Converting Closed Captioning to Text Using Capture Cards

A TV capture card

GraphEdit (http://www.digital-digest.com/dvd/downloads/showsoftware_graphedit_141.html#downloads)

SCC Tools (http://www.geocities.com/mcpoodle43/SCC_TOOLS/SCC_TOOLS.ZIP)

GraphEdit itself is a very useful Windows program that can be used to convert nearly, if not all, video and audio formats. As well as capture video and record audio playing through your soundcard. But we'll be focusing on taking Closed-Captioning data from a TV signal

GraphEdit Filters

The first thing you need to do is to extract both GraphEdit and SCC Tools somewhere you'll remember.

Now open up GraphEdit and you'll be presented with a window with not much going on but that'll change once you start adding objects.

Click on the Graph menu and then Insert Filters. Scroll down to WDM Stream Capture Devices and click the plus sign. Select the name of your card and click the Insert Filter button.

Now find WD Streaming Crossbar Devices and again add the item with the name of your card. Only this time it should end with Crossbar.

Next, insert the Tee/Sink-to-Sink Converter under WDM Streaming Communication Transforms

Under WDM Streaming VBI Codecs click CC Decoder and insert that filter.

In the DirectShow Filters section insert Video Mixing Renderer 9. Within that same section insert a Line 21 Decoder and a Color Space Converter filter.

Lastly, for this part, insert a Dump filter. An output file dialog should pop up asking you where to save the encoded Closed-Captioning data. So save it with a .bin extension and in the place where you extracted SCC Tools. Close the Insert Filter Dialog.

Connecting the GraphEdit Filters

Now we're half done but pay attention to the details of these steps since they're also important.

Right-click on the Crossbar and select Filter Properties. In the properties box that pops up choose the source of your video signal, which is most like Video Svideo In, under Input. Once that's chosen click OK.

Drag a connecting arrow from the little box to the right of 0: Video Decoder from the Crossbar to the little box to the left of Analog Video In of the big Capture box.

From the Capture box's VBI output, drag the arrow to Communication Transform on Tee/Sink-to-Sink Converter.

Now from the Tee/Sink-to-Sink Converter Splitter output connect an arrow to CC Decoder's VBI input.

Connect and arrow from the CC output of the CC Decoder to your .bin output module. Connect the other CC to the Line 21 Decoder's XForm In.

Now connect Line 21 Decoder's XForm out to the Input of the Color Space Converter. Now take the Color Space Converter's XForm Out and connect it to Video Mixing Renderer 9's Input2 and the Capture Box's Preview to VMR Input 0.

Lastly, for this part, click Graph Menu and press play. Wait until whatever show you're saving Closed-Captioning data from is over and then press stop. Save the GraphEdit .GRF file and exit GraphEdit.

Converting the GraphEdit Output

For the last step create .bat file and name it something like bin2txt.bat. Add these two lines to the .bat file:

raw2scc -1 CAPTUREDFILENAME.bin OUTPUT.scc

ccasdi -s OUTPUT.scc OUTPUTNAME.txt

"OUTPUTNAME.txt" should now be the plain text version of the .bin file from GraphEdit and you're done. Now go experiment with GraphEdit to find different methods of capturing other types of data.

I hope you enjoyed this tutorial.