Tout ce qu'il faut savoir pour bien gérer le traitement multimédia sur PC

acquisition DV, codage Mpeg2, multiplexage et modulation DVB

Messagede F6DZP » Mar 28 Déc 2010 18:43

Je repars sur le même graphe que le chapitre précédent pour coder la vidéo en Mpeg2 et l'audio en Mpegaudio
ensuite je vais multiplexer les 2 signaux en un seul pour obtenir mon flux TransportStream.
Il me restera ensuite à envoyer le flux TS dans ma carte de modulation (Transport Renderer)
(pour cette dernière opération il faut bien sûr le modulateur et son filtre)
DV to DTA107 SR6000 capture et codage.jpg
DV to DTA107 SR6000 capture et codage.jpg (109.82 Kio) Vu 23366 fois

DV to DTA107 SR6000 codage et mux.jpg
DV to DTA107 SR6000 codage et mux.jpg (80.39 Kio) Vu 23366 fois

DV to DTA107 SR6000 mux et modulatiion.jpg
DV to DTA107 SR6000 mux et modulatiion.jpg (78.81 Kio) Vu 23366 fois


en cliquant sur lecture on diffuse en DVB avec sa carte de modulation, on est en émission!

Ne pas hésiter à faire un clic droit sur chaque filtre puis sur chaque pin pour avoir les infos ou les réglages.


Pour les réglages de chaque filtre voici des exemples:
réglage codeur MPEG21.jpg
Réglage du codeur Mpeg2. On remarquera que l'on choisit le mode débit "constant" (= CBR), simple passe, Bit rate 6000 kb/s et que le GOP est de 12 avec 2 B-frames. On a aussi choist le mode 16/9 qui sera automatiquement détecté à la réception (surtout si c'est avec un PC)
réglage codeur MPEG21.jpg (106.91 Kio) Vu 23365 fois

réglage muxeur MPEG.jpg
Réglage du multiplexeur. J'ai mis 8 294 118 correspondant à un SR de 6000kS/s. On voit aussi les PID 1001 et 1002 pour l'audio et la vidéo etc, mais ces derniers points ont peu d'importance étant donné qu'un récepteur intelligent trouve les PID tout seul
réglage muxeur MPEG.jpg (93.77 Kio) Vu 23365 fois

réglage modulateur DTA107.jpg
Ici on voit que j'ai remis 8294118 pour un SR6000KS/s, la fréquence 1270 Mhz le mode de modulation : QPSK avec Fec 3/4. La carte de modulation utilisée est une Dektec DTA-107
réglage modulateur DTA107.jpg (67.27 Kio) Vu 23365 fois


"en cliquant sur lecture on diffuse en DVB avec sa carte de modulation, on est en émission!"
Nota :OUI MAIS : quel équipement?
Le mieux : la solution OM DATV live à partir de l'USB
sinon une carte de modulation pour PC du commerce
( dommage j'ai annoncé sur la liste ATV en mai 2010 que j' avais une source qui permettait d'acquérir des cartes de modulation pro autour de 500 euros
si on était assez nombreux mais trop peu de personnes se sont portées acquéreuses...
j'espère une bonne nouvelle de ce type pour 2011)

Avoir une carte fabrication OM ou du commerce branchée à son PC permet tout de suite de choisir toutes les sources dont on dispose, de coder en Mpeg2 ou H264,
de faire de la Simple Définition ou de la Haute Définition, de la 3D etc sans avoir besoin de dépenser autre chose pour son émission.
Grâce au PC on choisit son codage, son format etc.. et c'est très simple avec un graphe!
F6DZP
 
Messages: 665
Inscription: 24 Déc 2010

Re: acquisition DV, codage Mpeg2, multiplexage et modulation

Messagede W8KHP » Mar 6 Sep 2011 17:09

Hi Pierre,

I am having some problems I hope you can help me solve. I am trying to get
live output from a camera to a DTA-107. I have looked at your examples and
tried things that I thought should work but am not having any luck. I have
two potential cameras to use: Sony DCR-TRV340 and Logitech webcam. I would
prefer using the Sony but at this point would like to see anything work. In
the computer with the DTA-107 board I also have a Hauppauge PVR-150. I have
tried using the Sony through the PVR-150 and also directly streaming through
USB. In Graphedit I have the following video capture sources:
Hauppauge WinTV PVR PCI II Capture
Logitech QuickCam E2500
Sony Digital Imaging Video
In addition I have the following:
Hauppauge WinTV PVR PCI II Crossbar
Hauppauge WinTV PVR PCI II Encoder
Elecard MPEG Demultiplexer
Elecard MPEG Multiplexer
Elecard MPEG Push Demultiplexer
Elecard MPEG-2 Video Encoder HD
Elecard MPEG-2 Video Decoder HD
Trilogic MPEG-2 Transport Dektec Renderer
I have played with these in different combinations and nothing seems to
work. Can you please suggest what chain of filters might work. The Trilogic
MPEG-2 Transport Dektec Renderer never comes up with the second tab Mpeg-2
Transport that I see in your example. Also whenever I right click on the
renderer and then click on OK or apply I get the message "Cannot init Dektec
output!" The DTA-107 works just fine when I use Streamexpress and an
existing TS file.
I sincerely hope that you see an obvious solution to my problem.

