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• Overlaying video with ffmpeg

  11 novembre 2012, par elee

  I'm attempting to write a script that will merge 2 separate video files into 1 wider one, in which both videos play back simultaneously. I have it mostly figured out, but when I view the final output, the video that I'm overlaying is extremely slow.

  Here's what I'm doing :

  1. Expand the left video to the final video dimensions

     ffmpeg -i left.avi -vf "pad=640:240:0:0:black" left_wide.avi

  2. Overlay the right video on top of the left one

     ffmpeg -i left_wide.avi -vf "movie=right.avi [mv] ; [in][mv] overlay=320:0" combined_video.avi

  In the resulting video, the playback on the right video is about half the speed of the left video. Any idea how I can get these files to sync up ?

• Trouble with CoCCA Registry

  7 octobre 2012, par Multimedia Mike — General

  I’ve been rather despondent all week. People who see me daily could readily identify this fact. Unfortunately, the exact reason was difficult to adequately explain. The problems that nerds deal with…

  When A Domain Expires
  As a few people noticed, the multimedia.cx domain and all of it’s subdomains didn’t work this last week. The problem started on Monday, October 1. Whose fault ? Well, fundamentally, I neglected to renew the domain name in time. However, I prefer to place the blame on the .cx domain registrar, CoCCA Registry. You see, they have never developed the technology to email a domain holder with a notice that their domain is about to expire or has already expired.

  This domain is the only one I have ever held so I don’t have a lot of experience in this matter. I wondered if I was crazy for thinking it would be normal for a registrar to send an email or 2 with status updates about your domain. I get the impression from speaking with others that this is indeed normal. I have 3 different email addresses listed under my account at the registrar– 2 at multimedia.cx and a backup gmail account. I checked spam folders after this incident. Then I remembered that I have never received any email notifications from them (although password reset emails show up, so that part thankfully works). Also, their support emails are black holes.

  So, I guess the moral is : be wary of dealing with CoCCA Registry. However, they seem to be the only way to register domains under a wide variety of uncommon country codes.

  By Friday, the domain appeared to have been reinstated, even through the status was officially listed as “renewal-pending” according to the web-based management console. Eventually, as cached DNS results started to time out throughout the day, I started seeing subdomains come back. I excitedly used the ‘dig’ command to count down the seconds until gamemusic.multimedia.cx was accessible on the network I was on (the number after the domain name is the time-to-live or ‘TTL’ value) :

  $ dig +nocmd gamemusic.multimedia.cx +noall +answer
  gamemusic.multimedia.cx. 3      IN      A       174.143.152.251
  $ dig +nocmd gamemusic.multimedia.cx +noall +answer
  gamemusic.multimedia.cx. 2      IN      A       174.143.152.251
  $ dig +nocmd gamemusic.multimedia.cx +noall +answer
  gamemusic.multimedia.cx. 1      IN      A       174.143.152.251
  $ dig +nocmd gamemusic.multimedia.cx +noall +answer
  gamemusic.multimedia.cx. 12962  IN      A       207.45.186.114
  

  Finally, today (Saturday), I received a receipt confirming that the domain has been renewed.

  8 Years Old
  Incidentally, happy eighth birthday to multimedia.cx. It was September, 2004 when I decided to branch out from a simple ISP-based web presence.

  People often ask why I went with the .cx TLD. When I decided I wanted a proper domain name 8 years ago, I found that multimedia.X was already taken for just about every TLD value of X. .cx was a notable exception and was distinctive enough (speaking of .X, though, I see that multimedia.xxx is still up for grabs as of this writing ; I imagine that would come with a whole other set of problems).

  It’s funny that tech nerds often rail against outsourcing too much — email, storage, computing power, web hosting — all to some type of cloud provider under the premise that it could easily be taken away. But this episode teaches me that even having your own domain name is no guarantee of a solid online presence.

  Meanwhile, I have taken proactive steps to avert this same situation from arising again :

  
  
  

  Barring a lack of automated emails from the registrar, I hope a Google Calendar reminder set up a month ahead of expiration will do the trick.

• FFMpeg creates MP4 which no browser can decode, but it can be played in VLC

  21 octobre 2013, par wvxvw

  How can I debug what happened ? I've tried this with variations to generate a short video from a single image :

  ffmpeg -loop 1 -i black.png -vcodec libx264 -b 1500k -s 640x360 -t 1 out.mp4

  tried :

  1. Changing aspect ration (or omitting it).
  2. using -image2 instead of -loop.
  3. omitting bitrate.
  4. creating longer videos.
  5. also tried different syntax for specifying video codec : -v:c libx264.
  6. tried mpeg instead of libx264.

  In every case the effect is the same. The video plays in VLC, but not in the browser.