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#EXT-X-PROGRAM-DATE-TIME may be wrong

After starting my transcoder and push rtmp audio stream, my fastly target’s playback url returns like

[I] ➜ http https://cdn3.wowza.com/1/xxxxx/yyyyy/hls/live/playlist.m3u8
HTTP/1.1 200 OK
...
Content-Length: 110
Content-Type: application/x-mpegURL
Date: Fri, 17 Jul 2020 08:28:34 GMT
Via: 1.1 varnish
X-Cache: MISS
X-Cache-Hits: 0
X-Served-By: cache-tyo19920-TYO
X-Timer: S1594974515.832076,VS0,VE78

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-STREAM-INF:BANDWIDTH=67021,CODECS="mp4a.40.2"
../jfpdkl28/1/chunklist_ao.m3u8

It’s fine. But looking into chunklist_ao.m3u8…

[I] ➜ http https://cdn3.wowza.com/1/xxxxx/yyyyy/hls/jfpdkl28/1/chunklist_ao.m3u8
HTTP/1.1 200 OK
...
Content-Length: 559
Content-Type: application/x-mpegURL
Date: Fri, 17 Jul 2020 08:28:37 GMT
Via: 1.1 varnish
X-Cache: MISS
X-Cache-Hits: 0
X-Served-By: cache-tyo19933-TYO
X-Timer: S1594974517.336859,VS0,VE279

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-DISCONTINUITY-SEQUENCE:0
#EXT-X-TARGETDURATION:11
#EXT-X-MEDIA-SEQUENCE:7
#EXT-X-PROGRAM-DATE-TIME:2020-07-17T08:27:54.671Z
#EXTINF:10.031,
0001ah19/media_ao_7.aac
#EXTINF:10.031,
0001ah19/media_ao_8.aac
...
#EXTINF:9.961,
0001ah19/media_ao_15.aac
#EXTINF:10.031,
0001ah19/media_ao_16.aac

#EXT-X-PROGRAM-DATE-TIME may be a little old. And next updates,

[I] ➜ http https://cdn3.wowza.com/1/xxxxx/yyyyy/hls/jfpdkl28/1/chunklist_ao.m3u8
HTTP/1.1 200 OK
...
Content-Length: 560
Content-Type: application/x-mpegURL
Date: Fri, 17 Jul 2020 08:28:53 GMT
Via: 1.1 varnish
X-Cache: HIT
X-Cache-Hits: 1
X-Served-By: cache-tyo19933-TYO
X-Timer: S1594974533.035981,VS0,VE1

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-DISCONTINUITY-SEQUENCE:0
#EXT-X-TARGETDURATION:11
#EXT-X-MEDIA-SEQUENCE:8
#EXT-X-PROGRAM-DATE-TIME:2020-07-17T08:28:14.733Z
#EXTINF:10.031,
0001ah19/media_ao_8.aac
#EXTINF:9.961,
0001ah19/media_ao_9.aac
...
#EXTINF:10.031,
0001ah19/media_ao_16.aac
#EXTINF:10.031,
0001ah19/media_ao_17.aac

One sequence proceeds, and #EXT-X-PROGRAM-DATE-TIME increases 20secs although #EXT-X-TARGETDURATION is 11.

some minutes later…

[I] ➜ http https://cdn3.wowza.com/1/xxxxx/yyyyy/hls/jfpdkl28/1/chunklist_ao.m3u8
HTTP/1.1 200 OK
...
Content-Length: 562
Content-Type: application/x-mpegURL
Date: Fri, 17 Jul 2020 08:34:30 GMT
Via: 1.1 varnish
X-Cache: MISS
X-Cache-Hits: 0
X-Served-By: cache-tyo19940-TYO
X-Timer: S1594974871.676711,VS0,VE156

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-DISCONTINUITY-SEQUENCE:0
#EXT-X-TARGETDURATION:11
#EXT-X-MEDIA-SEQUENCE:42
#EXT-X-PROGRAM-DATE-TIME:2020-07-17T08:39:34.753Z
#EXTINF:9.961,
0001ah19/media_ao_42.aac
#EXTINF:10.031,
0001ah19/media_ao_43.aac
...
#EXTINF:10.031,
0001ah19/media_ao_50.aac
#EXTINF:9.962,
0001ah19/media_ao_51.aac

Now, #EXT-X-PROGRAM-DATE-TIME is absolutely in future. I doubt something wrong with my transcoder or output settings… How this behavior occurs?

Also, I can’t determine if this is the reason, but Android Exoplayer can’t play well our transcoder’s output (It stops playing after some time)

I’ll need to check on how compatible Exoplayer’s libraries are with cloud transcoder and fastly.

This is definitely not something we would be able to do as far as timestamps for the future segments. I’d submit a support ticket so we can see what is going on here. We may need to test with the Android Exoplayer and the timestamps.