Thank you very much.

73,
Al W8KHP
W8KHP
 
Messages: 2
Inscription: 23 Juin 2011

Re: acquisition DV, codage Mpeg2, multiplexage et modulation

Messagede F6DZP » Mer 7 Sep 2011 06:12

Hello,
It's not easy to answer in one or two sentences and to know exactly at what stage of procedure you have a problem.
I 'll take time to prepare a complete explanation with screen captures to show how to proceed to find what doesn't work.
Almost all of you video sources are usable in real time with DTA107 ( just 1 question about webcam that must give real 30 fps, not all webcam can do)

Try firstly with the Sony camera that musk work without problem.

You must proceed in different steps with Graphedit:

1- video and audio capture --> renderer

right click on the video renderer and look at proprietaries
put this filter: Sony Digital Imaging Video, right click and ask renderer,
play it to see that it works.
during playing, right click on the video renderer and look at proprietaries: fps and jitter (ms)
fps must be near 30 fps and jitter few ms


2- video and audio capture --> Mpeg2 coding --> Mpeg2 decoding -->renderer

just delete from precedent graph the video renderer and audio renderer.
you have now the video and audio ouput pins that must be coded with an Mpeg2 video encoder and Mpeg audio encoder.
you must tune wright all different coder parameters similarly with mine( main profil ...., CBR ...)
you right click at the output and ask for render
Graphedit will add of video decoder and video renderer /audio decoder and renderer
play it to see that it works.
during playing, right click on the video renderer and look at proprietaries: fps and jitter (ms)
fps must be near 30 fps and jitter few ms ( little more than first try)

3- video and audio capture --> Mpeg2 coding --> --multiplexing --> demultiplexing --> decoding -->rendererer

just delete from precedent graph the video Mpeg2 decoder+video renderer and mpeg audio decoder +audio renderer.
you have now the an Mpeg2 video encoder and Mpeg audio encoder pins. ask for a multiplexer.
set parameters with wright values ( you must compute a global rate value corresponding to the SR/fec you will use - for SR4000 fec3/4 we must write 5529412, this value must be about 5 to 10% higher than mpeg2 video rate + mpeg audio rate - use padding to complete with null packets)
you right click at the multiplexer output and ask for render
graphedit will add a demultiplexer, video decoder and renderer, audio decoder and renderer
play it to see that it works.
during playing, right click on the video renderer and look at proprietaries: fps and jitter (ms)
fps must be near 30 fps and jitter few ms ( little more than first two tries)

4- create TS a file from you camera and check it with StreamXpress.
just delete from precedent graph the demultiplexer, video Mpeg2 decoder +video renderer and mpeg audio decoder +audio renderer.

at the Mpeg multiplexer output, add a dump filter. It will ask for a filename. name it as you want but with extension .ts.
play graphedit
stop graphedit
you will obtain a ts file on your hard disk
play it with StreamXpress.

If you have made a good job with wright parameters, StreamXpress will play it and display parameters it find.
a good option is to have a analyze software and do a larger analyze of your file ( PCR and ....). You can find demo softwares on the net.

5- Sony camera --> -------------> ----------- > DTA107

If all is ok. the last thing to do is to use Trilogic Decktec renderer filter to send in real time your stream.
Normally, you have just to delete the Dump filter and put Dektec Renderer in place of it.
take care of parameters:
Bitrate = exactly same as you wrote in multiplexer
modulation parameters : DVB-S
frequency 1280 Mhz
QPSK
fec 3/4
fofosize : 800000

save graph before play! ( Graphedit is not very stable)

Good luck!

Jean Pierre F6DZP
F6DZP
 
Messages: 665
Inscription: 24 Déc 2010

Re: acquisition DV, codage Mpeg2, multiplexage et modulation

Messagede W8KHP » Mer 7 Sep 2011 17:14

Pierre,

Thank you very much for your reply. You have given me some things to try out. So far, trying several things, I see that my fps is too low and jitter too high. I'll look into that some more.

73 Al W8KHP
W8KHP
 
Messages: 2
Inscription: 23 Juin 2011

Re: acquisition DV, codage Mpeg2, multiplexage et modulation

Messagede F6DZP » Mar 29 Nov 2011 17:26

Here is the happy end of exchanges via email:
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Hi Allen,
If your computer is not too old,( dual core or best) it can code and modulate in real time.
I will help you to find wher is the problem.
Could you tell me at what step your fps is low?
I usually use Mainconcept filters.
Elacard has similar filters, but I don't know how fine they all work as we need, I will check them when I 'll go back to my home next week.
some filters are very better than others because they use less CPU power, add GPU coding possibilities and give less jitter.
I have compared all mpeg2 coder and decoder that have been able to find, measuring CPU use, fps, jitter...
for coding video best is Mainconcept filter
for decoding video, best is on Windows7 : Microsoft decoder filter given with W7, on Win XP : Nvidia decoder filter
Elecard MPEG-2 Video Decoder 16k is also a good filter, not the other elecard decoder
for decoding audio with Win7 best is Microsoft , with Win XP ffdshow is a good choice.

