Tvheadend

Hello,

I am currently using the unstable release for Debian Stretch (HTS Tvheadend 4.3-1804~gebb096804).
This issue is derived from https://tvheadend.org/boards/4/topics/38259?r=38461#message-38461.

I added some DVB-T channels which have "embedded" Electronic Program Guide, and I also configured an additional grabber so that I can use the information provided by an external XMLTV file.
All seems to load and work properly, and seems to be accurately displayed in the Electronic Program Guide tab of the Tvheadend web interface.

However, the EPG of most IPTV channels is not shown when playing the generated list of HTTP streams (via http://tvh.ip:9981/playlist) in VLC even after minutes of playing a particular stream. Only one or two IPTV channels (which already have "embedded" EPG in the stream) are displayed correctly. The issue is present also for SAT>IP clients.
The EPG displays correctly for DVB-T channels.

My questions regarding this issue are:
1. What are the means to "integrate" or "embed" the EPG in the HTTP (MPEG-TS?) streams for the IPTV channels which do not have it?
2. Are such tools already integrated in Tvheadend and if yes, how can one configure them?
3. If there are no such tools, how can they be implemented and integrated?

I suppose that the EPG is contained in some kind of tables, e.g., the Service Description Table (SDT) and Event Information Table (EIT) from the DVB standards.

From what I already found, some software which could perform such tasks would be openepg and opencaster, perhaps also libdvbtee.

Any help would be greatly appreciated.
Thank you in advance!