import * as ffmpeg from 'fluent-ffmpeg' import { dirname, join } from 'path' import { getMaxBitrate, getTargetBitrate, VideoResolution } from '../../shared/models/videos' import { FFMPEG_NICE, VIDEO_TRANSCODING_FPS } from '../initializers/constants' import { processImage } from './image-utils' import { logger } from './logger' import { checkFFmpegEncoders } from '../initializers/checker-before-init' import { readFile, remove, writeFile } from 'fs-extra' import { CONFIG } from '../initializers/config' import { VideoFileMetadata } from '@shared/models/videos/video-file-metadata' /** * A toolbox to play with audio */ namespace audio { export const get = (videoPath: 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 return new Promise<{ absolutePath: string, audioStream?: any }>((res, rej) => { function parseFfprobe (err: any, data: ffmpeg.FfprobeData) { 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 }) } return ffmpeg.ffprobe(videoPath, parseFfprobe) }) } export namespace bitrate { const baseKbitrate = 384 const toBits = (kbits: number) => 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 } } } } 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_NOVIDEO, VideoResolution.H_480P, VideoResolution.H_360P, VideoResolution.H_720P, VideoResolution.H_240P, VideoResolution.H_1080P, VideoResolution.H_4K ] for (const resolution of resolutions) { if (configResolutions[resolution + 'p'] === true && videoFileHeight > resolution) { resolutionsEnabled.push(resolution) } } return resolutionsEnabled } async function getVideoStreamSize (path: string) { const videoStream = await getVideoStreamFromFile(path) return videoStream === null ? { width: 0, height: 0 } : { width: videoStream.width, height: videoStream.height } } async function getVideoStreamCodec (path: string) { const videoStream = await getVideoStreamFromFile(path) if (!videoStream) return '' const videoCodec = videoStream.codec_tag_string const baseProfileMatrix = { High: '6400', Main: '4D40', Baseline: '42E0' } let baseProfile = baseProfileMatrix[videoStream.profile] if (!baseProfile) { logger.warn('Cannot get video profile codec of %s.', path, { videoStream }) baseProfile = baseProfileMatrix['High'] // Fallback } let level = videoStream.level.toString(16) if (level.length === 1) level = `0${level}` return `${videoCodec}.${baseProfile}${level}` } async function getAudioStreamCodec (path: string) { const { audioStream } = await audio.get(path) if (!audioStream) return '' const audioCodec = audioStream.codec_name if (audioCodec === 'aac') return 'mp4a.40.2' logger.warn('Cannot get audio codec of %s.', path, { audioStream }) return 'mp4a.40.2' // Fallback } async function getVideoFileResolution (path: string) { const size = await getVideoStreamSize(path) return { videoFileResolution: Math.min(size.height, size.width), isPortraitMode: size.height > size.width } } async function getVideoFileFPS (path: string) { const videoStream = await getVideoStreamFromFile(path) if (videoStream === null) return 0 for (const key of [ 'avg_frame_rate', 'r_frame_rate' ]) { 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) } return 0 } async function getMetadataFromFile (path: string, cb = metadata => metadata) { return new Promise((res, rej) => { ffmpeg.ffprobe(path, (err, metadata) => { if (err) return rej(err) return res(cb(new VideoFileMetadata(metadata))) }) }) } async function getVideoFileBitrate (path: string) { return getMetadataFromFile(path, metadata => metadata.format.bit_rate) } function getDurationFromVideoFile (path: string) { return getMetadataFromFile(path, metadata => Math.floor(metadata.format.duration)) } function getVideoStreamFromFile (path: string) { return getMetadataFromFile(path, metadata => metadata.streams.find(s => s.codec_type === 'video') || null) } async function generateImageFromVideoFile (fromPath: string, folder: string, imageName: string, size: { width: number, height: number }) { const pendingImageName = 'pending-' + imageName const options = { filename: pendingImageName, count: 1, folder } const pendingImagePath = join(folder, pendingImageName) try { await new Promise((res, rej) => { ffmpeg(fromPath, { niceness: FFMPEG_NICE.THUMBNAIL }) .on('error', rej) .on('end', () => res(imageName)) .thumbnail(options) }) const destination = join(folder, imageName) await processImage(pendingImagePath, destination, size) } catch (err) { logger.error('Cannot generate image