/**
 * Extracts the mid from the transceiver or the SDP.
 *
 * @param transceiver the transceiver.
 * @param transceiverInitIndex the index of the transceiver in the transceiver's init array.
 * @param sdp the SDP.
 */
export declare const extractMid: (transceiver: RTCRtpTransceiver, transceiverInitIndex: number, sdp: string | undefined) => string;
/**
 * Sets the start bitrate for the VP9, H264, and AV1 codecs in the SDP.
 *
 * @param offerSdp the offer SDP to modify.
 * @param maxBitrateKbps the maximum bitrate in kbps.
 * @param startBitrateFactor the factor (0-1) to multiply with maxBitrateKbps to get the start bitrate.
 * @param targetMid the media ID to target.
 */
export declare const setStartBitrate: (offerSdp: string, maxBitrateKbps: number, startBitrateFactor: number, targetMid: string) => string;
/**
 * Enables stereo in the answer SDP based on the offered stereo in the offer SDP.
 *
 * @param offerSdp the offer SDP containing the stereo configuration.
 * @param answerSdp the answer SDP to be modified.
 */
export declare const enableStereo: (offerSdp: string, answerSdp: string) => string;
/**
 * Removes all codecs from the SDP except the specified codec.
 *
 * @param sdp the SDP to modify.
 * @param codecMimeTypeToKeep the codec mime type to keep (video/h264 or audio/opus).
 * @param fmtpProfileToKeep the fmtp profile to keep (e.g. 'profile-level-id=42e01f' or multiple segments like 'profile-level-id=64001f;packetization-mode=1').
 */
export declare const removeCodecsExcept: (sdp: string, codecMimeTypeToKeep: string, fmtpProfileToKeep: string | undefined) => string;