import * as ffmpeg from 'fluent-ffmpeg'
import { join } from 'path'
import { VideoResolution } from '../../shared/models/videos'
-import { CONFIG, VIDEO_TRANSCODING_FPS } from '../initializers'
+import { CONFIG, VIDEO_TRANSCODING_FPS, FFMPEG_NICE } from '../initializers'
import { unlinkPromise } from './core-utils'
import { processImage } from './image-utils'
import { logger } from './logger'
+import { checkFFmpegEncoders } from '../initializers/checker'
async function getVideoFileResolution (path: string) {
const videoStream = await getVideoFileStream(path)
try {
await new Promise<string>((res, rej) => {
- ffmpeg(fromPath)
+ ffmpeg(fromPath, { niceness: FFMPEG_NICE.THUMBNAIL })
.on('error', rej)
.on('end', () => res(imageName))
.thumbnail(options)
function transcode (options: TranscodeOptions) {
return new Promise<void>(async (res, rej) => {
- let command = ffmpeg(options.inputPath)
+ let command = ffmpeg(options.inputPath, { niceness: FFMPEG_NICE.TRANSCODING })
.output(options.outputPath)
- .videoCodec('libx264')
- .outputOption('-threads ' + CONFIG.TRANSCODING.THREADS)
- .outputOption('-movflags faststart')
- // .outputOption('-crf 18')
+ .preset(standard)
+
+ if (CONFIG.TRANSCODING.THREADS > 0) {
+ // if we don't set any threads ffmpeg will chose automatically
+ command = command.outputOption('-threads ' + CONFIG.TRANSCODING.THREADS)
+ }
let fps = await getVideoFileFPS(options.inputPath)
if (options.resolution !== undefined) {
getDurationFromVideoFile,
generateImageFromVideoFile,
transcode,
- getVideoFileFPS
+ getVideoFileFPS,
+ audio
}
// ---------------------------------------------------------------------------
})
})
}
+
+/**
+ * A slightly customised version of the 'veryfast' x264 preset
+ *
+ * The veryfast preset is right in the sweet spot of performance
+ * and quality. Superfast and ultrafast will give you better
+ * performance, but then quality is noticeably worse.
+ */
+function veryfast (_ffmpeg) {
+ _ffmpeg
+ .preset(standard)
+ .outputOption('-preset:v veryfast')
+ .outputOption(['--aq-mode=2', '--aq-strength=1.3'])
+ /*
+ MAIN reference: https://slhck.info/video/2017/03/01/rate-control.html
+ Our target situation is closer to a livestream than a stream,
+ since we want to reduce as much a possible the encoding burden,
+ altough not to the point of a livestream where there is a hard
+ constraint on the frames per second to be encoded.
+
+ why '--aq-mode=2 --aq-strength=1.3' instead of '-profile:v main'?
+ Make up for most of the loss of grain and macroblocking
+ with less computing power.
+ */
+}
+
+/**
+ * A preset optimised for a stillimage audio video
+ */
+function audio (_ffmpeg) {
+ _ffmpeg
+ .preset(veryfast)
+ .outputOption('-tune stillimage')
+}
+
+/**
+ * A toolbox to play with audio
+ */
+namespace audio {
+ export const get = (_ffmpeg, pos: number | string = 0) => {
+ // without position, ffprobe considers the last input only
+ // we make it consider the first input only
+ // if you pass a file path to pos, then ffprobe acts on that file directly
+ return new Promise<{ absolutePath: string, audioStream?: any }>((res, rej) => {
+ _ffmpeg.ffprobe(pos, (err,data) => {
+ if (err) return rej(err)
+
+ if ('streams' in data) {
+ const audioStream = data['streams'].find(stream => stream['codec_type'] === 'audio')
+ if (audioStream) {
+ return res({
+ absolutePath: data.format.filename,
+ audioStream
+ })
+ }
+ }
+ return res({ absolutePath: data.format.filename })
+ })
+ })
+ }
+
+ export namespace bitrate {
+ export const baseKbitrate = 384
+
+ const toBits = (kbits: number): number => { return kbits * 8000 }
+
+ export const aac = (bitrate: number): number => {
+ switch (true) {
+ case bitrate > toBits(baseKbitrate):
+ return baseKbitrate
+ default:
+ return -1 // we interpret it as a signal to copy the audio stream as is
+ }
+ }
+
+ export const mp3 = (bitrate: number): number => {
+ /*
+ a 192kbit/sec mp3 doesn't hold as much information as a 192kbit/sec aac.
+ That's why, when using aac, we can go to lower kbit/sec. The equivalences
+ made here are not made to be accurate, especially with good mp3 encoders.
+ */
+ switch (true) {
+ case bitrate <= toBits(192):
+ return 128
+ case bitrate <= toBits(384):
+ return 256
+ default:
+ return baseKbitrate
+ }
+ }
+ }
+}
+
+/**
+ * Standard profile, with variable bitrate audio and faststart.
+ *
+ * As for the audio, quality '5' is the highest and ensures 96-112kbps/channel
+ * See https://trac.ffmpeg.org/wiki/Encode/AAC#fdk_vbr
+ */
+async function standard (_ffmpeg) {
+ let _bitrate = audio.bitrate.baseKbitrate
+ let localFfmpeg = _ffmpeg
+ .format('mp4')
+ .videoCodec('libx264')
+ .outputOption('-level 3.1') // 3.1 is the minimal ressource allocation for our highest supported resolution
+ .outputOption('-b_strategy 1') // NOTE: b-strategy 1 - heuristic algorythm, 16 is optimal B-frames for it
+ .outputOption('-bf 16') // NOTE: Why 16: https://github.com/Chocobozzz/PeerTube/pull/774. b-strategy 2 -> B-frames<16
+ .outputOption('-map_metadata -1') // strip all metadata
+ .outputOption('-movflags faststart')
+ const _audio = await audio.get(localFfmpeg)
+
+ if (!_audio.audioStream) {
+ return localFfmpeg.noAudio()
+ }
+
+ // we try to reduce the ceiling bitrate by making rough correspondances of bitrates
+ // of course this is far from perfect, but it might save some space in the end
+ if (audio.bitrate[_audio.audioStream['codec_name']]) {
+ _bitrate = audio.bitrate[_audio.audioStream['codec_name']](_audio.audioStream['bit_rate'])
+ if (_bitrate === -1) {
+ return localFfmpeg.audioCodec('copy')
+ }
+ }
+
+ // we favor VBR, if a good AAC encoder is available
+ if ((await checkFFmpegEncoders()).get('libfdk_aac')) {
+ return localFfmpeg
+ .audioCodec('libfdk_aac')
+ .audioQuality(5)
+ }
+
+ return localFfmpeg.audioBitrate(_bitrate)
+}
projects / github / Chocobozzz / PeerTube.git / blobdiff