from video %s.', fromPath, { err }) try { await remove(pendingImagePath) } catch (err) { logger.debug('Cannot remove pending image path after generation error.', { err }) } } } type TranscodeOptionsType = 'hls' | 'quick-transcode' | 'video' | 'merge-audio' | 'only-audio' interface BaseTranscodeOptions { type: TranscodeOptionsType inputPath: string outputPath: string resolution: VideoResolution isPortraitMode?: boolean } interface HLSTranscodeOptions extends BaseTranscodeOptions { type: 'hls' copyCodecs: boolean hlsPlaylist: { videoFilename: string } } interface QuickTranscodeOptions extends BaseTranscodeOptions { type: 'quick-transcode' } interface VideoTranscodeOptions extends BaseTranscodeOptions { type: 'video' } interface MergeAudioTranscodeOptions extends BaseTranscodeOptions { type: 'merge-audio' audioPath: string } interface OnlyAudioTranscodeOptions extends BaseTranscodeOptions { type: 'only-audio' } type TranscodeOptions = HLSTranscodeOptions | VideoTranscodeOptions | MergeAudioTranscodeOptions | OnlyAudioTranscodeOptions | QuickTranscodeOptions function transcode (options: TranscodeOptions) { return new Promise(async (res, rej) => { try { let command = ffmpeg(options.inputPath, { niceness: FFMPEG_NICE.TRANSCODING }) .output(options.outputPath) if (options.type === 'quick-transcode') { command = buildQuickTranscodeCommand(command) } else if (options.type === 'hls') { command = await buildHLSCommand(command, options) } else if (options.type === 'merge-audio') { command = await buildAudioMergeCommand(command, options) } else if (options.type === 'only-audio') { command = buildOnlyAudioCommand(command, options) } else { command = await buildx264Command(command, options) } if (CONFIG.TRANSCODING.THREADS > 0) { // if we don't set any threads ffmpeg will chose automatically command = command.outputOption('-threads ' + CONFIG.TRANSCODING.THREADS) } command .on('error', (err, stdout, stderr) => { logger.error('Error in transcoding job.', { stdout, stderr }) return rej(err) }) .on('end', () => { return fixHLSPlaylistIfNeeded(options) .then(() => res()) .catch(err => rej(err)) }) .run() } catch (err) { return rej(err) } }) } async function canDoQuickTranscode (path: string): Promise { // NOTE: This could be optimized by running ffprobe only once (but it runs fast anyway) const videoStream = await getVideoStreamFromFile(path) const parsedAudio = await audio.get(path) const fps = await getVideoFileFPS(path) const bitRate = await getVideoFileBitrate(path) const resolution = await getVideoFileResolution(path) // check video params if (videoStream == null) return false if (videoStream['codec_name'] !== 'h264') return false if (videoStream['pix_fmt'] !== 'yuv420p') return false if (fps < VIDEO_TRANSCODING_FPS.MIN || fps > VIDEO_TRANSCODING_FPS.MAX) return false if (bitRate > getMaxBitrate(resolution.videoFileResolution, fps, VIDEO_TRANSCODING_FPS)) return false // check audio params (if audio stream exists) if (parsedAudio.audioStream) { if (parsedAudio.audioStream['codec_name'] !== 'aac') return false const maxAudioBitrate = audio.bitrate['aac'](parsedAudio.audioStream['bit_rate']) if (maxAudioBitrate !== -1 && parsedAudio.audioStream['bit_rate'] > maxAudioBitrate) return false } return true } function getClosestFramerateStandard (fps: number, type: 'HD_STANDARD' | 'STANDARD'): number { return VIDEO_TRANSCODING_FPS[type].slice(0) .sort((a, b) => fps % a - fps % b)[0] } // --------------------------------------------------------------------------- export { getVideoStreamCodec, getAudioStreamCodec, getVideoStreamSize, getVideoFileResolution, getMetadataFromFile, getDurationFromVideoFile, generateImageFromVideoFile, TranscodeOptions, TranscodeOptionsType, transcode, getVideoFileFPS, computeResolutionsToTranscode, audio, getVideoFileBitrate, canDoQuickTranscode } // --------------------------------------------------------------------------- async function buildx264Command (command: ffmpeg.FfmpegCommand, options: TranscodeOptions) { let fps = await getVideoFileFPS(options.inputPath) if ( // On small/medium resolutions, limit FPS options.resolution !== undefined && options.resolution < VIDEO_TRANSCODING_FPS.KEEP_ORIGIN_FPS_RESOLUTION_MIN && fps > VIDEO_TRANSCODING_FPS.AVERAGE ) { // Get closest standard framerate by modulo: downsampling has to be done to a divisor of the nominal fps value fps = getClosestFramerateStandard(fps, 'STANDARD') } command = await presetH264(command, options.inputPath, options.resolution, fps) if (options.resolution !