Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
SUCCESS: UHD/4K DVB capture without compatible hardware
#1
Out of sheer curiosity I discovered the ability to capture UHD/4K DVB Streams with my 5 yr. old low cost linux receiver. Here is what happened:

Waiting for the CL match between Liv and ManCity yesterday evening, Sky repeatedly bombed its viewers with commercials for their UHD Sports Channels.
Having some unsorted ideas in mind I tuned into Sky Sports UHD just to see what happens. Of course the screen stayed black, but to my surprise sound was there!

OK, first conclusion:
- tuning into channel: OK
- CAM descrambling: OK
- DEMUX: OK
- decode audio: OK
- decode video: FAIL (of course!)
This was more than I expected.

Now, knowing that the stream recording on this receiver is done somewhere around the demuxing process, capturing this stream should work as it does with HD and SD streams. I set a timer for the first half of the game, and checked back during the half time intermission.
It worked! The stream opened and played in VLC, well, kind of - even my 2016 MBPro i7 QuadCore wasn’t able to play the stream somewhere near 50fps, maxing out all 4 cores at 100%.
I had no time to test other players yet, but I think without hardware acceleration I will be kind of lost on all of my machines.

I will follow up later with technical infos of the stream, screenshots and stream samples if possible.

Let’s hope Sky will launch a UHD movie channel in the near future.

d.
Reply
Thanks given by: spoRv , TomArrow
#2
Great stuff.
Makes sense it would work but I never would of thought to try it, Good work sir Smile
Reply
Thanks given by:
#3
I just managed to cut a 1:34min sample file with TSDoctor. It is Salah's goal for the 1:0 lead.
Below are the Media Infos, 4 Screenshots and links to the sample file as TS, MKV and MP4.
Please DL the samples and give me some feedback how the playback works on your machines or Smart TVs.

Media Info:
General
ID                                       : 187 (0xBB)
Complete name                            : Sky_Sport_UHD_Live_UEFA_CL__FC_Liverpool___Manchester_City.ts
Format                                   : MPEG-TS
File size                                : 331 MiB
Duration                                 : 1 min 34 s
Overall bit rate mode                    : Variable
Overall bit rate                         : 29.5 Mb/s

Video
ID                                       : 1535 (0x5FF)
Menu ID                                  : 1000 (0x3E8)
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main 10@L5.1@Main
Codec ID                                 : 36
Duration                                 : 1 min 34 s
Bit rate                                 : 27.8 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 50.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 10 bits
Bits/(Pixel*Frame)                       : 0.067
Stream size                              : 312 MiB (94%)

Audio #1
ID                                       : 1539 (0x603)
Menu ID                                  : 1000 (0x3E8)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Format settings, Endianness              : Big
Codec ID                                 : 6
Duration                                 : 1 min 34 s
Bit rate mode                            : Constant
Bit rate                                 : 192 kb/s
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 31.250 FPS (1536 spf)
Bit depth                                : 16 bits
Compression mode                         : Lossy
Delay relative to video                  : 127 ms
Stream size                              : 2.16 MiB (1%)
Language                                 : qab
Language, more info                      : Clean effects
Service kind                             : Complete Main

Audio #2
ID                                       : 1540 (0x604)
Menu ID                                  : 1000 (0x3E8)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Format settings, Endianness              : Big
Codec ID                                 : 6
Duration                                 : 1 min 34 s
Bit rate mode                            : Constant
Bit rate                                 : 96.0 kb/s
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 31.250 FPS (1536 spf)
Bit depth                                : 16 bits
Compression mode                         : Lossy
Delay relative to video                  : 287 ms
Stream size                              : 1.08 MiB (0%)
Language                                 : qac
Language, more info                      : Clean effects
Service kind                             : Complete Main

Screenshots:
[Image: Sky_Sport_UHD_Live_UEFA_CL_FC_Liverpool_...y_0004.jpg] [Image: Sky_Sport_UHD_Live_UEFA_CL_FC_Liverpool_...y_0005.jpg] [Image: Sky_Sport_UHD_Live_UEFA_CL_FC_Liverpool_...y_0002.jpg] [Image: Sky_Sport_UHD_Live_UEFA_CL_FC_Liverpool_...y_0003.jpg]

Samples:
Transport Stream
Matroska
MP4

@CSchmidlapp: In retrospective I ask myself - where did this idea suddenly come from... Tongue
Reply
Thanks given by: TomArrow
#4
Started downloading the .ts file and tried watching the unfinished download with MPC-HC. Ran kinda okay-ish. Sometimes there were artifacts on scene changes. Gotta try remuxing to mkv or mp4 once it's finished downloading.

