Capturing DVD Closed Captions with GraphEdit

This procedure describes how to capture raw closed captions from a DVD using the GraphEdit application and the drivers provided by your software DVD player. This method is rather long and cumbersome, so if at all possible, you should try the VobSub + VOBSUB2SCC method described on the main SCC Tools page.

First, there are two things you need to be aware of:

• In order to be able to capture closed captions using a software DVD player's drivers, that player must be capable of displaying closed captions or relaying them to a television set. Included in this list are PowerDVD, Sonic Cineplayer (fka WinDVD), and the Ravisent (Cinemaster) Player.
• In order for GraphEdit to access the DVD VOB files, those files must be decrypted. See Doom9 for help with this.

Here is the procedure for extracting closed captions from a DVD software player:

1. From Control Panel, double-click on the DirectX applet to find out what version you have installed (if there's no applet in Control Panel, find and run dxdiag.exe, probably located in the System32 subdirectory of your C:\Windows or C:\WINNT directory). If you don't have version 7 or higher of DirectX, download the latest version from Microsoft's web page.
2. Download the GraphEdit tool. This can be found by itself at Doom 9, or as part of the DirectX SDK at Microsoft. The SDK (at 215+ MB a rather-large download) is probably worth loading for only two reasons: it already includes DirectX (in case you need to upgrade), and its help file is useful for figuring out what the different DirectShow filters do (in the Contents tab, look under DirectX - DirectShow - DirectShow Reference - DirectShow Filters).
3. Start GraphEdit. Under the Graph menu, select Insert Filters, then insert all of the following:
• Under DirectShow Filters, select the "File Source (Async.)". This will open a dialog box--select the decrypted VOB file you wish to extract captions from.
• Under DirectShow Filters, select the "MPEG-2 Splitter". If you're using Windows XP, select the "MPEG-2 Demultiplexer" instead.
• Under DirectShow Filters, add the DVD video decoder filter for your software DVD player. The filter name will start with the name of the manufacturer, for example "Cyberlink Video/SP Decoder" for PowerDVD or "InterVideo Video Decoder" for WinDVD. For the Cinemaster DVD Video Decoder (and perhaps other hardware-driven DVD players), look under the WDM Stream Decompressors category for the "Cinemaster C WDM DVD Driver".
• If you're using hardware decoding, select the "VBI Surface Allocator" under DirectShow Filters. For Windows XP, select the "Video Port Manager" filter instead.
• Under DirectShow Filters, select the "Infinite Pin Tee Filter".
• Under DirectShow Filters, select the "Line 21 Decoder". If you're working in Windows XP, use the "Line 21 Decoder 2" instead.
• Under DirectShow Filters, select the "Overlay Mixer" (do not add this filter for Windows XP).
• Under DirectShow Filters, select the "Dump" filter. This is the filter that will output the raw closed caption file, and when you select this filter, you will be promted to provide a path and name of the file to create ("cc.bin" is a good name). The Dump filter comes with GraphEdit, and if you don't see it listed, then the register.bat file in the directory you put GraphEdit in didn't work. Open register.bat in Notepad and add the following line at the top: "set path=%path%;." (be sure to include the period at the end). Double-click the file, and see if it runs correctly, then close and re-open GraphEdit and try again.
• Under DirectShow Filters, select the "Video Mixing Renderer" for Windows XP or the "Video Renderer" for other operating systems. Then click the Close button to return to GraphEdit.
4. To create an application, you will now connect the filters (the boxes in GraphEdit) to each other to pass data down the line. To connect two boxes, position the pointer in an output pin (one of the bumps on the right-hand side of a box) and drag to an input pin (a left-hand bump on another box). If the two filters cannot be connected, you will get a cryptic error message--try closing and re-opening GraphEditor and if this and a reboot doesn't work, then it's possible the driver just doesn't want to do what you want. To configure a filter, right-click it and select "Filter Properties". Finally, to delete a filter, click on it to select it, then press the Delete key. Look here for an example of what this should look like when finished (using PowerDVD's DVD video decoder filter in a Windows 2000 system).
