feat(xgplayer-hls xgplayer-transmuxer): HLS 音视频LargeGAP优化处理

fixtures/hls/index.js

@@ -14,7 +14,8 @@ function defaultOpt() {
     preloadTime: 180,
     bufferBehind: 10,
     maxJumpDistance: 3,
-    startTime: 0
+    startTime: 0,
+    forceFixLargeGap:false,
   }
 }
 var cachedOpt = localStorage.getItem('xg:test:hls:opt')

packages/xgplayer-hls/src/hls/buffer-service/index.js

@@ -78,10 +78,10 @@ export class BufferService {
     const chunk = videoChunk || audioChunk
     if (!chunk) return
     if (TsDemuxer.probe(chunk)) {
-      if (!this._transmuxer) this._transmuxer = new Transmuxer(this.hls, false, !this._softVideo)
+      if (!this._transmuxer) this._transmuxer = new Transmuxer(this.hls, false, !this._softVideo, this.hls.config.forceFixLargeGap)
     } else if (MP4Parser.probe(chunk)) {
       if (this._softVideo) {
-        if (!this._transmuxer) this._transmuxer = new Transmuxer(this.hls, true)
+        if (!this._transmuxer) this._transmuxer = new Transmuxer(this.hls, true, null, this.hls.config.forceFixLargeGap)
       } else {
         this._directAppend = true
         let mix = false

packages/xgplayer-hls/src/hls/buffer-service/transmuxer/index.js

@@ -7,8 +7,9 @@ const logger = new Logger('Transmuxer')
 export class Transmuxer {
   _initSegmentId = ''
 
-  constructor (hls, isMP4, needRemux) {
+  constructor (hls, isMP4, needRemux, forceFixLargeGap) {
     this.hls = hls
+    this.forceFixLargeGap = forceFixLargeGap
     this._demuxer = isMP4 ? new FMP4Demuxer() : new TsDemuxer()
     this._isMP4 = isMP4
     if (needRemux) this._remuxer = new FMP4Remuxer(this._demuxer.videoTrack, this._demuxer.audioTrack)
@@ -20,7 +21,7 @@ export class Transmuxer {
       if (this._isMP4) {
         demuxer.demux(videoChunk, audioChunk)
       } else {
-        demuxer.demuxAndFix(concatUint8Array(videoChunk, audioChunk), discontinuity, contiguous, startTime)
+        demuxer.demuxAndFix(concatUint8Array(videoChunk, audioChunk), discontinuity, contiguous, startTime, this.forceFixLargeGap)
       }
     } catch (error) {
       throw new StreamingError(ERR.DEMUX, ERR.SUB_TYPES.HLS, error)

packages/xgplayer-hls/src/hls/config.js

@@ -26,6 +26,7 @@
  *  preferMMS?: boolean
  *  preferMMSStreaming?: boolean,
  *  mseLowLatency?: boolean,
+ * forceFixLargeGap?:boolean,
  * }} HlsOption
  */
 
@@ -57,6 +58,7 @@ export function getConfig (cfg) {
     preferMMS: false,
     preferMMSStreaming: false,
     mseLowLatency: true, // mse 低延迟模式渲染 https://issues.chromium.org/issues/41161663
+    forceFixLargeGap:false, // 强制修复音视频PTS LargeGap, PTS从0开始
     ...cfg,
     media
   }

packages/xgplayer-transmuxer/src/mpeg-ts/fixer.js

@@ -16,6 +16,8 @@ export class TsFixer {
     this.metadataTrack = metadataTrack
 
     this._baseDts = -1
+    this._baseVideoDts = -1
+    this._baseAudioDts = -1
     this._baseDtsInited = false
 
     this._audioNextPts = undefined
@@ -27,9 +29,11 @@ export class TsFixer {
     this._lastAudioExceptionGapDot = 0
     this._lastAudioExceptionOverlapDot = 0
     this._lastAudioExceptionLargeGapDot = 0
+
+    this._needForceFixLargeGap = false
   }
 
-  fix (startTime = 0, discontinuity = false, contiguous = true) {
+  fix (startTime = 0, discontinuity = false, contiguous = true, forceFixLargeGap = false) {
     startTime = Math.round(startTime * 90000)
     const videoTrack = this.videoTrack
     const audioTrack = this.audioTrack
@@ -41,7 +45,7 @@ export class TsFixer {
 
     const firstVideoSample = vSamples[0]
     const firstAudioSample = aSamples[0]
-
+    this._needForceFixLargeGap = forceFixLargeGap
     // consider av delta
     let vaDelta = 0
 
