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DVBViewer does not show the video feed properly


Elnur Hajiyev

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I encountered an issue today while trying to view DVB-S2 channels from a specific transponder on DVBViewer Pro. Video frames do not update in the viewer screen unless there is an interaction with it(hovering the cursor on the control buttons, entering/exiting the full screen mode). Basically I see frozen frames when I try to watch an affected channel. Same channels worked perfectly few hours ago though.

 

I have restarted DVBViewer Media Server and it did not resolve the issue.

 

Note: This only happens in DVBViewer Pro. Other clients(TBSViewer) shows the video without an issue for the same channels in the same time period.

 

I am adding the logs and the transponder details below:

 

Frequency: 11024 MHz

Polarization: V

Symbol Rate: 12700 kS/s

FEC: 5/6

 

Receiver: TBS6903-X (2.0.0.3)

GPU: EVGA GTX670 FTW

support.zip

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Maybe the timing of those channels is a bit tight, so that frames are arriving too late (after their intended presentation time). Video renderers tend to drop such frames.

 

For diagnosis try to use Settings -> Options -> Playback Components -> Video -> Video Renderer -> EVR Enhanced Video Renderer (that is more tolerant) instead of EVR Custom Video Renderer.

 

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Also how do you think, is it most likely issue with the transponder or with the receiver or the LNB I have? Can I improve the timings from my end by switching to better equipments?

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vor 3 Stunden schrieb Elnur Hajiyev:

Where can I find a documentation on the available renderers and see which one is better suited in which condition.

 

Usually the EVR Custom Video Renderer is the best for DVBViewer, because it is customised and optimised for the DVBViewer OSD (On Screen Display) output.

 

The EVR Enhanced Video Renderer is ok, but since it is a Windows standard component that is not adjusted to DVBViewer needs you may encounter OSD issues in certain (rather rare) situations, particularly if a video stream is stopped for reasons outside DVBViewer (e.g. due to signal loss). In this case the OSD will not respond to user input anymore, unless you stop or pause video manually.

 

Video enthusiasts and experts may want to try the high quality MadVR renderer, that is well supported in DVBViewer. It must be installed before you can select it for video output. Please note that it requires more GPU (Graphics Processing Unit) power than other video renderers.

 

Forget about the rest - these are old legacy video renderers that (since Windows Vista) don't support hardware accelerated decoding anymore. They are only of interest for those who are still using Windows XP - some DVBViewer users really do!

 

vor 2 Stunden schrieb Elnur Hajiyev:

is it most likely issue with the transponder or with the receiver or the LNB I have?

 

It's due to the broadcaster, as I can see in your video. I'll provide more information later. It's difficult to explain, because it requires some knowledge about DVB technique.

 

 

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Am 24.2.2023 um 11:25 schrieb Griga:

Maybe the timing of those channels is a bit tight,

 

The broadcasted timing information can be viewed on the DVBViewer Property Page. For your video it looks like this:

 

Zwischenablage01.png

 

Please note that "DVB" is checked for letting the property page display the incoming time stamps, as they are broadcasted. PCR is the Program Clock Reference. It is the time base of your broadcaster, derived from a 27 MHz clock generator. It is not a "wall clock time" meant for humans. All other broadcasted timing information must be regarded in relation to the PCR. You can see here that the video PTS (Presentation Time Stamp) is approximately 220 milliseconds ahead. This means, the arriving video data shall be displayed in 220 ms. Or with other words, it must be processed completely within 220 ms. If it takes longer, the video frame is late.

 

220 ms seems to be quite a lot in a fast PC, but in your case it isn't sufficient for a live stream. It has to be considered that video frames are not necessarily broadcasted in the same order as they are displayed. The broadcaster's video encoder may change the order for achieving a better compression rate. This means, a certain number of video frames have to queue up in the renderer and to be re-sorted, before they can be displayed in the correct order. Besides other buffering and video decoding this also takes time.

 

The "Latency" value (by default 350 ms) indicates how much the DVBViewer Filter shifts video and audio time stamps towards the future when it transforms them to the time base of the Windows DirectShow stream time. Even that is not enough in your case. However, you can change this value e.g. to 1000 or even 2000 ms and try, if this "time shift" enables playing the channels with the EVR Custom video renderer. It grants the playback engine more time for video and audio processing. Please note that after a change you have to click "Apply" and then "Playback -> Rebuild Playback" in the DVBViewer main window for letting it take effect. The downsides of an increased latency value are a delayed playback start and more memory required for buffering.

 

For comparison, the output for a German satellite channel:

 

Zwischenablage02.png

 

Here video data arrives more than 1000 ms ahead, so there is much more time for processing the incoming video frames, resulting in more buffering (see "Queued Video Buffers" value), so it's much less likely that video frames become too late. This works with the EVR Custom renderer.

 

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  • 3 weeks later...

I got a similar problem with some new channels on TVRO in Brazil. Video is jittering and there is no audio. PMT says that the PCR is in the video stream but i'm not sure if it's there anyway because DVBViewer shows a very strange PCR clock.

 

Some STB can correctly decode these channels, others don't. On PC i've tried use othe EVR render but no luck. Is there any way to watch them?

 

CapturarDVB1.PNG.56f285beaf38c0645456e23e531d801f.PNG

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vor 16 Stunden schrieb micaelsilva:

PMT says that the PCR is in the video stream but i'm not sure if it's there anyway because DVBViewer shows a very strange PCR clock.

 

The PCR (Program Clock Reference) and the Video/Audio PTS (Presentation Time Stamps) don't match. The PCR is the broadcasters's clock (actually the output of a 27 MHz clock generator). The PTS must be regarded in relation to the PCR. They indicate when the arriving Video/Audio shall be played.

 

In your case the PCR is more than 11 hours ahead, indicating that Video/Audio should have been played 11 hours ago. Time discrepancies like this are usually deadly for playback. It could probably be played if DVBViewer would ignore the PCR and use the Audio PTS as substitute. Unfortunately this option is only available for the TS Stream reception type (Internet TV/Radio).

 

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Indeed it works that way, i've tried using Transedit to stream to HTTP and tunning in on DVBViewer with Remove clock reference active.

Although not a good way but at least it's a way.

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