Archive for the ‘video’ Category

Recording and Archiving TV Is Still Not Simple

January 2, 2010

We have Comcast cable TV with a digital tuner box that contains a hard drive to support video recording. When its hard drive filled up with shows we wanted to watch in the future, I had to figure out how to save them somewhere else to free up disk space for new recordings. As I pondered how to do it, I thought back a few decades and wondered why this process can still be cumbersome, given the improvements in technology….

In the 1970s, it became possible to record shows from your TV for viewing later, using a video cassette recorder (VCR). This is called time-shifting, and was ruled to be legal by the U.S. Supreme Court in the infamous 1984 “Betamax case”.

Doing this required learning how to program your VCR using its primitive interface and looking up show times on a printed TV schedule in a newspaper or TV Guide magazine. You could archive the shows you wanted to watch later by storing the video tapes.

In 1999, TiVo introduced a hard disk based digital video recorder (DVR), which downloaded the TV guide over a phone line or (later) the Internet. This let you choose shows to record by name; TiVo even records shows it thought you might like. For archiving, hobbyists figured out ways to get the recorded MPEG2 video files off of the TiVo’s hard drive and onto a home computer’s hard drive, where they could then be stored, viewed on a computer, burned onto DVDs, or converted into other formats such as MPEG4.

That was a great arrangement, but the TiVo boxes cost several hundred dollars plus a recurring subscription fee for the guides, and TiVo gradually made them harder to hack into to get the video files. The cable TV companies (like Comcast) started offering their own, simpler DVR boxes for cheaper (just the monthly fee). Our is made by Motorola. It has some computer connectors on the back, like Firewire, which aren’t enabled by the Comcast software on it.

So, how to copy shows off of the Comcast DVR? It’s ridiculous, but I have to record the shows in real-time into a computer. I got a Canopus ADVC-110 DV capture card that connects by Firewire to a Mac laptop running Final Cut Express, and by S-Video and RCA audio to the Comcast DVR. After I capture each show from the Comcast DVR into FCE, I trim out the commercials (replacing them with chapter markers), black out the in-frame ads for other shows with cropped slugs, de-letterbox by zooming if applicable, and save it as a QuickTime DV file that I can re-encode into MPEG2 for a DVD. There’s no good technical reason for these extra steps, just corporate politics.

I also use the Canopus to capture video from VHS tapes and analog camcorders, so I needed it anyway; I didn’t get it just to save shows from the DVR. Otherwise, I might have considered getting a TiVo and a CableCard. Other possible capture devices include:

  • A standalone DVD recorder to skip the re-encoding step, but that wouldn’t let me cleanly edit out commercials or re-encode for viewing on computers or portable devices.
  • For smaller captured file sizes, a capture device that encodes in MPEG4 instead of DV, such as the Elgato Video Capture. That would mean editing out the commercials using QuickTime Pro 7 or MPEG Streamclip, instead of Final Cut or iMovie. I find the Final Cut interface easiest to use and it gives me the most power in editing.
  • To capture HD, I’d have to use something with component video inputs like the Blackmagic Intensity Pro PCI-e card, but I don’t have a Mac with PCI-e slots near my TV. Or the Hauppauge HD PVR, which encodes in AVCHD format, which I would need to decompress to edit. And HD video uses even more disk space. Someone else has written up a procedure to convert HD video captured by a Hauppauge HD PVR into a standard-def DVD, for those who want to try that.
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iDVD Tips

August 11, 2009

For authoring a DVD of home movies, my preferred program is currently iDVD 7, which is part of iLife 08 and 09. It’s a pretty easy way to get attractive menus and excellent looking rendered video, but it does have some annoying limitations and bugs. Here are some tips for using it.

