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• Video processing / playback with alpha channel in C# or C++ [closed]

  2 avril 2013, par Corylulu

  WHAT I'M AFTER

  I've been exploring the best ways to do this, but seem to keep running into hiccups when trying to playback video and then grab the frame with an alpha channel (ARGB) to then be further manipulated.

  I've gotten everything to work with AForge to then find out that the Alpha gets stripped out during the process. I considered OpenCV, but the Emgu CV has a different license that I can't use and I can't verify that OpenCV can read Alpha channels as well.

  I looked into FFMPEG .NET wrappers, but haven't found any that are out of their alpha phase or have a license I can use them with (since this could be used for commercial purposes and can't be open sourced)

  So I'm looking for a library that is preferably C# or C++ that can play a .MOV or .AVI while preserving it's alpha channel when I make it into a Bitmap.

  SUMMARY [TL ;DR]

  I'm looking for library / sample code

  • Written preferably in C#, C++ as a fallback. Hopefully easy enough to use.
  • Can playback AVI and MOV files
  • Will preserve the alpha channel
  • Will allow me to access each frame's ARGB values directly
  • Preferably something that uses the FFMPEG library since it's able to read most formats I need

• 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.

• perturbation of an audio/video decoding execution trace with gstreamer

  9 mars 2013, par KKc

  I am a new comer in gstreamer community and i have a pipeline to decode and trace a .mp4 file.

  gst-launch --gst debug=filesrc:7,queue:7,audioconvert:7,audioresample:7,qtdemux:7,faad:7,ffmpeg:7,audioresample:7,audioconvert:7,autoaudiosink:7,autovideosink:7,  filesrc location=...! qtdemux name=demuxer demuxer. ! queue ! faad ! audioconvert ! audioresample ! autoaudiosink demuxer. ! queue ! ffdec_h264 ! ffmpegcolorspace ! autovideosink > file1

  I inserted the "identity" component to disturb the decoding, and effectively, i saw images which became very slow and sound disappeared.
  I used this command :

  gst-launch --gst debug=filesrc:7,queue:7,audioconvert:7,audioresample:7,qtdemux:7,faad:7,ffmpeg:7,audioresample:7,audioconvert:7,autoaudiosink:7,autovideosink:7,  filesrc location=...! qtdemux name=demuxer demuxer. ! queue ! faad ! audioconvert ! audioresample ! autoaudiosink demuxer. ! queue ! identity sleep-time=1000000 ! ffdec_h264 ! ffmpegcolorspace ! autovideosink > file2

  The first time i did this execution, two new functions appeared in file2,

  (i) gst_ffmpegdec_chain...'skipping...',

  (ii) gst_ffmpegdec_video_frame...'Dropping..'

  I assumed that the meaning is that some data were dropped or something else

  However, since many days, i use the same pipelines, with the same video to decode ; i obtain the same bad visualization, but any new function in file 2 :(
  the only difference is the number of occurrence of the functions below :

  *gst_ffmpegdec_update_qos :...'update* 558 times in one case

  *gst_ffmpegdec_update_qos :...'update* 4 times in the other case

  I don't know why i am unable to produce again a disturbed trace with 'skipping..' and 'dropping..'

  My questions are :

  1- have you any idea about the meaning of the above functions ?

  2- Do you know any other component useful to disturb a A/V decoding processing ?

  Thank you for any reply