PeerTube/server/lib/video-transcoding-profiles.ts

127 lines
3.8 KiB
TypeScript
Raw Normal View History

2020-11-24 16:29:39 +01:00
import { logger } from '@server/helpers/logger'
2020-11-26 11:29:50 +01:00
import { getTargetBitrate, VideoResolution } from '../../shared/models/videos'
2020-11-24 14:08:23 +01:00
import { AvailableEncoders, buildStreamSuffix, EncoderOptionsBuilder } from '../helpers/ffmpeg-utils'
2020-11-24 16:29:39 +01:00
import {
canDoQuickAudioTranscode,
ffprobePromise,
getAudioStream,
getMaxAudioBitrate,
getVideoFileBitrate,
getVideoStreamFromFile
} from '../helpers/ffprobe-utils'
2020-11-24 14:08:23 +01:00
import { VIDEO_TRANSCODING_FPS } from '../initializers/constants'
2020-11-24 16:29:39 +01:00
/**
*
* Available encoders and profiles for the transcoding jobs
* These functions are used by ffmpeg-utils that will get the encoders and options depending on the chosen profile
*
*/
2020-11-24 14:08:23 +01:00
// Resources:
// * https://slhck.info/video/2017/03/01/rate-control.html
// * https://trac.ffmpeg.org/wiki/Limiting%20the%20output%20bitrate
const defaultX264VODOptionsBuilder: EncoderOptionsBuilder = async ({ input, resolution, fps }) => {
2020-11-26 11:29:50 +01:00
const targetBitrate = await buildTargetBitrate({ input, resolution, fps })
if (!targetBitrate) return { outputOptions: [ ] }
2020-11-24 14:08:23 +01:00
return {
outputOptions: [
2020-11-26 11:29:50 +01:00
`-r ${fps}`,
2020-11-24 16:29:39 +01:00
`-maxrate ${targetBitrate}`,
`-bufsize ${targetBitrate * 2}`
2020-11-24 14:08:23 +01:00
]
}
}
const defaultX264LiveOptionsBuilder: EncoderOptionsBuilder = async ({ resolution, fps, streamNum }) => {
const targetBitrate = getTargetBitrate(resolution, fps, VIDEO_TRANSCODING_FPS)
return {
outputOptions: [
2020-11-26 11:29:50 +01:00
`${buildStreamSuffix('-r:v', streamNum)} ${fps}`,
2020-11-24 14:08:23 +01:00
`${buildStreamSuffix('-b:v', streamNum)} ${targetBitrate}`,
2020-11-24 15:22:56 +01:00
`-maxrate ${targetBitrate}`,
`-bufsize ${targetBitrate * 2}`
2020-11-24 14:08:23 +01:00
]
}
}
const defaultAACOptionsBuilder: EncoderOptionsBuilder = async ({ input, streamNum }) => {
2020-11-24 16:29:39 +01:00
const probe = await ffprobePromise(input)
if (await canDoQuickAudioTranscode(input, probe)) {
logger.debug('Copy audio stream %s by AAC encoder.', input)
return { copy: true, outputOptions: [] }
}
const parsedAudio = await getAudioStream(input, probe)
2020-11-24 14:08:23 +01:00
// 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
const audioCodecName = parsedAudio.audioStream['codec_name']
const bitrate = getMaxAudioBitrate(audioCodecName, parsedAudio.bitrate)
2020-11-24 16:29:39 +01:00
logger.debug('Calculating audio bitrate of %s by AAC encoder.', input, { bitrate: parsedAudio.bitrate, audioCodecName })
2020-11-24 14:08:23 +01:00
if (bitrate !== undefined && bitrate !== -1) {
return { outputOptions: [ buildStreamSuffix('-b:a', streamNum), bitrate + 'k' ] }
}
2020-11-24 16:29:39 +01:00
return { outputOptions: [ ] }
2020-11-24 14:08:23 +01:00
}
const defaultLibFDKAACVODOptionsBuilder: EncoderOptionsBuilder = ({ streamNum }) => {
return { outputOptions: [ buildStreamSuffix('-q:a', streamNum), '5' ] }
}
const availableEncoders: AvailableEncoders = {
vod: {
libx264: {
default: defaultX264VODOptionsBuilder
},
aac: {
default: defaultAACOptionsBuilder
},
libfdk_aac: {
default: defaultLibFDKAACVODOptionsBuilder
}
},
live: {
libx264: {
default: defaultX264LiveOptionsBuilder
},
aac: {
default: defaultAACOptionsBuilder
}
}
}
// ---------------------------------------------------------------------------
export {
availableEncoders
}
// ---------------------------------------------------------------------------
2020-11-26 11:29:50 +01:00
async function buildTargetBitrate (options: {
input: string
resolution: VideoResolution
fps: number
}) {
const { input, resolution, fps } = options
const probe = await ffprobePromise(input)
const videoStream = await getVideoStreamFromFile(input, probe)
if (!videoStream) return undefined
const targetBitrate = getTargetBitrate(resolution, fps, VIDEO_TRANSCODING_FPS)
// Don't transcode to an higher bitrate than the original file
const fileBitrate = await getVideoFileBitrate(input, probe)
return Math.min(targetBitrate, fileBitrate)
}