== undefined) { // '?x720' or '720x?' for example const size = options.isPortraitMode === true ? `${options.resolution}x?` : `?x${options.resolution}` command = command.size(size) } if (fps) { // Hard FPS limits if (fps > VIDEO_TRANSCODING_FPS.MAX) fps = getClosestFramerateStandard(fps, 'HD_STANDARD') else if (fps < VIDEO_TRANSCODING_FPS.MIN) fps = VIDEO_TRANSCODING_FPS.MIN command = command.withFPS(fps) } return command } async function buildAudioMergeCommand (command: ffmpeg.FfmpegCommand, options: MergeAudioTranscodeOptions) { command = command.loop(undefined) command = await presetH264VeryFast(command, options.audioPath, options.resolution) command = command.input(options.audioPath) .videoFilter('scale=trunc(iw/2)*2:trunc(ih/2)*2') // Avoid "height not divisible by 2" error .outputOption('-tune stillimage') .outputOption('-shortest') return command } function buildOnlyAudioCommand (command: ffmpeg.FfmpegCommand, options: OnlyAudioTranscodeOptions) { command = presetOnlyAudio(command) return command } function buildQuickTranscodeCommand (command: ffmpeg.FfmpegCommand) { command = presetCopy(command) command = command.outputOption('-map_metadata -1') // strip all metadata .outputOption('-movflags faststart') return command } async function buildHLSCommand (command: ffmpeg.FfmpegCommand, options: HLSTranscodeOptions) { const videoPath = getHLSVideoPath(options) if (options.copyCodecs) command = presetCopy(command) else command = await buildx264Command(command, options) 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') .outputOption('-f hls') .outputOption('-hls_flags single_file') return command } function getHLSVideoPath (options: HLSTranscodeOptions) { return `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}` } async function fixHLSPlaylistIfNeeded (options: TranscodeOptions) { if (options.type !== 'hls') return const fileContent = await readFile(options.outputPath) const videoFileName = options.hlsPlaylist.videoFilename const videoFilePath = getHLSVideoPath(options) // Fix wrong mapping with some ffmpeg versions const newContent = fileContent.toString() .replace(`#EXT-X-MAP:URI="${videoFilePath}",`, `#EXT-X-MAP:URI="${videoFileName}",`) await writeFile(options.outputPath, newContent) } /** * 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. */ async function presetH264VeryFast (command: ffmpeg.FfmpegCommand, input: string, resolution: VideoResolution, fps?: number) { let localCommand = await presetH264(command, input, resolution, fps) localCommand = localCommand.outputOption('-preset:v veryfast') /* 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, although not to the point of a livestream where there is a hard constraint on the frames per second to be encoded. */ return localCommand } /** * 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 presetH264 (command: ffmpeg.FfmpegCommand, input: string, resolution: VideoResolution, fps?: number) { let localCommand = command .format('mp4') .videoCodec('libx264') .outputOption('-level 3.1') // 3.1 is the minimal resource allocation for our highest supported resolution .outputOption('-b_strategy 1') // NOTE: b-strategy 1 - heuristic algorithm, 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') const parsedAudio = await audio.get(input) 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) } else { // we try to reduce the ceiling bitrate by making rough matches of bitrates // of course this is far from perfect, but it might save some space in the end localCommand = localCommand.audioCodec('aac') const audioCodecName = parsedAudio.audioStream['codec_name'] if (audio.bitrate[audioCodecName]) { const bitrate = audio.bitrate[audioCodecName](parsedAudio.audioStream['bit_rate']) if (bitrate !== undefined && bitrate !== -1) localCommand = localCommand.audioBitrate(bitrate) } } if (fps) { // 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) 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 localCommand = localCommand.outputOption(`-g ${fps * 2}`) } return localCommand } function presetCopy (command: ffmpeg.FfmpegCommand): ffmpeg.FfmpegCommand { return command .format('mp4') .videoCodec('copy') .audioCodec('copy') } function presetOnlyAudio (command: ffmpeg.FfmpegCommand): ffmpeg.FfmpegCommand { return command .format('mp4') .audioCodec('copy') .noVideo() }