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• ffmpeg : convert a video by using another video's settings

  11 janvier 2015, par orcaman

  I have an mp4 file containing an H.264 video. This video has particular settings that I am not sure about, but I want to reproduce them on other videos that I encode (those other videos are already H.264 encoded, but they have different properties - bitrate, size, etc.)

  I know that ffprobe can be used to extract some information from the original video, and I guess that using this information I could try to reproduce the conversion settings required for use with other videos.

  Question is : do I have to do this manually, in the sense that I need to map the output of ffprobe to ffmpeg flags ? Is there a better way to do this, to make sure I don’t miss anything ?

• 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.

  


• OpenCV or FFMpeg Python - how to combine portions of two video files into one video file ?

  1er juin 2018, par James Johnson

  Using Python, how does one combine two video files and then save into one video file ?

  For example :
  I want to combine 0:15 to 0:30 of A.mp4 with 0:10 to 0:20 of B.mp4 to create C.mp4.

  How does one do this in Python ?

  Thank you !