The choice of the couple : video decoder and audio decoder is very important. sometimes some video decoder used with some audio decoder reacts very badly.

Another thing that allow good results is to have a graphic card that can help for software coding and decoding and filters that uses this GPU features.
( I don't talk about cards like PVR150 but just your standard graphic card. That can change life to use graphic card that allow that. These graphic cards are not strong graphic cards for playing game that can be very bad for Mpeg2 and very good for playing 3D games.

Could you tell me more about your equipment? CPU, windows version and graphic card?

We will find a solution.

73
Jean Pierre F6DZP
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hi Jean Pierre,

I am going to systematically run several possibilities and carefully record results. In the mean time here is information about equipment:

CPU: Intel Core 2 Duo E8200 @ 2.66GHz
Windows Version: XP Professional SP3
Graphic Card: NVIDIA GeForce 210

The Elecard filters I got as a demo. They sent me HD MPEG-2 encoder. Does that make a difference? I would try Mainconcept filters if I knew what demo to request. I am trying to keep expenses down until I know what works. I would hate to buy a whole package from Mainconcept and then find it does not work. Do they sell individual filters to hobbyists at a reduced cost?

I will get back to you with additional information as soon as I try a few things.

Thank you.

73

Al W8KHP
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hi Jean Pierre,

I have tried some things and the results so far are in the attached Word document. I am awaiting a fire wire cable to connect the camera directly to the computer by this means. The usb connection perhaps is not fast enough. Going through the Hauppauge card appears to be fast enough but adding filters slows things down.

73

Al W8KHP
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
graph test DV capture and renderer.jpg
graph test DV capture and renderer.jpg (67.5 Kio) Vu 23136 fois

Here I have connected the Sony camera to the computer by way of USB port. As you can see the fps is only 17 and the jitter is 49.

Then I connected the video encoder and right clicked and the decoder and renderer appeared. The fps dropped to 4.58 and jitter went up to 210.

I then opened up the various tabs on the encoder so that you can see what options I have so that you can guide me on what settings to select.

I then took my output from the camera from an A/V jack and went into the Hauppauge board. There fps was 29.80 and jitter was 2.

Then I went through the video encoder and decoder again and the fps was 9.92 and jitter was 6.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Hi Jean Pierre,

Haven't hear back from you yet but thought I would bring you up to date. I got the firewire cable and used it to connect the camera to the computer. I now have the Microsoft camera and dvr filter appear. Taking the video ouput I go through the DV Video decoder to the video renderer. The fps is 29.95 and jitter 1. Next going from the DV Video Decoder to the Elecard MPEG-2Video Encoder HD to the Elecard MPEG-2 Video Decoder HD to the Video Renderer the fps is 14.86 with jitter 26. Looking at the properties of the Video encoder it says average speed of 30. I then add the Elecard MPEG Multiplexer and right click on the output, it gives me a MPEG-2 Demultiplexer abut with no output pin. So I went ahead and deleted the demultiplexer and added a dump filter and created a .ts file. The file successfully plays in Streamexpress. I then connect the Elecard MPEG Multiplexer to the Trilogic MPEG-2 Transport Dektec Renderer. This time it attaches OK. There is activity because I can see the FIFO load changing. However the Dektec never starts transmitting. I feel like I am getting closer but still no there!! I assume it has something to do with some settings. Perhaps when you look at the material I sent you you will see what settings I have to "get correct"

Thank you once again.

73 Al W8KHP
F6DZP
 
Messages: 665
Inscription: 24 Déc 2010

Re: acquisition DV, codage Mpeg2, multiplexage et modulation

Messagede sajberista » Mer 14 Mar 2012 20:18

Greeting to all,

I readed all of your posts and i am ready to try this with my dektec, can you please send an adreess where i can find trilogic mpeg-2 dectek renderer filter?
sajberista
 
Messages: 1
Inscription: 14 Mar 2012

Re: acquisition DV, codage Mpeg2, multiplexage et modulation

Messagede F6DZP » Lun 19 Mar 2012 18:03

Hello,

The Directshow filter can be downloaded here:

Dektec Renderer.zip
(263.99 Kio) Téléchargé 1214 fois


Jean Pierre F6DZP
F6DZP
 
Messages: 665
Inscription: 24 Déc 2010

Forums Statistiques

Qui est en ligne

Utilisateurs parcourant ce forum: Aucun utilisateur enregistré et 1 invité

Options

Retourner vers Les filtres Directshow, les Graphes, GraphEdit