}
}
-type TranscodeOptions = {
+type TranscodeOptionsType = 'hls' | 'quick-transcode' | 'video' | 'merge-audio'
+
+interface BaseTranscodeOptions {
+ type: TranscodeOptionsType
inputPath: string
outputPath: string
resolution: VideoResolution
isPortraitMode?: boolean
- doQuickTranscode?: Boolean
+}
- hlsPlaylist?: {
+interface HLSTranscodeOptions extends BaseTranscodeOptions {
+ type: 'hls'
+ 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
+}
+
+type TranscodeOptions = HLSTranscodeOptions | VideoTranscodeOptions | MergeAudioTranscodeOptions | QuickTranscodeOptions
+
function transcode (options: TranscodeOptions) {
return new Promise<void>(async (res, rej) => {
try {
let command = ffmpeg(options.inputPath, { niceness: FFMPEG_NICE.TRANSCODING })
.output(options.outputPath)
- if (options.doQuickTranscode) {
- if (options.hlsPlaylist) {
- throw(Error("Quick transcode and HLS can't be used at the same time"))
- }
-
- command
- .format('mp4')
- .addOption('-c:v copy')
- .addOption('-c:a copy')
- .outputOption('-map_metadata -1') // strip all metadata
- .outputOption('-movflags faststart')
- } else if (options.hlsPlaylist) {
+ if (options.type === 'quick-transcode') {
+ command = await buildQuickTranscodeCommand(command)
+ } else if (options.type === 'hls') {
command = await buildHLSCommand(command, options)
+ } else if (options.type === 'merge-audio') {
+ command = await buildAudioMergeCommand(command, options)
} else {
command = await buildx264Command(command, options)
}
return rej(err)
})
.on('end', () => {
- return onTranscodingSuccess(options)
+ return fixHLSPlaylistIfNeeded(options)
.then(() => res())
.catch(err => rej(err))
})
getVideoFileResolution,
getDurationFromVideoFile,
generateImageFromVideoFile,
+ TranscodeOptions,
+ TranscodeOptionsType,
transcode,
getVideoFileFPS,
computeResolutionsToTranscode,
// ---------------------------------------------------------------------------
-async function buildx264Command (command: ffmpeg.FfmpegCommand, options: TranscodeOptions) {
+async function buildx264Command (command: ffmpeg.FfmpegCommand, options: VideoTranscodeOptions) {
let fps = await getVideoFileFPS(options.inputPath)
// On small/medium resolutions, limit FPS
if (
fps = VIDEO_TRANSCODING_FPS.AVERAGE
}
- command = await presetH264(command, options.resolution, fps)
+ command = await presetH264(command, options.inputPath, options.resolution, fps)
if (options.resolution !== undefined) {
// '?x720' or '720x?' for example
return command
}
-async function buildHLSCommand (command: ffmpeg.FfmpegCommand, options: TranscodeOptions) {
+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
+}
+
+async function buildQuickTranscodeCommand (command: ffmpeg.FfmpegCommand) {
+ command = await 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)
command = await presetCopy(command)
return command
}
-function getHLSVideoPath (options: TranscodeOptions) {
+function getHLSVideoPath (options: HLSTranscodeOptions) {
return `${dirname(options.outputPath)}/${options.hlsPlaylist.videoFilename}`
}
-async function onTranscodingSuccess (options: TranscodeOptions) {
- if (!options.hlsPlaylist) return
+async function fixHLSPlaylistIfNeeded (options: TranscodeOptions) {
+ if (options.type !== 'hls') return
- // Fix wrong mapping with some ffmpeg versions
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}",`)
* and quality. Superfast and ultrafast will give you better
* performance, but then quality is noticeably worse.
*/
-async function presetH264VeryFast (command: ffmpeg.FfmpegCommand, resolution: VideoResolution, fps: number): Promise<ffmpeg.FfmpegCommand> {
- let localCommand = await presetH264(command, resolution, fps)
+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')
- .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
+ although 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.
*/
return localCommand
}
-/**
- * A preset optimised for a stillimage audio video
- */
-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 {
- export const get = (option: ffmpeg.FfmpegCommand | string) => {
+ export const get = (option: 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 res({ absolutePath: data.format.filename })
}
- if (typeof option === 'string') {
- return ffmpeg.ffprobe(option, parseFfprobe)
- }
-
- return option.ffprobe(parseFfprobe)
+ return ffmpeg.ffprobe(option, parseFfprobe)
})
}
* 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, resolution: VideoResolution, fps: number): Promise<ffmpeg.FfmpegCommand> {
+async function presetH264 (command: ffmpeg.FfmpegCommand, input: string, resolution: VideoResolution, fps?: number) {
let localCommand = command
.format('mp4')
.videoCodec('libx264')
.outputOption('-map_metadata -1') // strip all metadata
.outputOption('-movflags faststart')
- const parsedAudio = await audio.get(localCommand)
+ const parsedAudio = await audio.get(input)
if (!parsedAudio.audioStream) {
localCommand = localCommand.noAudio()
.audioCodec('libfdk_aac')
.audioQuality(5)
} else {
- // we try to reduce the ceiling bitrate by making rough correspondances of bitrates
+ // 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' ]
- let bitrate: number
- if (audio.bitrate[ audioCodecName ]) {
- localCommand = localCommand.audioCodec('aac')
- bitrate = audio.bitrate[ audioCodecName ](parsedAudio.audioStream[ 'bit_rate' ])
+ if (audio.bitrate[ audioCodecName ]) {
+ const bitrate = audio.bitrate[ audioCodecName ](parsedAudio.audioStream[ 'bit_rate' ])
if (bitrate !== undefined && bitrate !== -1) localCommand = localCommand.audioBitrate(bitrate)
}
}
- // 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 }`)
+ 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
}