  • If possible, select Professional Quality (2-pass VBR) in the Project Info. If you have time to wait, you might as well get the highest quality encoding. For details on the iDVD encoding options, see What iDVD ’08 Compression Options Really Mean and Review: iDVD ’08 and iDVD 7.
  • Turn off the Apple watermark in Preferences.
  • Use a menu without fancy animation. The default menu in iDVD 7 can take longer to encode than the movies do.
  • To save encoding time and space on the DVD, you can open the Inspector (command-I) on each menu and uncheck the boxes for the various animated effects and bring the loop time down to zero. Or, less drastically, in themes with animated thumbnails, you can select the Inspector boxes to use a still image instead. After changing a menu background (even to a still image), make sure the loop time is still zero; iDVD seems to reset it.
  • I usually turn off the menu sound for each menu, by dragging the sound out of the Inspector box. Menu sound is annoying.
  • If you update or re-render a movie you have added to iDVD, iDVD will detect the change and offer to update the project. If the movie has chapter markers, iDVD won’t update the project correctly; you need to remove that movie from the project, probably quit iDVD and relaunch it, and re-add the movie.
  • iDVD does not support anamorphic widescreen DV files, interpreting them as 4:3 instead of 16:9. The workaround is to change the display size of the DV file using QuickTime Player 7. You can avoid modifying the DV file by saving a QuickTime reference file with the 853×480 display size. Pre-Snow Leopard, you might need to buy a QuickTime Pro license. In Snow Leopard, QuickTime Player 7 isn’t installed by default, so you might need to install it from the Snow Leopard DVD (it will end up in the /Applications/Utilities folder). In Lion, you need to download it from Apple.
  • Preview the DVD to make sure it looks the way you want.
  • If you mix 4:3 and 16:9 videos on one DVD, iDVD will probably mix up some of the aspect ratios. To fix the aspect ratios:
    1. Save as a VIDEO_TS folder in iDVD.
    2. Use myDVDEdit to check and fix the aspect ratio in each VTS (either 4:3 or 16:9 auto Pan&Scan and Letterbox).
    3. Burn the VIDEO_TS folder with Burn or LiquidCD.
  • To include videos that are already encoded as DVD-compliant MPEG2 in an iDVD project (assuming they don’t need chapters):
    1. If you have an MPG file or a VOB with no IFO, demux and remux as needed to make a VOB and IFO, using a program such as ffmpegX.
    2. Include a short dummy video in the iDVD project as a placeholder.
    3. Save as a VIDEO_TS folder in iDVD.
    4. Duplicate the VIDEO_TS folder in Finder.
    5. Open myDVDEdit on the VIDEO_TS folder to figure out which VTS number each placeholder video is.
    6. Replace each placeholder VOB and its IFO and BAK files with the real ones in the duplicate VIDEO_TS folder using the Finder (renumber their file names as necessary).
    7. Open both the unmodified and modified VIDEO_TS folders in myDVDEdit. myDVDEdit will probably report and fix some errors in the modified folder; that’s normal and good.
    8. Make new empty PGCs in the menus as needed to make the same number as in the iDVD-authored IFO.
    9. Use Select All with copy and paste to copy the iDVD menu navigation pre and post commands from the iDVD-authored placeholder menu PGCs to the replacement video.
    10. Play the VIDEO_TS folder with both VLC and Apple DVD Player. While playing the video you replaced, make sure the sound, seek bar, and Menu button work.
    11. Burn the VIDEO_TS folder with LiquidCD.

I Want Pro Tools for Video

July 17, 2009

In almost every respect, working with digital video is less mature and less streamlined than working with digital audio. The user interfaces of editing software are no exception.

I’ve spent much of the past decade editing digital audio, and since 2002 my favorite program for that is Pro Tools by the Digidesign division of Avid.

In the past year, I’ve gotten more serious about video editing. After dabbling with Sony Vegas, Windows Movie Maker, and iMovie HD (among others) for a couple of years, I now mainly use Apple Final Cut Express.

I find working in video editing programs unnecessarily primitive and cumbersome compared to Pro Tools. Taking Final Cut Express/Pro as a typical and popular example that I’m familiar with, here is my list of deficiencies compared to the audio editing programs I’m used to. It’s in no particular order.

  1. I can’t name or add comments to tracks. I’m stuck with “V1” and “A1” to identify the tracks.
  2. No way to change the order of tracks. It’s unbelievable that this isn’t supported. I have to jump through hoops creating temporary tracks and selecting and moving the contents of other tracks in order to accomplish the effect of, say, inserting a track between two others or moving one track above another one.
  3. No effect inserts on tracks. I can’t put an effect on a whole track; I have to add it to each clip on the track. If I change a parameter, I have to change it in every similar clip instead of just once.
  4. Files for each project are scattered in various directories, making it more difficult to archive or copy a project. Pro Tools encourages keeping all the files for a project under one folder. Final Cut discourages it by making the location of folders like Render Files a global setting instead of per-project. That’s one of the things that drove me away from Cakewalk for audio years ago. It’s too easy to wind up with files for a project getting written to the wrong hard drive and not know it until you reopen it and discover things are missing.
  5. No smart recalculating. Spreadsheets do it, but Final Cut doesn’t. If I add a keyframe anywhere in a clip (such as to do a fade-in or fade-out), the whole clip is invalidated and needs to be re-rendered, even if only a tiny part of it between two keyframes is obviously the only part affected, Final Cut makes me waste a lot of time re-rendering unchanged footage. My partial workaround for this flaw is to use the razor blade tool to split a clip into two near each area where I’m going to add keyframes. Which creates its own problems if I change any effects or other settings on the region–now I have to remember to change them in several regions because of the split.
  6. Audio waveform recalculation isn’t cached. Toggle waveform display with Command-Option-w (which isn’t listed as a keyboard shortcut on the Sequence>Settings menu, another bug), and Final Cut recalculates all the audio waveforms from scratch every time. It’s so slow at this that it’s often not practical to work with waveform display turned on.
  7. No easy way to temporarily disable a clip in a timeline. In Pro Tools, I can press Command-m to mute a region without changing it, to experiment with different mixes without losing editing work. In Final Cut, I have to create a copy of the whole sequence to experiment on.
  8. No master audio or aux or VCA tracks.
  9. Precise audio sync is difficult. Apple documents a workaround to do subframe audio slipping that involves shift-dragging and setting an in or out point, but it’s clumsy and usually doesn’t work when I try it. I normally resort to exporting the existing audio track into a wave file, importing it into Pro Tools, and aligning additional audio in Pro Tools and re-exporting it and importing that into Final Cut. Despite all the extra steps, it’s easier and more reliable than trying to sync audio in Final Cut.
  10. Inability to move markers once they’re created. If because of an edit or a mistake, I find that a marker isn’t where I want it to be on the timeline, I have to delete it and create a new one.

I don’t have much hope that any of these flaws will ever be fixed. I wish there were a video editing program with as good an interface as Pro Tools! (Avid sure doesn’t make one–their video editing software is even more cumbersome than Apple’s, from my experience playing around with it.)