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• Using Qt Media Player on Raspberry Pi 1

  18 mai 2015, par Mauker

  I have a project built using Qt5 which has to play a video. Just like in the videowidget sample code.

  I’ve followed these instructions to build qt5 on my Pi. And it went just fine. But when I try to run any qt program that uses QMediaPlayer, I get the error message :

  defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.mediaplayer"

  Which means I don’t have a backend to play the video, right ? Is there any one that I can use which will with Qt, like ffmpeg ? And how can I get it to work ? Specially for h264 videos.

  I’ve tried to install gstreamer as is told on this link, but it’s not working. Will I have to rebuild the entire qt5 again ?

  P.S. : I have the raspberry pi 1 model B with raspbian installed.

  Edit : As mentioned by Greenflow, I checked the ./configure log and saw that the GStreamer was compiled in, but the video apps are still not working...

  The message on the log was like this :

  GStreamer .............. yes (0.10)

  And the message on Greenflow’s log was like this :

  GStreamer .............. yes (1.0)

  Clearly it’s another version of GStreamer, but is it the problem ?

  I’ve also found this post which says QtMultimedia on the Pi is rather useless, but the post is from 2013, so I’m not sure if it’s really relevant. I’d like to have this app playing hardware accelerated videos on my Raspberry Pi, but I’m almost dropping the idea.

  Anyways, thanks Greenflow for the head start.

  Edit 2 : Found this thread on the Qtcentre. Damn, this thing is not going to be easy to solve, I guess...

• How to stream to ffserver from android

  8 mars 2013, par kev

  I need to stream from an android camera/ file to a remote ffserver which will broadcast my video. I can do this on the desktop in ubuntu by issuing a command like :

  ffmpeg -f video4linux2 -s 640x480 -r 25 -i /dev/video0 http://192.168.0.20:8090/cam1.ffm

  or stream a file like this :

  ffmpeg -i /home/kev/share/movie.mp4 http://192.168.0.20:8090/cam1.ffm

  So basically i want to be able to do the above from android. After several searches this is what i've done so far - i came across this link http://bambuser.com/opensource from which i downloaded the ffmpeg source and built it. The build outputs several things :
  1. shared libs [libavcodec, libavcore, libavdevice, libavfilter,libavformat,libavutil,libswscale]
  2. executables [ffmpeg,ffprobe]

  Not sure how to plug my functionality with these resources this is what i've tried so far :
  1. loaded the libs in my Activity using System.loadLibrary() then copied the ffmpeg executable to the assets folder which at runtime i copied to my application's "files" directory i then set permissions for the executable using Runtime.getRuntime().exec(). then the last step was to execute it in java with the following statement :

  Runtime.getRuntime().exec("ffmpeg -i file:///android_asset/movie.mp4http://<server>:8090/cam1.ffm");
  
  </server>

  2. copied ffmpeg.c,the shared libraries and the "include" folder that was generated by the build to my jni folder and added a jni function that wraps around the main() function in ffmpeg.c. With this approach i've found myself having to copy several header files from the ffmpeg source for the ndk-build to succeed and i highly doubt if this is the way to go.

  The above two approaches havnt worked for me, i'm not sure where i'm going wrong, so any help on how to do a simple ffmpeg streaming like an mp4 file from android would be highly appreciated.

• Using command line find to encode files and save to same directory

  15 janvier 2017, par Ali Samii

  I am trying to execute a find bash command to process hundreds of video files that are all named video-original.mp4 but are in subdirectories of a parent directory.

  Here’s an example of the directory structure :

  videos
  
  ├── 01a
  
  │   └── video-original.mp4
  
  ├── 01b
  
  │   └── video-original.mp4
  
  ├── 02a
  
  │   └── video-original.mp4
  
  ├── 02b
  
  │   └── video-original.mp4
  
  ├── 03a
  
  │   └── video-original.mp4
  
  └── 03b
  
      └── video-original.mp4

  I am using the following command :

  find ./ -name 'video-original.mp4' -exec bash -c 'ffmpeg -i "$0" -f mp4 -vcodec libx264 -preset veryslow -profile:v high -acodec aac -movflags faststart video.mp4 -hide_banner' {} \;

  The problem I am having is that it is saving the file video.mp4 in the parent videos directory, instead of in the subdirectory next to the original video-original.mp4

  Afterwards, I want to delete the file video-original.mp4. Currently, my process entails waiting for all the videos to be reencoded, and then once complete, issuing a separate command to delete the file video-original.mp4 :

  find ./ -name 'video-original.mp4' -exec bash -c 'rm -rf "$0"' {} \;

  And my final step would be to extract a screenshot of the new video.mp4 at 10 seconds and save it as thumbnail.jpg. Again, I am currently doing that as a separate step that I execute after the previous two steps are completed.

  find ./ -name 'video.mp4' -exec bash -c 'ffmpeg -i "$0" -ss 00:00:10 -vframes 1 thumbnail.jpg' {} \;

  What I would like to do is combine these three steps into a single command so the end result will be :

  videos
  
  ├── 01a
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  ├── 01b
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  ├── 02a
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  ├── 02b
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  ├── 03a
  
  │   ├── thumbnail.jpg
  
  │   └── video.mp4
  
  └── 03b
  
      ├── thumbnail.jpg
  
      └── video.mp4

  Finally, it would be great to save that as a bash script and include it in my path in /usr/local/bin or ~/bin as an executable so I could just issue the command reencode and it would run. Would be even better if the input file could have any video file, for example, random_name.mp4 or random_name.mov or random_name.webm, basically any video file (but skipping video.mp4 at the encoding step).