konoplayer/packages/matroska/src/systems/seek.ts

64 lines
2.0 KiB
TypeScript

import type {EbmlSeekHeadTagType, EbmlTagType} from "konoebml";
import {SeekHeadSchema, type SeekHeadType} from "../schema";
import {isEqual} from "lodash-es";
import {UnreachableOrLogicError} from "@konoplayer/core/errors";
import {SegmentComponentSystemTrait} from "./segment-component";
export const SEEK_ID_KAX_INFO = new Uint8Array([0x15, 0x49, 0xa9, 0x66]);
export const SEEK_ID_KAX_TRACKS = new Uint8Array([0x16, 0x54, 0xae, 0x6b]);
export const SEEK_ID_KAX_CUES = new Uint8Array([0x1c, 0x53, 0xbb, 0x6b]);
export const SEEK_ID_KAX_TAGS = new Uint8Array([0x12, 0x54, 0xc3, 0x67]);
export class SeekSystem extends SegmentComponentSystemTrait<
EbmlSeekHeadTagType,
typeof SeekHeadSchema
> {
override get schema() {
return SeekHeadSchema;
}
seekHeads: SeekHeadType[] = [];
private offsetToTagMemo: Map<number, EbmlTagType> = new Map();
memoOffset(tag: EbmlTagType) {
this.offsetToTagMemo.set(tag.startOffset, tag);
}
addSeekHeadTag(tag: EbmlSeekHeadTagType) {
const seekHead = this.componentFromTag(tag);
this.seekHeads.push(seekHead);
return seekHead;
}
offsetFromSeekPosition(position: number): number {
return position + this.segment.contentStartOffset;
}
seekTagByStartOffset(
startOffset: number | undefined
): EbmlTagType | undefined {
return startOffset! >= 0
? this.offsetToTagMemo.get(startOffset!)
: undefined;
}
seekOffsetBySeekId(seekId: Uint8Array): number | undefined {
const seekPosition = this.seekHeads[0]?.Seek?.find((c) =>
isEqual(c.SeekID, seekId)
)?.SeekPosition;
return seekPosition! >= 0
? this.offsetFromSeekPosition(seekPosition! as number)
: undefined;
}
seekTagBySeekId(seekId: Uint8Array): EbmlTagType | undefined {
return this.seekTagByStartOffset(this.seekOffsetBySeekId(seekId));
}
get firstClusterOffset() {
if (!this.segment.firstCluster) {
throw new UnreachableOrLogicError('first cluster not found');
}
return this.segment.firstCluster.startOffset;
}
}