EXT-X-TARGETDURATION is big on playlist

Wowza Streaming Engine
1

We are seeing “weird” large EXT-X-TARGETDURATION value in our transcoder m3u8 list for live stream. About 1 out of 3 m3u8 files, we see very large EXT-X-TARGETDURATION value of 10 seconds. The other times, we see 2 seconds. Why the value is not matching our settings in cupertinoChunkDurationTarget of 1000? and any idea how to set it to be max 1 second as specified in our cupertinoChunkDurationTarget?

We are using wowza 4.4.1

===our config file settings===

cupertinoChunkDurationTarget

1000

Integer

cupertinoMaxChunkCount

5

Integer

cupertinoPlaylistChunkCount

4

Integer

cupertinoRepeaterChunkCount

4

Integer

cupertinoCalculateChunkIDBasedOnTimecode

false

Boolean

cupertinoOnChunkStartResetCounter

false

Boolean

===normal playlist===

#EXTM3U

#EXT-X-VERSION:3

#EXT-X-TARGETDURATION:2

#EXT-X-MEDIA-SEQUENCE:130

#EXTINF:0.916,

media_w1439163330_b748000_130.ts

#EXTINF:1.337,

media_w1439163330_b748000_131.ts

#EXTINF:0.882,

media_w1439163330_b748000_132.ts

#EXTINF:1.072,

media_w1439163330_b748000_133.ts

====Large duration playlist=====

#EXTM3U

#EXT-X-VERSION:3

#EXT-X-TARGETDURATION:10

#EXT-X-MEDIA-SEQUENCE:132

#EXTINF:0.882,

media_w1439163330_b748000_132.ts

#EXTINF:1.072,

media_w1439163330_b748000_133.ts

#EXTINF:1.042,

media_w1439163330_b748000_134.ts

#EXTINF:9.085,

media_w1439163330_b748000_135.ts

2

Hello stevezm,

This issue could be caused by either a fluctuation in the framerate and/or keyframe of your source stream or the keyframe interval is set to something other than 1 second.

The chunk duration should be a multiple of the keyframe interval.

Check out this article to get the correct numbers set.

Regards,

Alex