PeerTube/server/helpers/ffmpeg-utils.ts

377 lines
12 KiB
TypeScript
Raw Normal View History

import * as ffmpeg from 'fluent-ffmpeg'
2019-01-29 08:37:25 +01:00
import { dirname, join } from 'path'
2018-10-18 09:44:43 +02:00
import { getTargetBitrate, VideoResolution } from '../../shared/models/videos'
2018-11-19 17:08:18 +01:00
import { CONFIG, FFMPEG_NICE, VIDEO_TRANSCODING_FPS } from '../initializers/constants'
2018-02-27 11:29:24 +01:00
import { processImage } from './image-utils'
import { logger } from './logger'
import { checkFFmpegEncoders } from '../initializers/checker-before-init'
2018-08-27 16:23:34 +02:00
import { remove } from 'fs-extra'
2018-08-14 15:28:30 +02:00
function computeResolutionsToTranscode (videoFileHeight: number) {
const resolutionsEnabled: number[] = []
const configResolutions = CONFIG.TRANSCODING.RESOLUTIONS
// Put in the order we want to proceed jobs
const resolutions = [
VideoResolution.H_480P,
VideoResolution.H_360P,
VideoResolution.H_720P,
VideoResolution.H_240P,
VideoResolution.H_1080P
]
for (const resolution of resolutions) {
if (configResolutions[ resolution + 'p' ] === true && videoFileHeight > resolution) {
resolutionsEnabled.push(resolution)
}
}
return resolutionsEnabled
}
2019-01-29 08:37:25 +01:00
async function getVideoFileSize (path: string) {
2018-02-26 10:48:53 +01:00
const videoStream = await getVideoFileStream(path)
2018-02-27 15:57:28 +01:00
return {
2019-01-29 08:37:25 +01:00
width: videoStream.width,
height: videoStream.height
}
}
async function getVideoFileResolution (path: string) {
const size = await getVideoFileSize(path)
return {
videoFileResolution: Math.min(size.height, size.width),
isPortraitMode: size.height > size.width
2018-02-27 15:57:28 +01:00
}
2018-02-26 10:48:53 +01:00
}
2018-02-26 10:48:53 +01:00
async function getVideoFileFPS (path: string) {
const videoStream = await getVideoFileStream(path)
for (const key of [ 'avg_frame_rate', 'r_frame_rate' ]) {
2018-02-26 10:48:53 +01:00
const valuesText: string = videoStream[key]
if (!valuesText) continue
const [ frames, seconds ] = valuesText.split('/')
if (!frames || !seconds) continue
const result = parseInt(frames, 10) / parseInt(seconds, 10)
if (result > 0) return Math.round(result)
2018-02-26 10:48:53 +01:00
}
return 0
}
async function getVideoFileBitrate (path: string) {
return new Promise<number>((res, rej) => {
ffmpeg.ffprobe(path, (err, metadata) => {
if (err) return rej(err)
return res(metadata.format.bit_rate)
})
})
}
function getDurationFromVideoFile (path: string) {
return new Promise<number>((res, rej) => {
ffmpeg.ffprobe(path, (err, metadata) => {
if (err) return rej(err)
return res(Math.floor(metadata.format.duration))
})
})
}
2018-02-27 11:29:24 +01:00
async function generateImageFromVideoFile (fromPath: string, folder: string, imageName: string, size: { width: number, height: number }) {
const pendingImageName = 'pending-' + imageName
const options = {
2018-02-27 11:29:24 +01:00
filename: pendingImageName,
count: 1,
folder
}
2018-02-27 11:29:24 +01:00
const pendingImagePath = join(folder, pendingImageName)
try {
await new Promise<string>((res, rej) => {
2018-07-28 02:59:01 +02:00
ffmpeg(fromPath, { niceness: FFMPEG_NICE.THUMBNAIL })
.on('error', rej)
.on('end', () => res(imageName))
.thumbnail(options)
})
const destination = join(folder, imageName)
await processImage({ path: pendingImagePath }, destination, size)
} catch (err) {
2018-03-26 15:54:13 +02:00
logger.error('Cannot generate image from video %s.', fromPath, { err })
try {
2018-08-27 16:23:34 +02:00
await remove(pendingImagePath)
} catch (err) {
2018-03-26 15:54:13 +02:00