@@ -57,6 +61,8 @@ export class TsFixer {
     if (discontinuity) {
       this._calculateBaseDts(this.audioTrack, this.videoTrack)
       this._baseDts -= startTime
+      this._baseAudioDts -= startTime
+      this._baseVideoDts -= startTime
     }
 
     // id discontinue, recalc nextDts, consider av delta of firstframe
@@ -72,6 +78,10 @@ export class TsFixer {
       this._videoNextDts = vaDelta > 0 ? startTime + vaDelta : startTime
       this._audioNextPts = vaDelta > 0 ? startTime : startTime - vaDelta
 
+      if (this._needForceFixLargeGap){
+        this._videoNextDts = 0
+        this._audioNextPts = 0
+      }
       const vDeltaToNextDts = firstVideoSample ? firstVideoSample.dts - this._baseDts - this._videoNextDts : 0
       const aDeltaToNextDts = firstAudioSample ? firstAudioSample.pts - this._baseDts - this._audioNextPts : 0
 
@@ -109,8 +119,8 @@ export class TsFixer {
 
     if (!samples.length) return
     samples.forEach(x => {
-      x.dts -= this._baseDts
-      x.pts -= this._baseDts
+      x.dts -= this._needForceFixLargeGap ? this._baseVideoDts : this._baseDts
+      x.pts -= this._needForceFixLargeGap ? this._baseVideoDts : this._baseDts
     })
 
     if (this._videoNextDts === undefined) {
@@ -220,7 +230,7 @@ export class TsFixer {
 
     if (!samples.length) return
     samples.forEach(x => {
-      x.pts -= this._baseDts
+      x.pts -= this._needForceFixLargeGap ? this._baseAudioDts : this._baseDts
       x.dts = x.pts
     })
 
@@ -240,16 +250,18 @@ export class TsFixer {
 
     if (audioSamps.length) {
       audioTrack.baseDts = audioBasePts = audioSamps[0].pts
+      this._baseAudioDts = audioBasePts
     }
 
     if (videoSamps.length) {
       videoTrack.baseDts = videoBaseDts = videoSamps[0].dts
+      this._baseVideoDts = videoBaseDts
     }
 
     this._baseDts = Math.min(audioBasePts, videoBaseDts)
 
     const delta = videoBaseDts - audioBasePts
-
+    let largeGap = false
     if (Number.isFinite(delta) && Math.abs(delta) > LARGE_AV_FIRST_FRAME_GAP) {
       videoTrack.warnings.push({
         type: WarningType.LARGE_AV_SHIFT,
@@ -258,8 +270,15 @@ export class TsFixer {
         baseDts: this._baseDts,
         delta
       })
+      largeGap = true
+    }
+    if (!this._baseDtsInited){
+      if (largeGap && this._needForceFixLargeGap) {
+        this._needForceFixLargeGap = true
+      } else {
+        this._needForceFixLargeGap = false
+      }
     }
-
     this._baseDtsInited = true
     return true
   }

packages/xgplayer-transmuxer/src/mpeg-ts/index.js

@@ -155,8 +155,8 @@ export class TsDemuxer {
    * @param {boolean} [discontinuity=false]
    * @param {boolean} [contiguous=true]
    */
-  fix (startTime, discontinuity, contiguous) {
-    this._fixer.fix(startTime, discontinuity, contiguous)
+  fix (startTime, discontinuity, contiguous, forceFixLargeGap) {
+    this._fixer.fix(startTime, discontinuity, contiguous, forceFixLargeGap)
     return {
       videoTrack: this.videoTrack,
       audioTrack: this.audioTrack,
@@ -170,9 +170,9 @@ export class TsDemuxer {
    * @param {boolean} [contiguous=true]
    * @param {number} [startTime=0]
    */
-  demuxAndFix (data, discontinuity, contiguous, startTime) {
+  demuxAndFix (data, discontinuity, contiguous, startTime, forceFixLargeGap) {
     this.demux(data, discontinuity, contiguous)
-    return this.fix(startTime, discontinuity, contiguous)
+    return this.fix(startTime, discontinuity, contiguous, forceFixLargeGap)
   }
 
   /**