Posts tagged capture

Looking at Video File Metadata

Three choices as per the details here:

tcprobe -i filename
ffmpeg -i filename
midentify filename

Info on file types here.

I’m trying to understand video formats to make it easier to transcode for various purposes. I’ve found some useful links: > the DV, DVCAM & DVCPRO Formats

HDV vs HD: A Primer

Digital Video Formats and Video Conversion Explained

Video File Formats 101 : Formats Explained

Capturing Old VHS Tapes

Yes, I’m digitizing everything — it’s like all of my belongings are slowly being vacuumed up into the computer.

This time it is VHS tape I’m working on. I’m not concerned about commercially recorded tapes — I got rid of all of those a while ago. Rather, I want to capture the tapes we have which are irreplaceable. In our case that is mostly videos which feature people in our family that we recorded from TV or other sources.

I figured the simplest method would be to feed the video out from a VCR to the AV IN on one of my cameras, then sent the output via firewire to my computer for capture using dvgrab. Turns out it worked like a charm.

I found a great explanation of the process here.

I used my old Panasonic PV-GS700 which no longer records properly — it works just fine to convert the analog signal to digital output. I had to switch the camera’s “DV OUT” setting to “ON” and it was ready to go. Here is the dvgrab command I used to capture the video (where “foo” is the base output filename):

dvgrab –frames 0 –size 0 –format raw -noavc -showstatus -d 02:10:00 foo

Note: if you are keeping an eye on it, you can stop the capture at the actual end of the tape by pressing ctrl-c and the output file will still be fine. You don’t have to wait until the 2:10 mark — that is just for convenience so the capture doesn’t continue to run indefinitely.

As per the instructions in the link, the following command is a handy way to trim off the excess from the end of each file (where the time element is the place you want to end the clip):

dvgrab -showstatus -stdin -d 1:05:10 -s 0 foo-001_trimmed.dv < foo-001.dv

Hauppauge WinTV-HVR 950Q USB TV Tuner

I purchased a USB TV tuner device hoping to be able to do two things: a) receive (and possibly record) analog NTSC TV broadcasts, and b) accept analog input from a VCR to digitize some old VHS media.

After a lot of red herrings and attempts to install drivers, I finally understood that the device had been detected in Ubuntu Jaunty without any extra effort. Configuring the device was a little more complicated, however. I installed the following packages to help diagnose whether the device was working: dvb-apps, dvb-utils, w-scan. Unfortunately, I’ve discovered that apparently Video4Linux doesn’t support receiving analog signals with this device (my fault for not doing more research, I guess). We don’t have digital signals where I live (and I don’t have digital cable or any other usable sources available).

Potentially helpful info here and here.

Plan B: try to get the device running under Windows XP in VirtualBox.

Capturing from Canon Vixia HV40 in Ubuntu

I am very pleased to report that capturing from my new camera works like a charm.  I hardly had to do any tweaking to get it to work.

Here are some commands that worked for me to begin with:

  • grab video
    sudo dvgrab –autosplit –frames 0 –size 0 –format hdv –buffers 1000 –showstatus –timestamp /home/video/foo-
  • convert to avi format for facebook, etc.
    ffmpeg -i foo.m2t video.avi
  • convert to dv format for editing
    ffmpeg -i /home/video/foo.m2t -target ntsc-dv foo.dv

Capturing Video Over Firewire in UbuStu

Today I wanted to capture some video from mini-DV tapes using my camera, a Panasonic mini-DV model. I have done so in the past using a firewire cable, but this is the first time I’ve tried with my new Ubuntu Studio setup.

Here are the steps to follow:

1. In “Ubuntu Studio Controls,” check “enable raw1394 access.” If you try to use your firewire device now, it may crash the machine, so you should reboot before proceeding. I had the system freeze up on me two or three times before I had everything working reliably (this may be a result of the wonky firewire connection on my camera, which seems to be loose).

2. After the reboot, put the camera into VCR mode and press play. Then run Kino (from a terminal as root) and switch to capture mode. You should see the video playing in the Kino window. Rewind the tape again before you proceed. This step seems to be necessary in order to get Ubuntu Studio to recognize the camera as a firewire device (dvgrab may work just as well).

3. If you aren’t capturing a whole tape, you could just use Kino to control the camera and capture the clips. I actually prefer to do the capture from the command line using dvgrab.  To begin capture, enter this command (again as root):

#dvgrab –autosplit –frames 0 –size 0 –format raw –timestamp <dest>/<foo>

In this command, <dest> is the place you want to store the clips (e.g. /home/video), and
<foo> is whatever prefix you want the resulting filenames to have (e.g. tape1-). The clips will automatically be split into files and the timestamp will follow the prefix in each name.

Once you run the dvgrab command, it will wait for you to press play on the camera and begin capturing the clips. You’ll have to press <ctrl>-c once the clips are finished being captured.

Because of the broken firewire connection on my camera, I investigated the possibility of using USB to capture video, but that doesn’t appear to be a viable choice (and much slower, even if one could get it to work).

More info on firewire in Ubuntu here: Firewire – Community Ubuntu Documentation