This change implements...

• A new feature
• A bug fix
• Other (please specify):

Is this a breaking change?

• Yes - The type of the payload type member on some types as changed, as well as some constructor argument types
• No

I certify that...

• All relevant unit and integration tests have passed and/or have been updated according to this change.

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[Copilot]

Pull request overview

This PR adds proper support for wildcard payload type (*) in SDP rtcp-fb lines (e.g., a=rtcp-fb:* nack pli), which Chrome v147+ is starting to emit. Previously these lines would fail to parse and fall back to UnknownLine. The change introduces a PayloadTypeRef type wrapping number | '*' and a new CodecStore class to separate per-codec from wildcard feedback storage.

Changes:

• New PayloadTypeRef class and CodecStore class; RtcpFbLine regex updated to match *; RtpMapLine, FmtpLine, RtcpFbLine constructors updated to accept PayloadTypeRef instead of number.
• AvMediaDescription.codecs changed from Map<number, CodecInfo> to CodecStore; codec-related line routing refactored to use CodecStore.addLine.
• disableRtcpFbValue in munge.ts simplified to delegate to CodecStore.removeFeedback, correctly handling wildcard feedback.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/lines/payload-type-ref.ts	New class modeling a payload type reference as number or '*'
src/lines/payload-type-ref.spec.ts	Tests for the new PayloadTypeRef class
src/lines/rtcpfb-line.ts	Updated regex and parsing to support wildcard *; payloadType field changed to PayloadTypeRef
src/lines/rtcpfb-line.spec.ts	New tests for wildcard and numeric parsing/serialization of RtcpFbLine
src/lines/rtpmap-line.ts	payloadType field changed to PayloadTypeRef; constructor updated
src/lines/fmtp-line.ts	payloadType field changed to PayloadTypeRef; constructor updated
src/lines/index.ts	Exports PayloadTypeRef
src/model/codec-store.ts	New CodecStore class handling per-codec and wildcard feedback
src/model/codec-store.spec.ts	Tests for CodecStore
src/model/codec-info.ts	Uses PayloadTypeRef in toLines()
src/model/av-media-description.ts	Uses CodecStore instead of raw Map<number, CodecInfo>
src/model/index.ts	Exports CodecStore
src/munge.ts	Delegates feedback removal to CodecStore.removeFeedback
src/utils.spec.ts	Uses PayloadTypeRef when constructing RtpMapLine
src/parser.spec.ts	New test for parsing an SDP with wildcard rtcp-fb lines

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[Copilot]

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 1 comment.

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[Copilot]

The toLines() method always emits all per-codec lines first, then wildcard feedback lines at the end. However, in the wildcard_rtcpfb.sdp corpus file (and in real-world Chrome SDPs), wildcard rtcp-fb lines appear before per-codec feedback lines. After a round-trip parse-and-serialize, the ordering changes: a=rtcp-fb:96 ccm fir will appear before a=rtcp-fb:* goog-remb, a=rtcp-fb:* nack, etc.

While the compareSdps test helper ignores ordering so the round-trip test passes, and RFC 4585 doesn't mandate a specific ordering of rtcp-fb lines, this reordering could be a concern for interoperability with SDP consumers that are sensitive to ordering. Consider whether preserving the original relative order of wildcard and per-codec lines is desirable. Note that this is consistent with the codebase's existing behavior of reordering lines during serialization (as documented in src/sdp-corpus/ordering.ts).

[bbaldino]

I think this is probably fine as-is.