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2014-12-10

Stuff I found useful in transferring VHS video using a Hauppauge USB-Live 2 digitizer with Linux (Lubuntu 14.04, to be precise):

  • http://ivtvdriver.org/index.php/V4l2-ctl
    • This tool can be used to set the device to capture NTSC. The command I used was:
      • v4l2-ctl -d /dev/video1 -s ntsc
  • http://www.linuxtv.org/wiki/index.php/MEncoder
    • The advice here to use GStreamer for "unstable sources" worked out. I had been using an mencoder command to capture video because that was the only thing I had successfully made work, before I discovered the right v4l2-ctl command. The problem with mencoder is that when the video signal drops out (as VHS tapes are likely to do), it starts to lose audio/video sync.
    • Also, I was only able to make GStreamer work if I didn't run the mencoder command at all. So, mencoder was leaving the device in some state that I couldn't figure out how to get it out of, short of rebooting.
  • http://www.linuxtv.org/wiki/index.php/GStreamer

The trick with GStreamer is figuring out the complicated "pipeline" to handle the signals correctly. Ultimately, I was able to capture audio and video and keep them reasonably synchronized by running:

    gst-launch-0.10 -v \
        --gst-debug-level=3 --gst-debug-no-color \
        avimux name=mux \
        v4l2src device=/dev/video1 do-timestamp=true ! \
            video/x-raw-yuv,width=720,height=480,framerate=\(fraction\)30000/1001 ! \
            videorate ! \
            'video/x-raw-yuv,framerate=(fraction)30000/1001' ! \
            queue ! \
            mux. \
        alsasrc device=hw:1,0 ! \
            'audio/x-raw-int,format=(string)S16LE,rate=(int)48000,channels=(int)2' ! \
            audiorate ! \
            audioresample ! \
            'audio/x-raw-int,rate=(int)48000' ! \
            audioconvert ! \
            'audio/x-raw-int,channels=(int)2' ! \
            queue ! \
            mux. \
        mux. ! \
        filesink location=gstreamer.avi

This is loosely based on the "Record from a bad analog signal" link above.

I converted the resulting file to MP4 with:

    avconv -i gstreamer.avi -c:v libx264 -b:v 4500k -c:a aac -b:a 360k -strict experimental -filter:v yadif=0:-1:0,setsar=8:9 -ss 12 -t 704 gstreamer.mp4

The "12" and "704" mark the starting time and duration to extract from the full raw file. Note the 'setsar=8:9', because the NTSC default is 720x480, with non-square pixels. I prefer working with square pixels, but I decided because MP4 has reasonable handling of different pixel aspect ratios, this would be good enough. (And maybe that additional 12.5% of oversampling makes some sort of huge difference in the picture quality. Nah, probably not.)

Update 2015-03-17: To losslessly trim the mp4 file:

    avconv -i gstreamer.mp4 -ss 15 -t 315 -vcodec copy -acodec copy avconv.mp4

Update 2015-07-14: AAC is the recommended audio format for uploading to YouTube?, but the above command may not produce the best audio quality. See https://trac.ffmpeg.org/wiki/Encode/AAC.


2012-09-09

You can find some very spot-on reviews of Beasts of the Southern Wild by Googling the title of the movie (in quotes) and "nausea":

Google search

For example:

reelviews.net: "To this day, I have never understood why some directors see value in filming their entire movie using a shaking, hand-held camera. The intent is to create a more gritty image and to enhance intimacy. More likely, however, it is apt to promote nausea and become a distancing factor."

All in One Boat: "I can’t give it a review here because within 30 minutes I had to leave. Not because of child cruelty but because of intense vertigo induced by shaky camera work and intensely loud music."

fromtheeditr: "When cameras are on a bumpy ride, out of focus, intentionally nausea-inducing, it is difficult to concentrate on any message the filmmaker might have for me. "

For me, it was like trying to read in a car for 90 minutes.


2012-01-18

Today, this site participated in the SOPA Strike. Thanks for contacting your representatives in Congress to help keep the Internet free.


2010-08-10

Here's the latest on my musical activities since, whenever:

  • I played and tweaked Moog synthesizer on "Orderly Universe", from Opposite Day's new EP Mandukhai. The whole thing is great -- get yourself a copy!
  • I contributed the "Playground Process Mix" to the Jacob Fred Jazz Odyssey's Tetherball Triumph remix contest. I took something of a Steve Reich approach to it, and used a Perl script and a calculator along the way. At over eight minutes, it was the longest entry. Be sure to listen in stereo, with headphones for maximum effect.
  • I contributed the "Rods and Cones Mix" to the Jacob Fred Jazz Odyssey's The Sensation of Seeing Light remix contest. This time, I submitted the shortest entry. My goal was to create a "re-composition" of the song, starting out with the feel of a quiet jazz club (think black & white -- rods) and building up to a blazing old-school electric Fred sound (think colour -- cones). (Unfortunately, as of 2011-10-02, these remixes no longer appear to be available on the JFJO site.)
  • I've written a couple songs so far this year.

2010-03-13

I'm going to try to record a song each month in 2010. I just finished January. The sooner I fall behind, the more time I have to catch up. Check it out, and watch this space for more songs when I get around to them.


2010-03-04

Why I liked the 2D version of Avatar better

I first saw Avatar in 2D, and it was beautiful. The visually rich environment of the planet was extraordinary. Many of the scenes seemed to be lifted (unacknowledged) from Roger Dean paintings, but I love Roger Dean paintings, so this was a joy to watch. I enjoyed studying the extensive detail filling many of the shots---the luminous forests and arcane wildlife made every "shot" (to use the term loosely) a feast for the eyes.

I decided I should take advantage of the 3D version while I could, so I went and saw it in one of the highest-quality screenings around. While there were times that the 3D effect was very cool and gave the images a more visceral quality, overall I found the effect distracting and not enjoyable. While objects in the shots did seem to exist in three-space, I found everything to have a sort of transparent flickery quality. By the end, I had a bit of a headache and my eyes felt funny.

Reflecting on the experience, I realized the origin of this feeling might be rooted in a quirk of the way the 3D effect is created. While sending a different image to each eye does create a stereoscopic focal point in space, the optical focal distance is always the actual distance to the screen. When viewing normal objects, these distances are always correlated. However, in a 3D projection like this, the stereoscopic distance and the focal distance are different, forcing the eyes to operate outside their normal parameter space. I suspect this subtle visual anomaly is behind the somewhat weird look of everything and the cause of the discomfort I felt by the end.

There was another factor I found annoying, at a more conscious level---the omnipresent awareness of the "camera". Even though the 3D image appears "real" in some sense, the frequent cuts and camera motions collide with that sense of reality. But an even greater sense of the "camera" comes from the fact that many of the scenes are rendered with a limited depth of field, as if they had been shot with an actual camera. Thus, for example, when one of the seeds of the tree of life goes floating by in the foreground, it's a big white blur. You can cross your eyes and look at it, but it's still blurry. And, there's still the problem that it's least blurry when your optical focus is aimed much further away than the apparent distance to the object.

Depth of field is a useful compositional tool, and can be used to great effect to direct the audience's attention to different parts of a shot. But I still like to study the whole frame and look at things that aren't the central subject. That to me is part of the point of seeing a film on a big screen---so I can see little incidental details that might be overlooked on a small display. Unfortunately, the 3D presentation of Avatar makes it inconvenient and uncomfortable to let one's eyes wander around a scene.

I decided to look around and see if anyone else had similar observations, and indeed they did:


2010-01-17

Bill Maher has written a great article on why you should move your money into a local bank. Check it out.