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• Using FFmpeg, How to convert an frame image sequence to video(video codec : dvvideo) ?

  25 mai 2022, par ruping

  I'm working on an image processing project.

  


  The project proceeds as follows :

  


  Input Video -> frame Sequence -> (Processing) -> Output Video

  


  I want to create the output video with the same specifications as the input video.

  


  The specs of the input video we use are :

  


  - Size : 1280x1080, Codec : dvvideo, pixel_fmt : yuv422


  


  But I am struggling with the following error :

  


  Duration: 00:00:03.20, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: png, rgb24(pc), 1280x1080 [SAR 3:2 DAR 16:9], 29.97 fps, 29.97 tbr, 29.97 tbn, 29.97 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (png (native) -> dvvideo (native))
Press [q] to stop, [?] for help
[dvvideo @ 0x55b965b745c0] DVCPRO HD encoding is not supported.
[dvvideo @ 0x55b965451780] ff_frame_thread_encoder_init failed
Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
Conversion failed!


  


  The code is below. (subprocess in python)

  


  ffmpeg -y -f image2 -r "{fps}" -i {input_img_root} -s 1280:1080 -b:v {bit_rate}  -vcodec dvvideo -pix_fmt yuv422p "{output}"


  


  (fps and bitrate are taken from the input video. and input_img_root and output are paths.)

  


  I've been trying for several days, but it doesn't work.

  


  If you know any way to make a new video while maintaining the video specifications (Especially dvvideo codec)(not using ffmpeg), it would be nice to share it.

  


• movenc : Write correct presentation timestamps in tfra

  11 octobre 2014, par Martin Storsjö

  movenc : Write correct presentation timestamps in tfra
  Previously we wrote decoding timestamps here, while the specs
  
  say it should be presentation timestamps.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] libavformat/movenc.c
  • [DH] libavformat/version.h

• Why can’t VLC go in to fullscreen mode ?

  31 mai 2017, par matiastofteby

  I’m working on a Matlab application that uses a VLC class to control a VLC-instance. One of the features is to set the VLC player to fullscreen. This feature works perfectly fine.

  The VLC player is downloaded from Matlab’s File Exchange : https://se.mathworks.com/matlabcentral/fileexchange/56215-vlc (Thanks a lot Léa Strobino)

  However, one particular clip insists on resizing the player to a smaller size.
  I have done some research and it turns out that this is a common problem in some VLC versions.

  Normal workarounds are to uncheck the “adapt interface to video size” (something like that) and to check the “Fullscreen” box.
  This ought to make the player open in fullscreen and not resize the screen to video size. The video still resizes the player to a smaller size.

  All the specs of the clips are the same : Same file extension (.vob), formats and were made the same way (I did some video trimming and such using ffmpeg – but the same way every time).

  I have noticed one difference and that is that this particular video has a lower Data and bitrate ( 1000-1500kbps) where as the others are higher (<4000kbps). Also when showing the properties of the clip the frame height and width are blank as opposed to the others that have specific values.

  This should however not have an effect of the fullscreen command from Matlab called after loading the video into the playlist. The command has no effect on this video, but does on all other.

  It is possible to set the player to fullscreen manually by clicking the window, so it is not caused by some restriction in the video not allowing it to fullscreen.

  Why does the video refuse to go in to fullscreen ?

  Hope somebody is able to help.