livekit/pkg/sfu/utils/helpers.go

// Copyright 2023 LiveKit, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package utils

import (
	"strings"

	"github.com/pion/interceptor"
	"github.com/pion/webrtc/v3"
)

// Do a fuzzy find for a codec in the list of codecs
// Used for lookup up a codec in an existing list to find a match
func CodecParametersFuzzySearch(needle webrtc.RTPCodecParameters, haystack []webrtc.RTPCodecParameters) (webrtc.RTPCodecParameters, error) {
	// First attempt to match on MimeType + SDPFmtpLine
	for _, c := range haystack {
		if strings.EqualFold(c.RTPCodecCapability.MimeType, needle.RTPCodecCapability.MimeType) &&
			c.RTPCodecCapability.SDPFmtpLine == needle.RTPCodecCapability.SDPFmtpLine {
			return c, nil
		}
	}

	// Fallback to just MimeType
	for _, c := range haystack {
		if strings.EqualFold(c.RTPCodecCapability.MimeType, needle.RTPCodecCapability.MimeType) {
			return c, nil
		}
	}

	return webrtc.RTPCodecParameters{}, webrtc.ErrCodecNotFound
}

// GetHeaderExtensionID returns the ID of a header extension, or 0 if not found
func GetHeaderExtensionID(extensions []interceptor.RTPHeaderExtension, extension webrtc.RTPHeaderExtensionCapability) int {
	for _, h := range extensions {
		if extension.URI == h.URI {
			return h.ID
		}
	}
	return 0
}