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• Audio issue : only blip heard when playing video clip in Openshot and Melt

  10 octobre 2014, par MatchPoint

  The issue is identical in openshot and melt. When a clip begins play, only a blip of the clip’s sound is heard and then silence. If I export the video in openshot, only the blip is heard in the exported video which means I can no longer create videos with openshot. :^(

  The issue started around the time when I needed to rotate a clip. I had download ffmpeg and some ffmpeg plugins to do this :

  sudo add-apt-repository ppa:jon-severinsson/ffmpeg
  
  sudo apt-get update
  
  sudo apt-get install ffmpeg
  
  sudo apt-get install frei0r-plugins

  I removed ffmpeg and frei0r-plugins and then reinstalled openshot but no luck. I feel my last option is to reinstall Ubuntu which I haven’t been forced to do in years.

  I’m sure this is a codec issue but I don’t know how to debug the issue. Some threads mention libslt as a possible issue if melt can’t play the audio in the clip. Anyone else have any suggestions ?

  Ubuntu 14.04
  Openshot 1.4.3
  melt 0.9.0

  Clip details - Container : Quicktime, Video codec h.264, audio codec mpeg-4 aac

  Also, the "Videos" app has no problem playing the audio in the clips.

  Thanks !

• Making a blu-ray video-album from 30fps video-recordings ?

  11 janvier 2015, par mr_lou

  I wish to make a blu-ray video-album with all the family video-recordings I’ve done with various recording devices through-up the years. Most of the recordings are 720p 30fps, recorded with my cellphone.

  As many others before me I have now learned, that simply saving my video-project as a 720p 24fps rendering, results in a lot of jerkiness due to the missing frames. Not good.

  But what to do then ?

  According to http://en.wikipedia.org/wiki/Blu-ray_Disc#Media_format my other framerate options for 720p are 60fps (59.94fps) or 50fps. So as I’m writing this I’m trying to render my project into a 59.94fps video. Logically, if my recordings have 30fps, there’ll be a little jerkiness here too though ?

  Another option I seem to have, is to save my project as a 1080i 29.97fps video. This is as close to the 30fps I can get, but again : 29.97fps isn’t 30fps, so what happens with jerkiness here ?

  Also, saving my 720p 30fps recordings as either 720p 59.94fps or 1080i 29.97fps logically results in a bigger filesize. Filesize is somewhat important too, as I expect this blu-ray collection to contain as many videos as possible. (720p recordings should give at least 11 hours on a standard 25gb blu-ray disc).

  And finally, there’s also the theoretical option of converting my 30fps recordings to smooth 24fps recordings, but as far as I can understand in my searches, this is extremely tricky / almost impossible to do ?

  Surely it can’t be this tricky to put everyday recordings onto a blu-ray disc ? I must be missing something ?

  The overall question is : What is the best solution for putting 720p 30fps and 1080p 30fps video-recordings onto a blu-ray disc ?

  Thanks !

  EDIT :

  Two possible answers I’m expecting to hear :

  1) Best practice to put 720p 30fps and 1080p 30fps videos onto a blu-ray, is to just stick to 720p 30fps and 1080p 30fps. Although it is not a blu-ray standard, the majority of players will play them anyway.

  2) Best practice is to use 720p 59.94fps. That’s the only way to make sure the video plays on most devices. There are simply too many devices that will only play the blu-ray standards. So you can forget about using anything else.

• Evolution of Multimedia Fiefdoms

  1er octobre 2014, par Multimedia Mike — General

  I want to examine how multimedia fiefdoms have risen and fallen through the years.

  
  
  

  Back in the day, the multimedia fiefdoms were built around the formats put forth by competing companies : there was Microsoft/WMV, Apple/MOV, and Real/RM as the big contenders. On2 always wanted to be a player in this arena but could never quite catch a break. A few brave contenders held the line for open source and also for the power users who desired one application that could handle everything (my original motivation for wanting to get into multimedia hacking).

  The computer desktop was the battleground for internet-based media stream. Whatever happened to those days ? Actually, if memory serves, Flash-based video streaming stepped on all of them.

  Over the last 6-7 years, the battleground has expanded to cover mobile devices, where Flash’s impact has… lessened. During this time, multimedia technology pretty well standardized on a particular stack, namely, the MPEG (MP4/H.264/AAC) stack.

  The belligerents in this war tried for years to effectively penetrate new territory, namely, the living room where the television lived. This had been slowgoing for years due to various user interface and content issues, but steadily improved.

  Last April, Amazon announced their entry into the set-top box market with the Fire TV. That was when it suddenly crystallized for me that the multimedia ecosystem has radically shifted. Now, the multimedia fiefdoms revolve around access to content via streaming services.

  Off the top of my head, here are some of the fiefdoms these days (fiefdoms I have experience using) :

  • Netflix (subscription streaming)
  • Amazon (subscription, rental, and purchased streaming)
  • Hulu Plus (subscription streaming)
  • Apple (rental and purchased media)

  I checked some results on Can I Stream.It ? (which I refer to often) and found a bunch more streaming fiefdoms such as Google (both Play and YouTube, which are separate services), Sony, Xbox 360, Crackle, Redbox Instant, Vudu, Target Ticket, Epix, Sony, SnagFilms, and XFINITY StreamPix. And surely, these are probably just services available in the United States ; I know other geographical regions have their own fiefdoms.

  What happened ?

  When I got into multimedia hacking, there were all these disparate, competing ecosystems. As a consumer, I didn’t care where the media came from, I just wanted to play it. That’s what inspired me to work on open source multimedia projects. Now I realize that I have the same problem 10-15 years later : there are multiple competing ecosystems. I might subscribe to fiefdoms X and Y, but am frustrated to learn that something I’d like to watch is only available through fiefdom Z. Very few of these fiefdoms can be penetrated using open source technology.

  I’m not really sure about the point about this whole post. Multimedia technology seems really standardized these days. But that’s probably just my perspective because I have spent way too long focusing on a few areas of multimedia technology such as audio and video coding. It’s interesting that all these services probably leverage the same limited number of codecs. Their differentiation comes from the catalog of content that each is able to license for streaming. There are different problems to solve in the multimedia arena now.