Capturing/digitizing video or stills

Easy version

1. Use the Web interface to route the relevant deck to moviola. Moviola only has digital input, not composite. If it's a digital deck like the digibeta, then route directly by middle-clicking the deck and left-clicking moviola. If it's not digital, then you'll need to route through a transcoder like FS1 or FS2: middle-click the deck, left-click a transcoder, then middle-click that transcoder and left-click on the moviola item in the list on the right (under Computers).
2. If you're making a movie and if you don't already have a directory on the /nle directory on moviola, make yourself one. That's a 30GB fast local disk array dedicated to video stuff. You need to capture to a local disk to get high enough bandwidth, don't even try using a NFS-mounted one.

3. Start up the capture program on moviola from your /nle subdirectory. (It's also known as mediarecorder

4. You can either capture movies or still frames. The movie icon is the leftmost one on the bottom left (the little camera), the still frame icon is the rightmost of those three (the face).

5. In either case, you want to pick the Digital option under the O2 Video Hardware item.

6. If you're making a movie, select Tasks->Movie->Video Production(JPEG) from the menus to create fullsize frames with hardware JPEG compression. You can use the Show Tasks Settings under the Tasks menu to customize the size and compression. I recommend that you use JPEG compression if you want nice smooth motion. Using any of the other (software) codecs or no compression at all will result in a jerky movie. I also recommend using the popular QuickTime movie format instead of the obscure SGI movie format, provided only for backward compatibility.

7. If you're grabbing a still frame decide on the size (full, half, quarter) and format (SGI/RGB, TIFF, GIF, and JPEG/JFIF), either by picking something preset from Tasks->Image or going totally custom through Tasks->Show Task Settings.

8. Decide what directory you'd like your saved files to be saved into. Use the text input box on top of the browser area on the right. Note that if you're saving movies, you should save onto local disk to minimize chances of missing frames.

9. The record button is the little red circle in the lower right. If you're capturing a still image, just hit the button once. If you're capturing a movie, you'll need to hit the record button to start and the blue square stop button to finish. The screen will freeze briefly after an image capture. After a movie capture, more processing will happen, as shown by a dialog box.

10. You can view saved images or movies from the browser on the right. If you doubleclick on a movie file, it will automatically play on the left. If you doubleclick on an image file, it will appear on the left. To return to previewing the video input source, hit the blue square stop button.

11. You can change the default name if you want by clicking on the text. If you just keep clicking the record button, the filename auto-increments.

More detail

• You can use the standard image processing tools on the SGI to change your image files into another format. For example, "togif image1.rgb image1.gif", or "sgitopnm < image1.rgb | pnmscale -xysize 100 100 > smallimage1.ppm", or "convert image1.rgb image1.jpg". You can always use xv if you want to convert using a GUI.

• For simple video processing, you can use the movieconvert program on the SGI. For more complex processing, use Adobe Premiere on the SGI or Avid MCXpress on the PC.

• If you want frame-accurate control over the deck as you capture, or want to set up many precise batch captures, use Adobe Premiere instead of capture.

• If when you try to use JPEG compression you have trouble or get error messages, try reseating the video board. The connection has been known to be flakey in the past, perhaps because moviola is in a location where it gets kicked often. See Moviola's troubleshooting section for exact symptoms and how to fix.

1. Make sure you're using hardware JPEG compression. The software codecs will definitely drop frames. Uncompressed video is the worst of all, we definitely do not have enough bandwidth to get a 14MB/sec stream onto disk.

2. You can tell capture to abort if frames are dropped while capturing a movie. It's a radio button under image in the Task Settings panel. This is much easier than doing the whole capture, and then eyeballing it.

3. Make sure you're recording on to the local disk, not your NFS-mounted home directory. Moviola has a big local /nle partition just for video recording.

4. You should turn off audio capture if you only care about video, since it's on by default and takes up bandwidth. Pick the "Do not record audio track" radio button under the Audio tab on the Task Settings panel.

5. All of the above suggestions are lossless. You should be able to digitize fullsize video smoothly using the JPEG hardware. If somehow you're still having trouble and are desperate, here are some suggestions that will lower the quality of your video, but at least in a manner of your own choosing:

   • Reduce from fullsize frames to halfsize frames.

   • Reduce the frame rate from 30 to 15, under the logic that it's better to have lower temporal resolution than random jerkiness.