mirror of
https://github.com/arcodange-org/mediabunny.git
synced 2026-09-30 04:13:51 +02:00
Add new slice-based reader system, port all demuxers to new reader system, add optimized BlobSource
This commit is contained in:
Vanilagy
+50
-100
@@ -6,7 +6,7 @@
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* file, You can obtain one at https://mozilla.org/MPL/2.0/.
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*/
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import { Reader } from '../reader';
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import { FileSlice, readI64Le, readU32Le, readU8 } from '../reader2';
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import { OGGS } from './ogg-misc';
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export const MIN_PAGE_HEADER_SIZE = 27;
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@@ -26,118 +26,68 @@ export type Page = {
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lacingValues: Uint8Array;
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};
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export class OggReader {
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pos = 0;
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constructor(public reader: Reader) {}
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export const readPageHeader = (slice: FileSlice): Page | null => {
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const startPos = slice.filePos;
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readBytes(length: number) {
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const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + length);
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this.pos += length;
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return new Uint8Array(view.buffer, offset, length);
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const capturePattern = readU32Le(slice);
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if (capturePattern !== OGGS) {
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return null;
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}
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readU8() {
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const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + 1);
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this.pos += 1;
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slice.skip(1); // Version
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const headerType = readU8(slice);
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const granulePosition = readI64Le(slice);
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const serialNumber = readU32Le(slice);
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const sequenceNumber = readU32Le(slice);
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const checksum = readU32Le(slice);
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return view.getUint8(offset);
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const numberPageSegments = readU8(slice);
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const lacingValues = new Uint8Array(numberPageSegments);
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for (let i = 0; i < numberPageSegments; i++) {
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lacingValues[i] = readU8(slice);
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}
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readU32() {
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const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + 4);
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this.pos += 4;
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const headerSize = 27 + numberPageSegments;
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const dataSize = lacingValues.reduce((a, b) => a + b, 0);
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const totalSize = headerSize + dataSize;
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return view.getUint32(offset, true);
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}
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return {
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headerStartPos: startPos,
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totalSize,
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dataStartPos: startPos + headerSize,
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dataSize,
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headerType,
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granulePosition,
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serialNumber,
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sequenceNumber,
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checksum,
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lacingValues,
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};
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};
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readI32() {
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const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + 4);
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this.pos += 4;
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export const findNextPageHeader = (slice: FileSlice, until: number) => {
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while (slice.filePos < until - (4 - 1)) { // Size of word minus 1
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const word = readU32Le(slice);
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const firstByte = word & 0xff;
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const secondByte = (word >>> 8) & 0xff;
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const thirdByte = (word >>> 16) & 0xff;
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const fourthByte = (word >>> 24) & 0xff;
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return view.getInt32(offset, true);
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}
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readI64() {
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const low = this.readU32();
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const high = this.readI32();
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return high * 0x100000000 + low;
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}
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readAscii(length: number) {
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const { view, offset } = this.reader.getViewAndOffset(this.pos, this.pos + length);
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this.pos += length;
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let str = '';
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for (let i = 0; i < length; i++) {
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str += String.fromCharCode(view.getUint8(offset + i));
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}
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return str;
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}
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readPageHeader(): Page | null {
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const startPos = this.pos;
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const capturePattern = this.readU32();
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if (capturePattern !== OGGS) {
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return null;
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const O = 0x4f; // 'O'
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if (firstByte !== O && secondByte !== O && thirdByte !== O && fourthByte !== O) {
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continue;
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}
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this.pos += 1; // Version
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const headerType = this.readU8();
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const granulePosition = this.readI64();
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const serialNumber = this.readU32();
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const sequenceNumber = this.readU32();
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const checksum = this.readU32();
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slice.skip(-4);
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const numberPageSegments = this.readU8();
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const lacingValues = new Uint8Array(numberPageSegments);
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for (let i = 0; i < numberPageSegments; i++) {
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lacingValues[i] = this.readU8();
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if (word === OGGS) {
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// We have found the capture pattern
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return true;
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}
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const headerSize = 27 + numberPageSegments;
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const dataSize = lacingValues.reduce((a, b) => a + b, 0);
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const totalSize = headerSize + dataSize;
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return {
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headerStartPos: startPos,
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totalSize,
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dataStartPos: startPos + headerSize,
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dataSize,
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headerType,
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granulePosition,
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serialNumber,
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sequenceNumber,
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checksum,
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lacingValues,
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};
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slice.skip(1);
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}
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findNextPageHeader(until: number) {
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while (this.pos < until - (4 - 1)) { // Size of word minus 1
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const word = this.readU32();
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const firstByte = word & 0xff;
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const secondByte = (word >>> 8) & 0xff;
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const thirdByte = (word >>> 16) & 0xff;
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const fourthByte = (word >>> 24) & 0xff;
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const O = 0x4f; // 'O'
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if (firstByte !== O && secondByte !== O && thirdByte !== O && fourthByte !== O) {
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continue;
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}
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this.pos -= 4;
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if (word === OGGS) {
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// We have found the capture pattern
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return true;
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}
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this.pos += 1;
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}
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return false;
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}
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}
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return false;
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};
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