The quality naturally is as bad as you would expect, considering the resolution, framerate and bitrate. Though I have to say it is watchable in 1080p (which my display is), even though it still looks hilariously smoothed.

All in all I think that a 1080p HDTV stream with the same bitrate will have a giant edge over this in terms of quality. Then again, this is a sports broadcast and they've always looked terrible/bitstarved. Would be curious how much bitrate they throw at feature films. Might start looking okay around 60-100 Mbps.

Thanks for sharing!
Reply
Thanks given by:
#5
@TomArrow: I agree, overall the quality is somehow disappointing, considering the available resolution.
I hardly doubt we will see any commercial channels with a bitrate >25Mbps in the near future. Bandwidth is money for cable providers and satellite owners and one UHD channel equals up to 4 HD channels.
Reply
Thanks given by:
#6
It's not new that you can capture stuff with Linux-receivers even though they're actually not capable of decoding the video. Back in 2008 I made a test-record of a World Cup-match on ORF1 HD with my old SD-Linux-receiver and it worked as well. That was the first time I saw a genuine HD-broadcast. Big Grin

What confuses me more is why you were able to descramble the German Sky UHD-programmes. I thought this was only possible with the Sky UHD-receiver as these channels usually don't work with Linux-softcams (like Sky 1 HD) and they don't offer these channels for customers with CI+ modules. At least it still doesn't work for me, just tried it again on Sky Bundesliga UHD. Wink
Reply
Thanks given by:
#7
@Dr. Cooper: Sky doesn't offer this for customers with CI+ modules via satellite, that is correct. But if you are a customer of Kabel Deutschland or Unitymedia, you can book the Sky package onto your cable providers smartcard, and they don't care a s**t about your receiver. Beyond that it is quite easy using oscam.
I recently also build a tvheadend server using the smartcard. Works like a charm.

P.S.: Links have been updated
Reply
Thanks given by: Dr. Cooper
#8
Alright, that makes sense. I'm a satellite-customer, so that's the reason I'm still only getting a dark screen on the UHD-channels. Well, why shouldn't the cable-customers also have at least one advantage if they have to step back with anything else although they're paying the same rates as satellite-customers. Wink
Reply
Thanks given by:


Possibly Related Threads…
Thread Author Replies Views Last Post
  [Help] Best video capture dongle for VHS to Mac Stamper 7 1,684 5 hours ago
Last Post: Stamper
  Sync problems during analog capture? BusterD 9 2,417 2020-10-01, 01:52 PM
Last Post: pipefan413
  Laserdisc PCM Capture Guide bronan 72 9,337 2020-09-21, 08:12 PM
Last Post: schorman
  Bit-perfect LD-capture - What's necessary? Dr. Cooper 29 5,041 2020-09-12, 03:31 AM
Last Post: pipefan413
Exclamation High-end video capture cards spoRv 91 36,236 2020-09-07, 03:38 AM
Last Post: zoidberg
  Laserdisc capture - general thread willie1959 49 17,444 2020-07-30, 09:54 AM
Last Post: spoRv
  Locations List of people willing to assist with bit-perfect LD audio capture jerryshadoe 36 17,752 2020-07-01, 04:26 AM
Last Post: BDgeek
  hardware for capturing Laserdisc video markosjal 10 1,900 2020-04-17, 08:42 PM
Last Post: bendermac
  Anyone have a way to capture AND record to VHS? TomArrow 0 876 2020-02-28, 09:47 PM
Last Post: TomArrow
Exclamation High-end audio capture cards spoRv 19 8,676 2019-07-17, 07:22 PM
Last Post: bronan

Forum Jump:


Users browsing this thread: 1 Guest(s)