Recherche avancée

Sur d’autres sites (8344)

• Which approach is the best and fastest for video conversion from x (MOV, AVI etc) to x type (MP4, MP2 etc)

  18 avril 2017, par user2224250

  At the moment, I am using ffmpeg library to convert videos from x type (MOV, AVI etc) to dedicated type i.e. MP4. But it is taking too long time for video conversion. Lets say the MOV video size is 1.8GB and the conversion takes approximately 1 hour 30 minutes. Is there any other way to reduce the conversion time duration with maintaining the same quality ?

  My FFMPEG syntax as follows for video conversion :

  • ffmpeg -y -i input.mov -vcodec h264 -acodec aac -strict -2 out.mp4

  How to acheieve fast video conversion ?

  • what about the output format changed to MPEG2 or others ?
  • Is there any other fast codecs other than h264 ?
  • What are the best compression techniques ?

  Any pointers would be really appreciable.

• avutil/hwcontext_vulkan : Improve type-safety

  14 septembre 2023, par Andreas Rheinhardt

  avutil/hwcontext_vulkan : Improve type-safety
  The AVBuffer API uses uint8_t as base type for buffers
  
  and therefore its free callbacks need to abide by this.
  
  Therefore vulkan_frame_free() used an inappropriate signature
  
  which caused casts whenever this function has been called
  
  manually.
  This commit changes this by making vulkan_frame_free()
  
  use the proper type and a vulkan_frame_free_cb() that
  
  is used as free callback for the AVBuffer API.
  Reviewed-by : Lynne <dev@lynne.ee>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavutil/hwcontext_vulkan.c

• Identification of Frame Type using Xuggle

  1er décembre 2012, par Samveen

  I'm trying to extract just the I-Frames from a video using the Xuggle API. I took the first example from the Xuggle source from here and removing the display code, added the following code snippet to identify the frame type of the current frame :

  //    Decode loop {
  
            if (picture.isComplete()) {
  
                com.xuggle.xuggler.IVideoPicture.PictType type = picture.getPictureType()
  
                if(type == com.xuggle.xuggler.IVideoPicture.PictType.I_TYPE)
  
                    System.out.println("(I-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.B_TYPE)
  
                    System.out.println("(B-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.P_TYPE)
  
                    System.out.println("(P-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.S_TYPE)
  
                    System.out.println("(S-Frame)\n");
  
                else if(type ==com.xuggle.xuggler.IVideoPicture.PictType.DEFAULT_TYPE)
  
                    System.out.println("(Default)\n");
  
                else
  
                    System.out.println("(Other)\n");
  
            }
  
  //    }

  Using this code, I never get an I-Frame in my test video, which by definition of being it being a video is impossible (every video's first frame MUST be an I-Frame) and every frame is identified as

  When I use mplayer to extract the I-Frames from the same video using :

  mplayer video20.mp4 -benchmark -nosound -noaspect -noframedrop -ao null \
  
          -vo png:z=6 -vf framestep=I

  I correctly get a set of I-Frames.

  The number of frames displayed by my code is identical to that extracted by mplayer without the framestep filter

  mplayer video20.mp4 -benchmark -nosound -noaspect -noframedrop -ao null \
  
          -vo png:z=6

  The input video in question is an H264 encoded video.

  My question is that what can I do to correctly get the I-Frames from the video using xuggle

  I picked up the method from Java - Keyframe extraction from a video