Closed Captioning with Matrox MXO2
on Mac OSX
Complete HD/SD closed captioning and subtitling solution.
No additional CC hardware required. No generation loss!!!
Avid Media Composer 6.0 and Matrox 4VANC
Avid Media Composer 6.0 adds support for the Matrox MXO2 and Mojito I/O devices, which have a unique solution for HD closed captioning (including down-conversion to SD) when used in Mac OSX. For more info please read: Avid and Matrox 4VANC.
Note: This page refers to the MXO2 4VANC workflow on Mac OSX only. As of April 2012 this option is not available on Windows yet. However Windows users with the MXO2 and Adobe Premiere CS5.5 or later can use the Adobe Premiere Pro workflow using MCC/SCC files (downconversion of HD to SD with captions is not yet supported).
Matrox and CPC have co-developed an innovative solution that allows the MacCaption HD and DTV software to encode and decode HD and SD captions to and from any HD or SD decks using the Matrox MXO2.
Matrox MXO2 and MacCaption users can now save both time and money by encoding HD and SD captions directly on their Final Cut Pro systems, without any additional hardware and with zero generation loss. It is no longer necessary to send master tapes to a separate deck-to-deck hardware caption encoding system. Existing closed captions are preserved during capture and print to tape operations, and the captions can be edited or re-purposed for multiple tape formats, optical disk delivery, and the web.
The MXO2 can also up/down/cross-convert any video format to any other format while maintaining the captions. You can simultaneously print your timeline to both HD with 708/608 captions and SD with 608 captions.
The Matrox 4VANC file format is small enough to send by e-mail, which means captioners can send an HD/SD captions file to a remote Matrox MXO2 user, who simply drops this file onto their Final Cut Pro timeline and can play back without any rendering.
Update 5/2010: The MXO2 latest drivers (1.9) now support 16 audio channels as well as Active Format Description (AFD). As a result, the workflow below has changed slightly. The CC track now goes on channel 16 instead of channel 8. If you are still using the older pre-1.9 drivers, the track should continue to go on channel 8.
How it Works
Importing Matrox 4VANC audio file into Final Cut Pro
MacCaption can export a special audio-only file that contains Matrox 4VANC closed captioning data for 608/708 TV broadcast standards. In addition, MacCaption can embed the 4VANC audio channel into a QuickTime movie resulting in a new QuickTime file that contains 16 audio channels. Both of these output files are wrapped in an MOV container and are able to be read by the Final Cut Pro timeline. The audio-only Matrox 4VANC has the .MOV extension, but in fact only contains 1 channel of audio data and is read accordingly inside Final Cut Pro.
Once the user imports the MacCaption generated Matrox 4VANC audio file into Final Cut Pro, the sequence settings must be set to support 16 channels of audio with channels 15 and 16 set to mono. To set this operation in Final Cut Pro, follow the instructions below:
- Start a new sequence or select the sequence opened that contains the video that is ready to be output via the Matrox MXO2.
- Go to top menu and select Sequence > Settings...
- Select the "Audio Outputs" tab and change the "Outputs" parameter to 16.
- Output 15 and 16 should be set to Dual Mono.
- Press OK.
- Drag your Matrox 4VANC audio file into any of the audio tracks beneath your video on the Final Cut Timeline.
- Control-click or right-click on the "Source" field to the left of your audio track containing the 4VANC audio file.
- In the drop down menu of the "Source" field select Audio Outputs > 16. (This will route your Matrox 4VANC audio file to channel 16 of the MXO2 board for Closed Caption insertion).
- Go to OS X System Preferences and select the Matrox MXO2 preference pane.
- Select the "Captioning" tab in the preferences and enable Matrox 4VANC Playback by placing a check box next to "Retrieve closed captioning from audio track 16."
- Select "Embed in SDI VANC (HD/SD) if you are printing to an HD-SDI compatible VTR (such as an HDCAM, XDCAM, DVCPRO-HD, etc. deck) or appliance (Omneon Server, Optibase Encoder, etc).
- Select "Embed in SDI Line 21 (SD) if you are printing to an SDI compatible VTR (such as Digital Betacam or DVCPRO50 deck).
- Select "Embed in analog Line 21 (SD) if you are printing to an analog compatible VTR (such as Betacam SP, Umatic, or SVHS deck) via composite, component, or S-Video.
- Close the Matrox System Preferences and go back to Final Cut Pro.
- Print to tape with closed captions. (no rendering required)
The sequence timeline in Final Cut Pro can be in either SD (720x486 or 720x480) or HD (720P, 1080i, or 1080p). The Matrox MXO2 will support closed caption data for any codec or resolution that is compatible with Final Cut Pro and the Matrox MXO2. Some of these include: DV25, DV50, DVCPRO HD, ProRes, XDCAM HD, Uncompressed 8bit and 10bit. Furthermore, changes can be made to the video on the timeline such as color correction and graphic lower third additions without affecting or deleting the 4VANC captions.
Upconverting and Downconverting video with closed captions using the MXO2
The Matrox MXO2 can upconvert and downconvert closed captions from SD to HD and vice versa along with the video. For example, If there is a 1080i video clip on the Final Cut Pro timeline It can be output to HD-SDI with VANC closed captions, or the video output can be set from the Matrox MXO2 to downconvert the video signal to SD 720x486 with Line-21 closed captions without any rendering. The Matrox MXO2 can output to HD-SDI and its SD analog outputs (composite, component, S-Video) simultaneously with closed captions. The MXO2 HD-SDI outputs will carry the 1080i signal with VANC closed captions, while the analog outputs will carry the line-21 respectively. Although the Matrox MXO2 has two SDI outputs that can both be set to output HD-SDI or standard definition SDI, they cannot be set to output independent formats. The MXO2 user must choose to output either HD-SDI or standard definition SDI from both outputs. However, HD-SDI can be output simultaneously with SD analog using the settings seen below:
The Matrox MXO2 supports down-converting HD video with VANC captions to SD video with line 21 captions. You can simultaneously print your timeline to both HD with 708/608 captions and SD with 608 captions. This also allows you to proof your 4VANC caption track on a regular TV with a CC decoder, instead of needing an expensive HD-SDI caption decoder. The MXO2 can also up/down/cross-convert any video format to any other format while maintaining the captions.
