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• Using explicit casting to solve invalid conversion from ‘int’ to ‘AVRounding’

  29 juillet 2020, par C4RN4GE

  I'm trying to follow the "learn ffmpeg the hard way" guide on github (https://github.com/leandromoreira/ffmpeg-libav-tutorial#chapter-2---remuxing) and when I try to run the remuxing code for myself using a C++ compiler I always get the error

  


  invalid conversion from ‘int’ to ‘AVRounding’[-fpermissive]


  


  The only real difference between my code and the github original is that I take the input filename and output filename as parameters instead. Doing some resarch I have found that AVRounding is a enum ? I think ? Thus I need to explicitly cast somehow. However I'm failing to understand how explicit casting works and how I would use it to solve my issue. Where would I cast it ?
Here's the line that causes the issue :

  


  packet.pts =  av_rescale_q_rnd(packet.pts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
packet.dts =  av_rescale_q_rnd(packet.dts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);


  


  Could anyone explain how to solve the issue ? Sorry if it's a beginners mistake. Thanks in advance for any help.

  


• How to screencast the background video

  24 décembre 2013, par quartz

  I am playing two videos at the same time. One video is on the top of another video. I want to screen cast the background video. How to do that ?

• FFmpeg - Rotating at angle

  23 septembre 2017, par connor

  I’ve been working through FFmpeg, but I have been unable to get a rotation to run from the examples they have on their site. I am trying to "wiggle" a video back and forth at a fixed point on the bottom - think a head moving left to right (and so on).

  I am attempting to do this with the filter "rotate" (https://ffmpeg.org/ffmpeg-filters.html#rotate). Attempting to use their examples, I get an error.

  This is what I have so far :

  ffmpeg -i vid1.mp4 -i vid2.mov -loop 1 -i image.png -filter_complex "\
  
      [2:v]alphaextract, scale=240x160[mask];\
  
      [0:v] scale=240x160, rotate=A*sin(2*PI/T*t) [ascaled];\
  
      [ascaled][mask]alphamerge[masked];\
  
      [1:v]scale=480x360[background];\
  
      [background][masked]overlay=120:20"\
  
      -c:a copy 65B6354F61B4AF02_HD_sq.MOV

  I am using "rotate" directly from an example in an attempt to get something to run at all.

  The error I get back is :

  [Parsed_rotate_3 @ 0x7ff4476045e0] [Eval @ 0x7fff5b3e3f00] Undefined constant or missing '(' in 'T*t)'
  
  [Parsed_rotate_3 @ 0x7ff4476045e0] Error occurred parsing angle expression 'A*sin(2*PI/T*t)'
  
  [Parsed_rotate_3 @ 0x7ff4476045e0] Failed to configure output pad on Parsed_rotate_3
  
  Error reinitializing filters!
  
  Failed to inject frame into filter network: Invalid argument
  
  Error while processing the decoded data for stream #1:0

  If I remove ’A’, ’T’, ’sin’, etc, rotate does actually work, but far from the desired behavior.

  Am I missing something to expose those params ?