Adolfo Reyna
58 lines
2.0 KiB
JavaScript
58 lines
2.0 KiB
JavaScript
"use strict";
|
|
Object.defineProperty(exports, "__esModule", { value: true });
|
|
exports.getSamplePositions = void 0;
|
|
const getSamplePositions = ({ stcoBox, stszBox, stscBox, stssBox, sttsBox, cttsBox, }) => {
|
|
var _a;
|
|
const sttsDeltas = [];
|
|
for (const distribution of sttsBox.sampleDistribution) {
|
|
for (let i = 0; i < distribution.sampleCount; i++) {
|
|
sttsDeltas.push(distribution.sampleDelta);
|
|
}
|
|
}
|
|
const cttsEntries = [];
|
|
for (const entry of (_a = cttsBox === null || cttsBox === void 0 ? void 0 : cttsBox.entries) !== null && _a !== void 0 ? _a : [
|
|
{ sampleCount: sttsDeltas.length, sampleOffset: 0 },
|
|
]) {
|
|
for (let i = 0; i < entry.sampleCount; i++) {
|
|
cttsEntries.push(entry.sampleOffset);
|
|
}
|
|
}
|
|
let dts = 0;
|
|
const chunks = stcoBox.entries;
|
|
const samples = [];
|
|
let samplesPerChunk = 1;
|
|
for (let i = 0; i < chunks.length; i++) {
|
|
const hasEntry = stscBox.entries.get(i + 1);
|
|
if (hasEntry !== undefined) {
|
|
samplesPerChunk = hasEntry;
|
|
}
|
|
let offsetInThisChunk = 0;
|
|
for (let j = 0; j < samplesPerChunk; j++) {
|
|
const size = stszBox.countType === 'fixed'
|
|
? stszBox.sampleSize
|
|
: stszBox.entries[samples.length];
|
|
const isKeyframe = stssBox
|
|
? stssBox.sampleNumber.has(samples.length + 1)
|
|
: true;
|
|
const delta = sttsDeltas[samples.length];
|
|
const ctsOffset = cttsEntries[samples.length];
|
|
const cts = dts + ctsOffset;
|
|
samples.push({
|
|
offset: Number(chunks[i]) + offsetInThisChunk,
|
|
size,
|
|
isKeyframe,
|
|
decodingTimestamp: dts,
|
|
timestamp: cts,
|
|
duration: delta,
|
|
chunk: i,
|
|
bigEndian: false,
|
|
chunkSize: null,
|
|
});
|
|
dts += delta;
|
|
offsetInThisChunk += size;
|
|
}
|
|
}
|
|
return samples;
|
|
};
|
|
exports.getSamplePositions = getSamplePositions;
|