1. Connect the Output pin of the File Source filter (the one with the name of the VOB file) to the Input pin of the MPEG-2 Splitter filter (for non-Windows XP systems) or the same pin of the MPEG-2 Demultiplexer. After a few seconds, two output pins should appear on the MPEG-2 Splitter or Demultiplexer: Video and AC3 (or perhaps MPEG-2 Audio).
2. Connect the Video out pin of the MPEG-2 Splitter or Multiplexer to the Video In pin of the DVD video decoder filter.
3. Connect the Video Out pin of the DVD video decoder filter to Input0 of the Overlay Mixer (for non-Windows XP environments) or Input0 of the Video Mixing Renderer (for Windows XP).
4. Look for an output pin on the DVD video decoder filter with a name like "Closed Caption Out" or "CC Info" or "Line 21 Output" or something similar (the name could have a "~" before it, which means that the pin normally requires special handling). Connect this pin to the Input pin of the Infinite Pin Tee Filter.
5. If the dvd video decoder filter has a VPVBI output pin, connect it to the VBI Notify input pin of the VBI Surface Allocator filter (for non-Windows XP systems) or the same pin on the Video Port Manager filter. If the capture filter does not have this pin, then this filter is not needed, and can be deleted. In case you are wondering, the purpose of this dead-end filter is to allocate memory on the hardware decoder card to use the Closed Caption output pin.
6. Connect the Output1 pin of the Infinite Pin Tee Filter to the XForm In pin of either the Line 21 Decoder filter (for non-Windows XP) or the Line 21 Decoder 2 filter (for Windows XP). Note that an Output2 pin will appear on the Infinite Pin Tee Filter when you do this.
7. Connect this Output2 pin to the input pin of the Dump filter (named "cc.bin" or whatever you decided to name your capture file).
8. For non-Windows XP systems, connect the XForm Out pin of the Line 21 Decoder filter to the Input2 pin of the Overlay Mixer filter (which you used back in step c). For Windows XP, connect the XForm Out pin of the Line 21 Decoder 2 filter with the Input2 pin of the Video Mixing Renderer filter.
9. For non-Windows XP systems, connect the XForm Out pin of the Overlay Mixer filter to the Input of the Video Renderer. Windows XP users don't need to do anything for this step.
5. Save the resulting graph.
6. To capture closed captions, click on the play button in the toolbar of GraphEdit. A window should open showing the video with closed captions overlayed. There will be no sound, but as long as closed captions are being displayed, they will also be captured.
7. Monitor the preview window and/or the progress bar located under the toolbar in GraphEdit until all of the captions you are interested in have been displayed (or the file is done playing), then click the stop button in the toolbar of GraphEdit to stop recording. DO NOT close the preview window before stopping GraphEdit, as that will crash the computer (you should close the window once you have stopped GraphEdit, though). If you're extracting from the entire VOB file, the capture file output will stop as soon as the video stops playing, so you may not need to monitor this step after the first few times.
8. Take a look at the file you have created, to make sure that it is not an empty file. The contents of the file are in binary, so they should look like gibberish, with a few letters here and there.
9. To capture from another VOB file, configure the Dump filter to save to a different file, then delete the File Source (Async.) filter--the link between the MPEG-2 Splitter or Demultiplexer and the DVD video decoder filter will disappear at this time. Re-add the "File Source (Async.)" filter under DirectShow Filters and select the next VOB file, then reconnect this filter to the MPEG-2 Splitter/Demultiplexer and the Splitter/Demultiplexer filter to the DVD video decoder filter. To be honest, I have never been able to get any but the first VOB file to work using GraphEdit, so the solution may be to combine all VOBs into a single file at the very beginning.
10. GraphEdit cannot open a filter if a file it uses is missing, so be sure to delete the VOB file from the graph before saving and closing the program. This way, you can load the filter and continue from Step 9 above.
11. To combine the raw captions files extracted from sequential VOB files, bring up a command prompt, navigate to the directory with the files, and issue the following command: "copy cc1.bin+cc2.bin+cc3.bin cc_all.bin" (changing file names as necessary).

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