/**
 * Ogg/Opus container inspection.
 *
 * Pure functions, zero dependencies — no I/O, no env, no clients. Used to fill
 * the duration field of a voice-note bubble and as a regression check that TTS
 * output stayed mono (some mobile clients refuse stereo voice notes).
 *
 * Inbound audio is attacker-controlled, so this walks the page structure via
 * the segment table rather than scanning for the `OggS` capture pattern. A
 * scan would let those four bytes appearing inside packet payload masquerade
 * as a page header, and the granule read from that offset — arbitrary audio
 * data — would become the reported duration.
 */
export interface OggOpusInfo {
    /** Channel count from the OpusHead identification header. */
    channels: number;
    /** Whole seconds, derived from the final page's granule position. */
    seconds: number;
}
/**
 * Parse channel count and duration from an Ogg/Opus stream.
 *
 * Returns null for anything that is not a readable Ogg/Opus stream — a
 * truncated buffer, a missing or malformed OpusHead, a page whose segment
 * table runs past the end, or a granule we cannot trust (the unknown-position
 * sentinel, or a value implying an implausible duration). Callers treat null
 * as "do not send this as audio".
 */
export declare function parseOggOpus(bytes: Uint8Array): OggOpusInfo | null;
/**
 * Look for container-metadata bleed-through in the comment (OpusTags) header
 * — the second page of a well-formed stream, right after OpusHead.
 *
 * This is a warning-level signal, not a validity check: `parseOggOpus` above
 * never reads this page and its pass/fail contract is unaffected either way.
 * A non-empty result means the encoder that produced this file carried
 * MP4/QuickTime container fields (`major_brand`, `com.android.version`, ...)
 * into the Ogg comment header — usually because a phone recording was
 * transcoded with ffmpeg's default `-map_metadata` instead of `-map_metadata
 * -1`. Some strict players (WhatsApp's Android extractor among them) reject
 * files with this signature even though lenient readers, including ffmpeg
 * itself, decode them fine.
 *
 * Returns `null` when there is no readable comment header to inspect (short
 * buffer, missing OpusTags page, truncated field) — that is "no signal",
 * distinct from an empty array meaning "read cleanly, nothing suspicious".
 */
export declare function findSuspiciousOggComments(bytes: Uint8Array): string[] | null;