Posts Tagged ‘transport stream’

Capturing and archiving of DVB-T signal

Saturday, May 28th, 2011

No matter if it’s for compliance recording so you will capture and save your own broadcast, or you are doing media monitoring and you would like to capture multiple signals of the air, you have some interesting choices here.

Let’s explore in detail your options on the subject, whether it’s one channel or multiple channel recording.

One channel DVB-T recorder

Recording of one channel is simple no matter how you choose to record it. Let me present two main options here for you, so you could see what is most applicable in your situation.

Simplest way of recording would be to have one set top box for DVB-T, and use it to send composite signal into the computer via the Osprey 210 card. It is the most robust solution, but it has some (serious) drawbacks:

  • cheap DVB-T tuners can ‘lock’ and freeze the picture
  • low quality tuners can also de-sync audio and video with time – and you need 24/7 operation here
  • you’ll need extra power connector for the set top box
  • STB-s are producing extra heat

Alternative way of recording is to use DVB-T card such as Asus MyCinema-ES3-110, use software such as TubeSink to tune on a frequency and extract the channel required from it (this is called DEMUX-ing) and forward the extracted channel to the VideoPhill Recorder for further processing (recording, streaming, …).

BTW, TubeSink mentioned above can be used even without VideoPhill Recorder, as it DEMUXes the channels and can forward them to any computer on your network as an UDP Transport Stream that can be playable with VLC. Nike Air Max 2017 Heren grijs It you want to use it for non-commercial purposes, download it from here.

So in the case on 1 channel DVB-T recording, I would say that it remains uncertain whether to use external set top box with Osprey capture card, or go with pure software solution and some simple of-the-shelf DVB-T tuner.

But in case of…

Multiple channels DVB-T recording facility

Same options are available at multiple channel recording facilities – but here is the catch. As you might probably know, multiple DVB-T channels are packed and are transmitted at one frequency and that is called multiplexing. The carrier for the channels that are transmitted is called MULTIPLEX (MUX for short). nike air max 2017 pas cher In several occasions it has 4 channels, and sometimes it can have as much as 16 or more channels.

Current recommended recorder density (channels per machine) is 4. Adidas Gazelle Heren One machine packed with Osprey 460e will do 4 channels just fine.

So, let’s say that we need 16 channels and they are scattered across 3 MUX-es (we have such situation here in Zagreb). Using a conventional method (I would say that having 16 STBs is conventional, as bizarre as it seems) you’ll need the:

  • 4 recording servers
  • 4 Osprey 460e cards
  • 16 DVB-T set top boxes
  • PLENTY of mains outlets
  • some kind of distribution to have the signal distributed to all 16STBs

Since you see where I’m coming to, let me suggest the following; let’s use TubeSink to control 3 tuners in TWO MACHINEs, and save on 4 Ospreys and 2 PCs, and the rest of the unnecessary equipment.

We’ll put 2 tuners into one machine, and one tuner in the second machine. kanken fjallraven If the channel per MUX distribution is such that each machine has it’s 8 channels, fine. Nike Air Huarache Heren If not, we’ll instruct TubeSink to forward the Transport Stream to ANOTHER machine and that machine will perform recording. In that way, load will be completely balanced between two machines, and you’ll have your 16 channels recorder in a nice and compact fashion.

Even more compact?

Yes, it can go even further. There are dual DVB-T tuners such as WinTV-HVR-2200 that can provide tuning to two frequencies at once, and with it, you could record as much channels there are in two MUXes at one machine. Nike Air Max 2017 Homme Today, even desktop processors such as i7 can encode 8 channels of video in real time. So, with proper CPU (or multiple CPUs on server computers) – even 16 channels could be encoded in one compact 2U rack mounted unit.

However… (serious problem)

Using PC based DVB-T cards will only work with free to air channels.