不连续的HLS在缓冲区中卡住

Question

我们正在使用JWPlayer 8.9.0，并尝试在我们的视频中插入广告。我们使用的是EXT-X-DISCONTINUITY，但很明显，当我们开始做广告时，播放器不再显示缓冲状态。

这是我们的播放列表的一个例子：

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-TARGETDURATION:16
#EXT-X-PLAYLIST-TYPE:VOD
#EXTINF:14.557178,
https://slave2.example.com/hls/output1/output_000.ts
#EXTINF:1.376467,
https://slave3.example.com/hls/output1/output_001.ts
#EXT-X-DISCONTINUITY
#EXTINF:8.050244,
https://slave2.example.com/hls/HLSad/output_000.ts
#EXTINF:4.880200,
https://slave2.example.com/hls/HLSad/output_001.ts
#EXTINF:7.090889,
https://slave2.example.com/hls/HLSad/output_002.ts
#EXTINF:5.881267,
https://slave2.example.com/hls/output1/output_002.ts
#EXTINF:5.672711,
https://slave3.example.com/hls/output1/output_003.ts
#EXT-X-DISCONTINUITY
#EXTINF:8.050244,
https://slave2.example.com/hls/HLSad/output_000.ts
#EXTINF:4.880200,
https://slave2.example.com/hls/HLSad/output_001.ts
#EXTINF:7.090889,
https://slave2.example.com/hls/HLSad/output_002.ts
#EXTINF:5.714422,
https://slave2.example.com/hls/output1/output_004.ts
#EXTINF:4.755067,
https://slave3.example.com/hls/output1/output_005.ts
[...]
#EXT-X-ENDLIST

这是JS控制台告诉我们的：

[log] > audio sampling rate : 48000
9512e6e5-eff6-4f75-806f-a367785315b7:1 [log] > manifest codec:undefined,ADTS data:type:2,sampleingIndex:3[48000Hz],channelConfig:2
9512e6e5-eff6-4f75-806f-a367785315b7:1 [log] > parsed codec:mp4a.40.5,rate:48000,nb channel:2
9512e6e5-eff6-4f75-806f-a367785315b7:1 [log] > audio sampling rate : 48000
9512e6e5-eff6-4f75-806f-a367785315b7:1 [log] > AVC:59 ms overlapping between fragments detected
9512e6e5-eff6-4f75-806f-a367785315b7:1 [log] > Video/PTS/DTS adjusted: 15958/15933,delta:-59 ms

而Chrome媒体控制台显示：

1.414   kPlay   
{}

17.280  kBufferingStateChanged  
{audio_buffering_state: {reason: "DEMUXER_UNDERFLOW", state: "BUFFERING_HAVE_NOTHING"}}

17.280  kBufferingStateChanged  
{,…}
pipeline_buffering_state: {for_suspended_start: false, reason: "DEMUXER_UNDERFLOW", state: "BUFFERING_HAVE_NOTHING"}
for_suspended_start: false
reason: "DEMUXER_UNDERFLOW"
state: "BUFFERING_HAVE_NOTHING"

考虑到我们要在播放列表中“合并”的两个视频具有相同的音视频特性(编解码器、码率、分辨率等)，为什么这不起作用？谢谢

Answer 1

我遇到了类似的问题，并通过以下方式解决了它：

在您的播放列表文件中添加"#EXT-X-DISCONTINUITY-SEQUENCE“，如下所示：

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-DISCONTINUITY-SEQUENCE:0
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-TARGETDURATION:16
#EXT-X-PLAYLIST-TYPE:VOD
#EXTINF:14.557178,
https://slave2.example.com/hls/output1/output_000.ts
#EXTINF:1.376467,
https://slave3.example.com/hls/output1/output_001.ts
#EXT-X-DISCONTINUITY
#EXTINF:8.050244,
https://slave2.example.com/hls/HLSad/output_000.ts
#EXTINF:4.880200,
https://slave2.example.com/hls/HLSad/output_001.ts

无论您从播放列表文件中删除"#EXT-X-DISCONTINUITY“，请将此字段的值增加1。