Monitoring HD closed captions
The MXO2 internally downconverts 708 caption data into 608 caption data for standard definition analog output (line 21). This means you can check that your captions are working using an inexpensive consumer TV with a CC decoder. If the line 21 captions are present then you know that the HD captions are working as well. You do not need an expensive HD-SDI 708 CC decoder to verify that captions are present.
To proof HD 708 captions on an external monitor, you need an HD-SDI device with a 708 closed captions decoder.
By default, most Sony HD decks are factory set to not record VANC Line 9 where the HD closed captions are stored. You must go into the deck setup or maintenance menu and look for the "VANC Packet RX" setting. This should be set to: VANC Line 9, DID 61, SDID 01. The exact menu depends on your deck. See our Sony HD deck settings for closed captioning page for some of the settings we know, or please contact Sony for more information.
Also, please be aware that most Sony decks do not output HD VANC data to the monitor outputs during live monitoring or recording, only during tape playback. If you are trying to monitor your captions, please connect your HD-SDI monitor w/708 caption decoder directly to your MXO2 instead of the deck, otherwise you must first record to tape and then play the tape back to see captions on a monitor connected directly to the deck.
Finally, please be aware that some kinds of HD decks do not support HD closed captioning at all. These include:
- Panasonic AJ-HD1200 (the AJ-HD1400 deck is ok)
- All XDCAM EX decks (XDCAM HD decks are ok)
- All HDV decks
Can't see captions on external device:
- Make sure you follow the above procedures exactly and do not get any error messages during the export or playback steps.
- Make sure your deck is correctly configured to record VANC Line 9 captions, and keep in mind that Sony decks do not loop through VANC data to the monitor outputs except when playing back from tape.
- To monitor captions on a regular consumer TV, connect it to the MXO2's composite output and make sure your MXO2 Analog output is set to "SD Channel" (see above). Also make sure your TV's CC decoder is turned on and set to CC1.
- To monitor HD 708 captions, you need an HD-SDI device which is capable of decoding HD CEA-708 closed captions. Consumer monitors connected by HDMI or component CANNOT receive captions this way. You can use an external HD-SDI closed captions decoder connected to a HD-SDI to HDMI converter to preview captions on a HDMI monitor. The best option is to use a HD-SDI professional monitor or waveform monitor with a built-in or add-on CEA-708 decoder. See "Monitoring HD closed captions" above for more information.
MacCaption + Matrox MXO2 Deliver HD Captions
Rockville, MD, April 9, 2009: The wait for a HD-SDI closed captioning solution for non-linear editors and caption service companies is finally over. Matrox and CPC have co-developed an innovative solution that allows the MacCaption HD software to encode and decode HD captions to and from HD decks using the Matrox MXO2.
Improves Workflow and Lowers Captioning Cost
Matrox MXO2 and MacCaption users can now save both time and money by encoding HD captions directly on their video editing systems, without any additional hardware and with zero generation loss. It is no longer necessary to send HD master tapes to a separate deck-to-deck hardware caption encoding system. Existing closed captions are preserved during capture and print to tape operations, and the captions can be edited or re-purposed for multiple tape formats, optical disk delivery, and the web.
e-Captioning for Fast Delivery
Caption service companies will also greatly benefit from this new workflow. Similar to CPC’s patented "black movie" method for SD captions, MacCaption generates a Matrox 4VANC captions file that is small enough to send by e-mail. Editors can then, without any captioning software or additional hardware, easily add this file to their timeline. When the non-linear editing system prints to tape, the MXO2 patent-pending technology takes this encoded caption data and translates it to EIA-708 closed captions through its HD-SDI output.
File Size and Format No Longer an Issue
Until now, encoding HD captions via software required up to 3 times the disk space of the original file. However, the Matrox 4VANC file takes less than 5 Megabytes per hour. Whether editing in full uncompressed HD, HDV, or any other codec, this file that carries the encoded captions can easily be archived locally or transferred over the internet to any MXO2 user.
CPC - The Closed Captioning Software Leader
HD captioning with the Matrox MXO2 is the latest addition to CPC’s industry-leading line of Macintosh and Windows closed captioning and subtitling software. Since releasing the first simultaneous closed captioning/teleprompting software in 1986, CPC has been the captioning and subtitling industry leader. CPC also operates an award winning captioning and subtitling service. For more information, please visit http://cpcweb.com/mxo2/
Matrox Video Products Group is a technology and market leader in the field of HD and SD digital video hardware and software for realtime editing, audio/video input/output, DVD/Blu-ray authoring, capture/playout servers, clip/still stores, and CGs. Matrox's Emmy award-winning technology powers a full range of content creation and delivery platforms used by broadcasters, post-production facilities, project studios, corporate communicators, and videographers worldwide. Founded in 1976, Matrox is a privately held company headquartered in Montreal, Canada. For more information visit http://www.matrox.com/video.
Matrox is a registered trademark and Matrox MXO is a trademark of Matrox Electronic Systems Ltd. All other trademarks are the property of their respective owners and are hereby acknowledged.