Digilite and H264 work well together!

F6DZP
Posts: 217
Joined: Fri May 27, 2011 9:59 am

Re: Digilite and H264 work well together!

Post by F6DZP » Fri Apr 27, 2012 6:12 pm

Many questions...
1) coding
As I said, we can do it but it is not worth much to code HD1920x1080 in mpeg2 :
- if we want rate about 5Mbps we can but the picture is not very good ( many very little squares)
- if we want quality we must go to very high data rates.
I have tried with live video from my HDV camera using firewire input. It works with mpeg2 but I don't like the video quality.

one solution is to add a scaler filter that will reduce the video definition before coding.

2) Multiplexer and demultiplexer

some multiplexer are for PS , some other are for TS and some can be set to both modes.
some demultiplexer are for PS, others for TS and others for both...

about demultiplexers:
when you use one kind of demultiplexer, choice of Mpeg2 decoder can change many things ( MainConcept Mpeg2 decoder is very bad after a Cyberlink Mpeg splitter => jerky video)
Very often the best of all demultiplexer is the generik Windows "Mpeg2 demultiplexer"

about multiplexer:
I have made many tests last days with the Elecard multiplexer coming from Elecard SDK demo.
We can use it without any problem or restriction to produce TransportStream.

So I have made a solution this morning using only "free" directshow filters to produce H264 from my live video signal coming from my webcam HD Logitech C525
-for H264 encoding, I use the free ffdshow H264 coder we can find with the ffdshow package rev3631 ( latter versions have no more H264 coder)
-for TS encoding I use the Elecard muxer we can have for free if we install the Elecard SDK G4.
I send the result to Digilite Transmit (future version 2.0 under test) using the UDP and it works well.
For the moment I can have good result with Ffdshow H264 codec only for standard format (640x480 or 720x576) but have problem with HD format.

Perhaps ffdshow H264 codec can be enough for station that use SD resolution and need H264 for narrow bandwidth with better video quality than Mpeg2 give.


Jean Pierre F6DZP

M0DTS
Posts: 430
Joined: Sun Feb 24, 2008 9:03 pm

Re: Digilite and H264 work well together!

Post by M0DTS » Fri May 04, 2012 8:25 pm

Thanks for more tips...very useful, it's a shame the filters do not have a more exact description of their application.

After some thought i gave in and decided to upgrade my pc ...hi

Now able to encode 1920x1080 60fps to mpeg2 PS at 8Mb/s for testing, encoding speed is about 2.2x.

Now i have a new question! you are using ffdshow encoder to generate the h.264 video stream, how do i change the output settings for this?, it has no CBR or VBR just a fixed bit rate setting.
I tried to get some video encode output but no luck using ffdshow, so i started to use the Elecard's AVC h.264 encoder. This works quite well here sending a TS to digilite and excellent video quality in 1920x1080! nearly as good as BBC HD ;-)


The only problem with the TS is that none of the muxers we have give us the DVB configuration settings, still nice to see it work.

Now to find an intensity pro HDMI capture card so i can use my HD camcorder as the video source.....

73

Rob - making some progress!

Snapshot below is 8Mb/s (6Ms 7/8) of MPEG2, h.264 quality is even better using 5.5Mb/s (4Ms 7/8) - both 1920x1080
Attachments
vlcsnap-2012-05-04-21h23m41s240.png
vlcsnap-2012-05-04-21h23m41s240.png (845.04 KiB) Viewed 3894 times

F6DZP
Posts: 217
Joined: Fri May 27, 2011 9:59 am

Re: Digilite and H264 work well together!

Post by F6DZP » Sat May 05, 2012 8:02 pm

Hello,
Just to attach a .TS file
mire 1920x1080 H264 SR 466 kS.zip
(593.55 KiB) Downloaded 499 times
that show that we can have a good HD 1920x1080p moving picture with sound with only A SR of 466 kS.
Digilite Transmit seems not to go down less than 500 kS... I have used my DTA107 modulator to send that and Tutioune as receiver.
( and for the moment I have many resync problems with Digilite transmit when I use SR between 500 kS and 1000 kS)
A small file like that could be put in a little memory card...

If you cannot modulate this TS or receive it for the moment, you can look at it with VLC on your 1920x1080 LCD monitor.

Jean Pierre F6DZP

M0DTS
Posts: 430
Joined: Sun Feb 24, 2008 9:03 pm

Re: Digilite and H264 work well together!

Post by M0DTS » Sat May 12, 2012 1:27 pm

Discovered this earlier... seems to work well but has a demo logo in the middle even though it's free?

It does CBR MPEG2 and MPEG-4 (don't think H.264) and has optional built in muxer.

http://www.standardmpeg.com/

Rob
M0DTS

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