logger.debug('Cannot remove pending image path after generation error.', { err })
}
}
}
type TranscodeOptions = {
inputPath: string
outputPath: string
2019-01-29 08:37:25 +01:00
resolution: VideoResolution
2018-02-27 15:57:28 +01:00
isPortraitMode?: boolean
2019-01-29 08:37:25 +01:00
hlsPlaylist?: {
videoFilename: string
}
}
function transcode (options: TranscodeOptions) {
2018-02-26 10:48:53 +01:00
return new Promise<void>(async (res, rej) => {
2018-10-18 09:44:43 +02:00
try {
let fps = await getVideoFileFPS(options.inputPath)
// On small/medium resolutions, limit FPS
if (
options.resolution !== undefined &&
options.resolution < VIDEO_TRANSCODING_FPS.KEEP_ORIGIN_FPS_RESOLUTION_MIN &&
fps > VIDEO_TRANSCODING_FPS.AVERAGE
) {
fps = VIDEO_TRANSCODING_FPS.AVERAGE
}
2018-10-18 09:44:43 +02:00
let command = ffmpeg(options.inputPath, { niceness: FFMPEG_NICE.TRANSCODING })
.output(options.outputPath)
command = await presetH264(command, options.resolution, fps)
2018-07-28 02:59:01 +02:00
2018-10-18 09:44:43 +02:00
if (CONFIG.TRANSCODING.THREADS > 0) {
// if we don't set any threads ffmpeg will chose automatically
command = command.outputOption('-threads ' + CONFIG.TRANSCODING.THREADS)
}
2018-10-18 09:44:43 +02:00
if (options.resolution !== undefined) {
// '?x720' or '720x?' for example
const size = options.isPortraitMode === true ? `${options.resolution}x?` : `?x${options.resolution}`
command = command.size(size)
}
2018-10-18 09:44:43 +02:00
if (fps) {
// Hard FPS limits
if (fps > VIDEO_TRANSCODING_FPS.MAX) fps = VIDEO_TRANSCODING_FPS.MAX
else if (fps < VIDEO_TRANSCODING_FPS.MIN) fps = VIDEO_TRANSCODING_FPS.MIN
2018-10-18 09:44:43 +02:00
command = command.withFPS(fps)
}
if (options.hlsPlaylist) {
const videoPath = `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}`
2019-01-29 08:37:25 +01:00
command = command.outputOption('-hls_time 4')
.outputOption('-hls_list_size 0')
.outputOption('-hls_playlist_type vod')
.outputOption('-hls_segment_filename ' + videoPath)
.outputOption('-hls_segment_type fmp4')
2019-01-29 08:37:25 +01:00
.outputOption('-f hls')
.outputOption('-hls_flags single_file')
2019-01-29 08:37:25 +01:00
}
2018-10-18 09:44:43 +02:00
command
.on('error', (err, stdout, stderr) => {
logger.error('Error in transcoding job.', { stdout, stderr })
return rej(err)
})
.on('end', res)
.run()
} catch (err) {
return rej(err)
}
})
}
// ---------------------------------------------------------------------------
export {
2019-01-29 08:37:25 +01:00
getVideoFileSize,
2018-02-27 15:57:28 +01:00
getVideoFileResolution,
getDurationFromVideoFile,
generateImageFromVideoFile,
2018-02-26 10:48:53 +01:00
transcode,
2018-07-28 02:59:01 +02:00
getVideoFileFPS,
2018-08-14 15:28:30 +02:00
computeResolutionsToTranscode,
audio,
getVideoFileBitrate
2018-02-26 10:48:53 +01:00
}
// ---------------------------------------------------------------------------
function getVideoFileStream (path: string) {
return new Promise<any>((res, rej) => {
ffmpeg.ffprobe(path, (err, metadata) => {
if (err) return rej(err)
const videoStream = metadata.streams.find(s => s.codec_type === 'video')
2018-12-12 08:55:56 +01:00
if (!videoStream) return rej(new Error('Cannot find video stream of ' + path))
2018-02-26 10:48:53 +01:00
return res(videoStream)
})
})
}
/**
* 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.
*/
2018-10-18 09:44:43 +02:00
async function presetH264VeryFast (command: ffmpeg.FfmpegCommand, resolution: VideoResolution, fps: number): Promise<ffmpeg.FfmpegCommand> {
let localCommand = await presetH264(command, resolution, fps)
localCommand = localCommand.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.
