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• Preview video in android before saving to phone

  13 novembre 2014, par Zoe

  I’m in the process of creating a video editor for android.
  I am loading .mp4 videos into a timeline, where each rectangle in the timeline represents an imported video and I can drag/drop and rearrange these videos etc before saving the new .mp4 to my phone.

  I’ve been using mp4parser to do this, however I have ffmpeg loaded too but have avoided using this as I’m not too familiar with c++

  I have a space for a video player in my app. The idea is to have a seek line that can be dragged along the timeline as you are editing, and I want the player to be able to play a
  the edited video at the given point.

  However, the only examples on how to implement video players in android require you to load this video from your phone to play it. I was thinking I could just play the loaded videos separately but one after another giving the impression you’re watching a whole video, but I’m later planning to add functionality to include transitions and subtitles to videos which you would not be able to preview using this method.

  Any ideas on how about I can go about implementing a video player to preview the media whilst editing ?

  Thank you.

• How do I make a C# win form program that breaks a video down to frames, then put those frames back together to make a video ?

  30 juillet 2015, par Atom Scott

  First, I’m fairly new to C sharp so I’m looking for a thorough and easy to understand answer.

  How do I make a C# win form program that breaks a video down to frames, then puts those frames back together to make a video ?
  I also want to be able to select which frames to extract by setting an interval time. For example, extract frames that are one second apart.
  Is this possible, I have done some research but I don’t understand how to use the codes displayed on the following websites.

  Supposedly code to breakdown video into frames. However I do not know where to put it. Do I make it the event for a button or something. From my own research I am guessing this uses ffmpeg. But I’m not exactly sure how to use ffmpeg, I have tried downloading Aforge, and use Aforge.Video.ffmpeg. But I’m stuck there.
  http://www.researchgate.net/post/Has_anyone_code_in_C_to_read_video_file_and_split_it_into_frames[^]

  Code for making a video from images, it looked promising so i tried to copy and paste it visual studio. However the line using BytescoutImageToVideoLib ; has an error asking me whether I am missing a reference. What reference am I missing ?
  http://bytescout.com/products/developer/imagetovideosdk/imagetovideosdk_first_step_with_visual_c_sharp_net.html[^]

  I also noticed that there was a page on code project for something similar to this, but the downloadable demo project didn’t work at all. I didnt see the point in spending time on something where the end product is broken.
  http://www.codeproject.com/Articles/13237/Extract-Frames-from-Video-Files

  Any help is greatly appreciated.

• Using ffmpeg rtmp stream a static image and audio input [on hold]

  30 octobre 2017, par Chad

  Using a Raspberry Pi, stream audio in and use a static image as the video input thru ffmpeg over RTMP to a Cloud video provider (DaCast in this instance)

  So far, I’ve gone through many blog posts, Stack Overflow questions, and package documentation. I’ve found that most of the posts are no longer valid with the newer versions of ffmpeg. Or don’t quite line up with what I am trying to achieve.

  However, I have figured out the right settings to stream the Raspberry Pi Camera v2 with the audio in.

  ffmpeg \
    -f alsa -ac 1 -i plughw:1,0 \
    -f v4l2 -s 1920x1080 -r 30 -input_format h264 -i /dev/video0 \
    -vcodec copy -preset veryfast -r 15 -g 30 -b:v 64k -ar 44100 -threads 6 -b:a 96k -bufsize 3000k \
    -f flv rtmp ://streaming_server_url
  

  But can’t seem to get it right to replace the video input with a static image.

  I have tried removing the 3rd line and adding -loop 1 -i '/path/to/image.jpg'

  The logs look like :

  [alsa @ 0x55e4b980] Thread message queue blocking ; consider raising the thread_queue_size option (current value : 1024)
  [alsa @ 0x55e4b980] ALSA buffer xrun.  0kB time=00:00:00.00 bitrate=N/A speed=   0x
  [alsa @ 0x55e4b980] ALSA buffer xrun.130kB time=00:00:00.27 bitrate=3822.5kbits/s speed=0.0403x
  ...
  

  I have also tried looping a 4 second video, with similar outcomes.

  ---

  My Setup for context :

  • Raspberry Pi 3 Model B
  • USB Audio Device (Sabrent USB External Stereo Sound Adapter)
  • Ubuntu MATE 16.04.2 (Xenial)
  • ffmpeg version 3.2-2+rpi1 xenial1.7 (I can post what is configured with the build, if needed)