Live TV channel switching is very slow

[george 0]

Hi 

Recently I re-formatted my HTPC (i5-4200U) and I installed win 10 clear.

Now I re-installed the emby but in the latest versions the channel switching became really slow

I think it takes more than 12 seconds to change channel while in one of the old versions that I was using

i.e 3.0.5641.4 the channel switching was fast.

I read somewhere that this is due to the ffmpeg because it takes time to analyze the frame.

Is there a way to make the channel switching faster with the new version of ffmpeg

For example the broadcasting stations dont change their format and we can save this information

and to guide ffmpeg to use those saved settings for each channel instead of re-analyzing the channel everytime

we select it. Of course that was an idea.

 

Another problem that I have is that the stream at 720Kbit is not that stable as before. the stream is getting interrupted 

for a second or two. I never had this problem with the old version. ( I tested multiple times in order to exclude internet variance).

 

Finally I am a bit confused about the playback-streaming-Internet streaming bitrate limit (Mbps): option

 As soon as select 0.75Mbit streaming the stream becomes unstable. Actually all other streaming settings are ignored

by checking my router's speed I see that the ffmpeg does produce constant bitrate it does not justified those "breaks"

at 720Kbit. 

At last and maybe this is my personal request to the developers if you can add custom bitrates instead of the predefined ones.

I stream TV using my ADSL connection where the upload speed is 1024Kbits. I would like to setup bitrates at 900 or 950 Kbits

in order to get the best picture

 

 

PS. Actually I take it back. ffmpeg does not produce constant bitrate. Even through I have selected 720Kbit I see my incoming traffic varies from 700-1200Kbit

If my router's incoming traffic is true then the stream is throttle because of the connections (my max upload is 1024K and I use it only for TV)

Edited October 29, 2015 by george

[Luke 37024]

what tv provider are you using? the built in one or a plugin?

 

what do you mean by 

does not justified those "breaks"

? Thanks.

[george 0]

Hi Luke. I have two DVB-T2 tuners triple from PCTV and I use nextPVR and the plugin.

The breaks are actually stops during watching a channel

[Sven 136]

Hi Luke. I have two DVB-T2 tuners triple from PCTV and I use nextPVR and the plugin.

The breaks are actually stops during watching a channel

 

I know that it's slow to load a new live stream. 

 

 

When I test it it takes many time to create the output file we use in emby. I already asked on some forums for help.

But those things didn't work yet....

[george 0]

Hi Sven

 

Is this something has to do with the new ffmpeg or it is the way we handle the streams?

We know the stream properties from the tuners and if we dont know them

we can easily let ffmpeg to identify them once and then to save the properties of the stream

so the second time it will be faster without ffmpeg trying to identify the stream.

Also I noticed that transcoded stream fluctuates quite a lot. I select SD 720Kbits and I check

my router's traffic and I see that it goes way higher that then (for few seconds).

I believe the stream should be in a constant rate.

I remember the same thing was happening in a previous release but then suddenly in one update that issue

was fixed and the transcoded stream was constant

[Sven 136]

Hi Sven

 

Is this something has to do with the new ffmpeg or it is the way we handle the streams?

We know the stream properties from the tuners and if we dont know them

we can easily let ffmpeg to identify them once and then to save the properties of the stream

so the second time it will be faster without ffmpeg trying to identify the stream.

Also I noticed that transcoded stream fluctuates quite a lot. I select SD 720Kbits and I check

my router's traffic and I see that it goes way higher that then (for few seconds).

I believe the stream should be in a constant rate.

I remember the same thing was happening in a previous release but then suddenly in one update that issue

was fixed and the transcoded stream was constant

 

It was always slow. 

They are telling me to change some parameters but those ones didn't help...

 

You can also see my post on stackoverflow....

If you know something about ffmpeg....

Feel free to help.

 

http://stackoverflow.com/questions/33309776/ffmpeg-create-ouput-file-takes-20-seconds

[george 0]

I will take a look. 

Maybe it is about time to see all these parameters of ffmpeg

I use the TVCenter from the PCTV systems because my tuners are from PCTV and they use ffmpeg 

on their software. The channel switching is very fast and the bitrate it is very constant. 

I have a really good picture at the 700Kbits. 

Do you know how to create my custom bitrate profile instead of the predefined ones

[mshollack 0]

Having same problem. Taking 20 sec to change channels. Using hdhome extend with transcoding built into tuner. Using native built in DVR functionality on current release. Any ideas?

[Luke 37024]

Having same problem. Taking 20 sec to change channels. Using hdhome extend with transcoding built into tuner. Using native built in DVR functionality on current release. Any ideas?

 

It really depends on the app you use and whether it can direct play the format of the live tv broadcast. If it can, such as android mobile for example, then you can expect fast start times. Other devices such as web browsers have only limited format support. When your TV broadcast doesn't match the device's supported formats, we have to use a process called transcoding to convert it on the fly. You can learn more about that in our wiki here:

 

https://github.com/M...iki/Transcoding

 

Of interest to you might be the section titled

Why Is My Media Transcoding?

[mshollack 0]

Thanks for the quick reply and links. I will read up on those topics. I'm using the Amazon TV and new IOS app but on occasion do use the web interface. The first two seem only marginally faster.