@remotion/renderer
Version:
Render Remotion videos using Node.js or Bun
157 lines (156 loc) • 6.33 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.stringifyFfmpegFilter = exports.getActualTrimLeft = void 0;
const calculate_atempo_1 = require("./assets/calculate-atempo");
const ffmpeg_volume_expression_1 = require("./assets/ffmpeg-volume-expression");
const logger_1 = require("./logger");
const sample_rate_1 = require("./sample-rate");
const truthy_1 = require("./truthy");
const cleanUpFloatingPointError = (value) => {
if (value % 1 < 0.0000001) {
return Math.floor(value);
}
if (value % 1 > 0.9999999) {
return Math.ceil(value);
}
return value;
};
const stringifyTrim = (trim) => {
const value = cleanUpFloatingPointError(trim * 1000000);
const asString = `${value}us`;
// Handle very small values such as `"6e-7us"`, those are essentially rounding errors to 0
if (asString.includes('e-')) {
return '0us';
}
return asString;
};
const getActualTrimLeft = ({ asset, fps, trimLeftOffset, seamless, assetDuration, }) => {
const sinceStart = asset.trimLeft - asset.audioStartFrame;
if (!seamless) {
return {
trimLeft: asset.audioStartFrame / fps +
(sinceStart / fps) * asset.playbackRate +
trimLeftOffset,
maxTrim: assetDuration,
};
}
if (seamless) {
return {
trimLeft: asset.audioStartFrame / fps / asset.playbackRate +
sinceStart / fps +
trimLeftOffset,
maxTrim: assetDuration ? assetDuration / asset.playbackRate : null,
};
}
throw new Error('This should never happen');
};
exports.getActualTrimLeft = getActualTrimLeft;
const trimAndSetTempo = ({ assetDuration, asset, trimLeftOffset, trimRightOffset, fps, indent, logLevel, }) => {
// We need to apply the tempo filter first
// because the atempo filter is not frame-perfect.
// It creates a small offset and the offset needs to be the same for all audio tracks, before processing it further.
// This also affects the trimLeft and trimRight values, as they need to be adjusted.
const { trimLeft, maxTrim } = (0, exports.getActualTrimLeft)({
asset,
fps,
trimLeftOffset,
seamless: true,
assetDuration,
});
const trimRight = trimLeft + asset.duration / fps - trimLeftOffset + trimRightOffset;
let trimRightOrAssetDuration = maxTrim
? Math.min(trimRight, maxTrim)
: trimRight;
if (trimRightOrAssetDuration < trimLeft) {
logger_1.Log.warn({ indent, logLevel }, 'trimRightOrAssetDuration < trimLeft: ' +
JSON.stringify({
trimRight,
trimLeft,
assetDuration,
assetTrimLeft: asset.trimLeft,
}));
trimRightOrAssetDuration = trimLeft;
}
return {
filter: [
(0, calculate_atempo_1.calculateATempo)(asset.playbackRate),
`atrim=${stringifyTrim(trimLeft)}:${stringifyTrim(trimRightOrAssetDuration)}`,
],
actualTrimLeft: trimLeft,
audibleDuration: trimRightOrAssetDuration - trimLeft,
};
};
const stringifyFfmpegFilter = ({ channels, volume, fps, assetDuration, chunkLengthInSeconds, forSeamlessAacConcatenation, trimLeftOffset, trimRightOffset, asset, indent, logLevel, presentationTimeOffsetInSeconds, }) => {
if (channels === 0) {
return null;
}
const { toneFrequency, startInVideo } = asset;
const startInVideoSeconds = startInVideo / fps;
const { trimLeft, maxTrim } = (0, exports.getActualTrimLeft)({
asset,
fps,
trimLeftOffset,
seamless: forSeamlessAacConcatenation,
assetDuration,
});
if (maxTrim && trimLeft >= maxTrim) {
return null;
}
if (toneFrequency !== null && (toneFrequency <= 0 || toneFrequency > 2)) {
throw new Error('toneFrequency must be a positive number between 0.01 and 2');
}
const { actualTrimLeft, audibleDuration, filter: trimAndTempoFilter, } = trimAndSetTempo({
assetDuration,
trimLeftOffset,
trimRightOffset,
asset,
fps,
indent,
logLevel,
});
const volumeFilter = (0, ffmpeg_volume_expression_1.ffmpegVolumeExpression)({
volume,
fps,
trimLeft: actualTrimLeft,
});
const padAtEnd = chunkLengthInSeconds - audibleDuration - startInVideoSeconds;
const padStart = startInVideoSeconds +
(asset.trimLeft === 0 ? presentationTimeOffsetInSeconds : 0);
// Set as few filters as possible, as combining them can create noise
return {
filter: `[0:a]` +
[
`aformat=sample_fmts=s32:sample_rates=${sample_rate_1.DEFAULT_SAMPLE_RATE}`,
// The order matters here! For speed and correctness, we first trim the audio
...trimAndTempoFilter,
// The timings for volume must include whatever is in atrim, unless the volume
// filter gets applied before atrim
volumeFilter.value === '1'
? null
: `volume=${volumeFilter.value}:eval=${volumeFilter.eval}`,
toneFrequency && toneFrequency !== 1
? `asetrate=${sample_rate_1.DEFAULT_SAMPLE_RATE}*${toneFrequency},aresample=${sample_rate_1.DEFAULT_SAMPLE_RATE},atempo=1/${toneFrequency}`
: null,
]
.filter(truthy_1.truthy)
.join(',') +
`[a0]`,
pad_end: padAtEnd > 0.0000001
? 'apad=pad_len=' + Math.round(padAtEnd * sample_rate_1.DEFAULT_SAMPLE_RATE)
: null,
pad_start:
// For n channels, we delay n + 1 channels.
// This is because `ffprobe` for some audio files reports the wrong amount
// of channels.
// This should be fine because FFMPEG documentation states:
// "Unused delays will be silently ignored."
// https://ffmpeg.org/ffmpeg-filters.html#adelay
padStart === 0
? null
: `adelay=${new Array(channels + 1)
.fill((padStart * 1000).toFixed(0))
.join('|')}`,
actualTrimLeft,
};
};
exports.stringifyFfmpegFilter = stringifyFfmpegFilter;