*/
2018-10-18 09:44:43 +02:00
return localCommand
}
/**
* A preset optimised for a stillimage audio video
*/
2018-10-18 09:44:43 +02:00
async function presetStillImageWithAudio (
command: ffmpeg.FfmpegCommand,
resolution: VideoResolution,
fps: number
): Promise<ffmpeg.FfmpegCommand> {
let localCommand = await presetH264VeryFast(command, resolution, fps)
localCommand = localCommand.outputOption('-tune stillimage')
return localCommand
}
/**
* A toolbox to play with audio
*/
namespace audio {
2018-10-18 09:44:43 +02:00
export const get = (option: ffmpeg.FfmpegCommand | string) => {
// 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
2018-07-28 02:59:01 +02:00
return new Promise<{ absolutePath: string, audioStream?: any }>((res, rej) => {
2018-10-18 09:44:43 +02:00
function parseFfprobe (err: any, data: ffmpeg.FfprobeData) {
2018-07-28 02:59:01 +02:00
if (err) return rej(err)
if ('streams' in data) {
2018-10-18 09:44:43 +02:00
const audioStream = data.streams.find(stream => stream['codec_type'] === 'audio')
2018-07-28 02:59:01 +02:00
if (audioStream) {
return res({
absolutePath: data.format.filename,
audioStream
})
}
2018-07-28 02:59:01 +02:00
}
2018-10-18 09:44:43 +02:00
2018-07-28 02:59:01 +02:00
return res({ absolutePath: data.format.filename })
2018-10-18 09:44:43 +02:00
}
if (typeof option === 'string') {
return ffmpeg.ffprobe(option, parseFfprobe)
}
return option.ffprobe(parseFfprobe)
})
}
export namespace bitrate {
const baseKbitrate = 384
const toBits = (kbits: number): number => { return kbits * 8000 }
export const aac = (bitrate: number): number => {
switch (true) {
2018-07-28 02:59:01 +02:00
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 => {
2018-07-28 02:59:01 +02:00
/*
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
*/
2018-10-18 09:44:43 +02:00
async function presetH264 (command: ffmpeg.FfmpegCommand, resolution: VideoResolution, fps: number): Promise<ffmpeg.FfmpegCommand> {
let localCommand = command
.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('-pix_fmt yuv420p') // allows import of source material with incompatible pixel formats (e.g. MJPEG video)
.outputOption('-map_metadata -1') // strip all metadata
.outputOption('-movflags faststart')
2018-10-18 09:44:43 +02:00
const parsedAudio = await audio.get(localCommand)
2018-10-18 09:44:43 +02:00
if (!parsedAudio.audioStream) {
localCommand = localCommand.noAudio()
} else if ((await checkFFmpegEncoders()).get('libfdk_aac')) { // we favor VBR, if a good AAC encoder is available
localCommand = localCommand
.audioCodec('libfdk_aac')
.audioQuality(5)
2018-10-18 09:44:43 +02:00
} else {
// 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
const audioCodecName = parsedAudio.audioStream[ 'codec_name' ]
let bitrate: number
if (audio.bitrate[ audioCodecName ]) {
2018-12-11 17:48:14 +01:00
localCommand = localCommand.audioCodec('aac')
2018-10-18 09:44:43 +02:00
2018-12-11 17:48:14 +01:00
bitrate = audio.bitrate[ audioCodecName ](parsedAudio.audioStream[ 'bit_rate' ])
if (bitrate !== undefined && bitrate !== -1) localCommand = localCommand.audioBitrate(bitrate)
2018-10-18 09:44:43 +02:00
}
}
// Constrained Encoding (VBV)
// https://slhck.info/video/2017/03/01/rate-control.html
// https://trac.ffmpeg.org/wiki/Limiting%20the%20output%20bitrate
const targetBitrate = getTargetBitrate(resolution, fps, VIDEO_TRANSCODING_FPS)
2018-10-18 09:44:43 +02:00
localCommand = localCommand.outputOptions([`-maxrate ${ targetBitrate }`, `-bufsize ${ targetBitrate * 2 }`])
// Keyframe interval of 2 seconds for faster seeking and resolution switching.
// https://streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval.html
// https://superuser.com/a/908325
2018-10-18 09:44:43 +02:00
localCommand = localCommand.outputOption(`-g ${ fps * 2 }`)
2018-10-18 09:44:43 +02:00
return localCommand
}