Slow DVB-T channel switching

[voochi]

Hi,
I am using VLC 2.15 x64 on Win 8.1 with a Augist DVB-T205 tuner.

If I operate my tuner in the simplest way - Open Capture Device > TV Digital > *manually enter freq and bandwidth* then everything works fine. After a couple of seconds the program list is populated and channel switching is almost instant.

However if I try to create a playlist like so:

Code: Select all

<?xml version="1.0" encoding="UTF-8"?> <playlist xmlns="http://xspf.org/ns/0/" xmlns:vlc="http://www.videolan.org/vlc/playlist/ns/0/" version="1"> <title>Saorview</title> <trackList> <track> <title>RTE 2</title> <location>dvb-t://frequency=546000000:bandwidth=8</location> <extension application="http://www.videolan.org/vlc/playlist/0"> <vlc:id>0</vlc:id> <vlc:option>dvb-adapter=0</vlc:option> <vlc:option>program=1103</vlc:option> <vlc:option>live-caching=300</vlc:option> </extension> </track> <track> <title>TV3</title> <location>dvb-t://frequency=546000000:bandwidth=8</location> <extension application="http://www.videolan.org/vlc/playlist/0"> <vlc:id>1</vlc:id> <vlc:option>dvb-adapter=0</vlc:option> <vlc:option>program=1104</vlc:option> <vlc:option>live-caching=300</vlc:option> </extension> </track> </trackList> <extension application="http://www.videolan.org/vlc/playlist/0"> <vlc:item tid="0"/> </extension> </playlist>

then channel switching is very slow, like 5s each time.

Any ideas? Am I doing something wrong?

Thanks

[MichaelMc]

You're doing noting wrong as that's precisely how I'm also using it, but with only ~1second delay between playlist entry 'start/stop/start,etc..'. ~1 second is acceptable (for me) and i'm using 2.0.3.
Just posting really to inform you that there is a 4 thread 'thread leak' per playlist stop/start when using VLC in this manner with DVB-t with every VLC version from 2.0 right through to 3.x. Just something I thought you might want to be aware off.

5 seconds is a little long but I did notice that with vlc 2.2 each dvb stream oddly begins with a blocky grey screen for a few seconds.

[voochi]

Thanks for the reply.

I timed it to pretty much 5 seconds. The current channel pauses, it waits for a second, then a black screen with the VLC icon shows briefly and finally the new channel starts to play.

With the manual method takes a few seconds to initially get started, but once the program list is populated, switching is pretty much instant. Like 0.5s or less.

The only thing I can think is that when switching channels via the playlist method, maybe it is re-initializing the tuner every time? And needs to figure out the technical details (QAM, guard interval etc). Should I put all the technical details (guard interval etc) in the playlist for each channel?

[MichaelMc]

I believe the delay could be related to the destroying and recreating of the directshow filter graph per playlist selection. Doesn't really help you much other than entering technical details doesn't and hasn't reduced this for me, and I've used several USB DVB-t tuners.
Mediaplayer classic HC is much more configurable in this regard, filter graphs and all that stuff which you could try, but imo nothing beats VLC from a user experience point of view.

fyi: I use the Belfast Divis transmitter.

[voochi]

It did not even occur to me that MPC-HC had dvb-t capability. I tried it and it's perfect, thanks.