color artefacts on dvb-c channels, where to start troubleshooting?

Added by anderstvheadend olsen 5 months ago

examples of the issue is seen here https://imgur.com/a/249pTog

Using an beelink GT1 (amlogic s912) running a recent(maybe not latest) version of libreelec.
xbox one dvb-c/t/s dongle plugged into the beelink GT1.
the tvheadend server and frontend are both installed on the same device.
I have a fiber modem/gateway (Icotera i6800) outputting the unencrypted dvb-c signal, between the modem and dvb-c dongle is about 10 meters of RG6 cable.

The issue usually comes after a couple of minutes after changing to the channel and stays until I switch channels again.
Have only seen the issue on a few of the channels.
have not seen the issue when using the built in tuner in my TV.

hopefully someone can help me troubleshoot this issue.

edit: in case it is not obvious in the pictures, the artefacts are the colored bars that seem to be misplaced to the right of the object they belong to..


Replies (4)

RE: color artefacts on dvb-c channels, where to start troubleshooting? - Added by Vahram Mazlumyan about 1 month ago

hello

I have the same issue , did you solve problem ?

RE: color artefacts on dvb-c channels, where to start troubleshooting? - Added by saen acro about 1 month ago

To both can you share records of stream 5-10 min long for analyse.
I'm guessing operators use some cheap encoder or badly configured PC streamer
http://www.lighterra.com/papers/videoencodingh264/

this is from Chat with Vahram Mazlumyan

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Video_Format_WithHint_List               : AVC
Codecs Video                             : AVC
Audio_Format_List                        : MPEG Audio
Audio_Format_WithHint_List               : MPEG Audio
Audio codecs                             : MPEG-1 Audio layer 2
Menu_Format_List                         : AVC / MPEG Audio
Menu_Format_WithHint_List                : AVC / MPEG Audio
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File name                                : vlc-record-2018-07-06-14h19m38s-ArmNews24-
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Codec                                    : MPEG-TS
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File size                                : 52 MiB
File size                                : 52 MiB
File size                                : 52.1 MiB
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Duration                                 : 1 min 12 s 102 ms
Duration                                 : 1 min 12 s
Duration                                 : 00:01:12.102
Duration                                 : 00:01:12:01
Duration                                 : 00:01:12.102 (00:01:12:01)
Overall bit rate mode                    : VBR
Overall bit rate mode                    : Variable
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Overall bit rate                         : 6 051 kb/s
Frame rate                               : 25.000
Frame rate                               : 25.000 FPS
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Stream size                              : 2832080
Stream size                              : 2.70 MiB (5%)
Stream size                              : 3 MiB
Stream size                              : 2.7 MiB
Stream size                              : 2.70 MiB
Stream size                              : 2.701 MiB
Stream size                              : 2.70 MiB (5%)
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File creation date                       : UTC 2018-07-06 10:36:31.428
File creation date (local)               : 2018-07-06 13:36:31.428
File last modification date              : UTC 2018-07-06 10:36:42.521
File last modification date (local)      : 2018-07-06 13:36:42.521
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Video
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Format profile                           : [email protected]
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Format settings, CABAC                   : Yes
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 2
Format settings, RefFrames               : 2 frames
Format settings, GOP                     : M=3, N=15
Internet media type                      : video/H264
Codec ID                                 : 27
Codec                                    : AVC
Codec                                    : AVC
Codec/Family                             : AVC
Codec/Info                               : Advanced Video Codec
Codec/Url                                : http://developers.videolan.org/x264.html
Codec profile                            : [email protected]
Codec settings                           : CABAC / 2 Ref Frames
Codec settings, CABAC                    : Yes
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Duration                                 : 72040
Duration                                 : 1 min 12 s
Duration                                 : 1 min 12 s 40 ms
Duration                                 : 1 min 12 s
Duration                                 : 00:01:12.040
Duration                                 : 00:01:12:01
Duration                                 : 00:01:12.040 (00:01:12:01)
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Bit rate                                 : 5 493 kb/s
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Height                                   : 1080
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Sampled_Width                            : 1920
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Frame rate                               : 25.000
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Scan order                               : Top Field First
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Interlacement                            : MBAFF
Bits/(Pixel*Frame)                       : 0.106
Delay                                    : 15906218.000
Delay                                    : 4 h 25 min
Delay                                    : 4 h 25 min 6 s 218 ms
Delay                                    : 4 h 25 min
Delay                                    : 04:25:06.218
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Stream size                              : 47 MiB
Stream size                              : 47 MiB
Stream size                              : 47.2 MiB
Stream size                              : 47.18 MiB
Stream size                              : 47.2 MiB (91%)
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Audio
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ID                                       : 1026 (0x402)
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Format profile                           : Layer 2
Internet media type                      : audio/mpeg
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Duration                                 : 1 min 12 s
Duration                                 : 1 min 12 s 96 ms
Duration                                 : 1 min 12 s
Duration                                 : 00:01:12.096
Duration                                 : 00:01:11:22
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Bit rate                                 : 256 kb/s
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Sampling rate                            : 48.0 kHz
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Frame rate                               : 41.667 FPS (1152 SPF)
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Stream size                              : 2 MiB
Stream size                              : 2.2 MiB
Stream size                              : 2.20 MiB
Stream size                              : 2.200 MiB
Stream size                              : 2.20 MiB (4%)
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Codec                                    : AVC / MPA1L2
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List                                     : 1025 / 1026
List                                     : 1025 (0x401) (AVC) / 1026 (0x402) (MPEG Audio)

RE: color artefacts on dvb-c channels, where to start troubleshooting? - Added by Em Smith about 1 month ago

You say frontend is on the same machine, so I'm guessing that is Kodi. I'm not sure if you can see the tvheadend logfile on the box to see if it logs any errors about overflows while recording.

I would install Kodi on a laptop, enable Kodi's tvheadend PVR (remember to change IP address in its config to whatever the backend is). Then play a recording that fails on your tv. Does it work on your laptop without artefacts? If so, it's likely to be a Kodi issue on the S912.

If it fails, then I'd connect a USB keyboard up to the S912. Play a recording on S912 and press "Ctrl-Shift-O" (IIRC) (that's the letter O) to call up detailed information on the playback such as bitrate. Does it fail only on channels with a "high" bitrate?

IME, the xbox tuner is good for the price but requires a stronger tv signal than my other tuners, and my computer tuners all require a stronger signal than my tv. So you could always try moving the box right next to your signal without the 10m cable and see if that solves anything.

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