Recherche avancée

Sur d’autres sites (5765)

• FFmpeg H.264 NVENC - high444p profile not working at 1920x1080 via library but works via command line encoding

  10 décembre 2024, par Vivek Nathani

  I am building a real-time desktop streaming application in Rust and I am using FFmpeg (H.264 NVENC) to encode the raw frames captured as BGRA from desktop.

  


  I am able to get it to work on profiles such as baseline, main, and high but nothing seems to be working on high444p which is what I need to do 4:4:4 chroma subsampling.

  


  Below is the setup I have for constructing the encoder. I am using the rust-ac-ffmpeg crate to do this.

  


  builder = builder
    .pixel_format("bgra")
    .height(1080)
    .width(1920)
    .set_option("profile", "high444p")
    .set_option("preset", "medium")
    .set_option("tune", "hq")
    .set_option("b:v", "30M")
    .set_option("maxrate", "30M")
    .set_option("bufsize", "60M")
    .set_option("framerate", "60")
    .set_option("pix_fmt", "yuv444p");


  


  No matter what combination of settings I try, I always get a single line error as follows :

  


  [h264_nvenc @ 0000020bf69f6680] InitializeEncoder failed: invalid param (8): Invalid Level.


  


  I have also tried adding levels explicitly. Have tried 4.1, 4.2, 5.1, 5.2, 6.1 and 6.2.

  


  The only case where this does work is if the resolution is low, let's say around 500x500 or 600x800. But this is not suitable for my usecases.

  


  Moreover, the equivalent command for this just works right out of the box. On the same machine. Same ffmpeg version. Running this command on an output.raw file which is just a dump of the frames captured by my screen capture mechanism.

  


  ffmpeg -f rawvideo -pix_fmt bgra -s 1920x1080 -framerate 60 -i input.raw -c:v h264_nvenc -preset p1 -profile:v high444p -pix_fmt yuv444p -b:v 30M -maxrate 30M -bufsize 60M output.mp4


  


• avcodec/libfdk-aacdec : set keyframe flag and profile in output frames

  17 novembre 2024, par James Almer

  avcodec/libfdk-aacdec : set keyframe flag and profile in output frames
  Don't depend on the generic code setting this.
  
  This is in preparation for a following change.
  Signed-off-by : James Almer <jamrial@gmail.com>
  

  • [DH] libavcodec/libfdk-aacdec.c

• Correct Complex Lens Distortion in FFMPEG (or OpenCV) [closed]

  29 septembre 2024, par C.M.

  I need to process videos which were taken with a wide angle vehicle camera. A good example is this frame from a video :

  


  

  


  As you can see, the image is pretty distorted and I need to correct that. After some research, neither a Barrel distortion or a Pincushion distortion is the case here. I'd say it depends on the axis. The x axis seems to have a Pincushion distortion, but the y axis seems to have a Barrel distortion.

  


  In my project I use a Java backend and I use FFmpeg to process the videos (re-encoding, color correction, ...). Therefore I'd like to do this in FFmpeg as another video filter.

  


  I tried to use the lenscorrection filter but couldn't find any suitable values for k1 and k2. IMHO this isn't even possible since the filter can only handle the two types of distortion mentioned above. Here are two examples where I tried to correct the horizontal and vertical elements of the image :

  


  

  


  (with k1= -0.7, k2=0.4)

  


  

  


  (with k1=0.7)

  


  But the resulting image would need to look like this (just roughly edited with GIMP) :

  


  

  


  Is this even possible with FFmpeg filters ? I already tried out the v360 filter (similar like in this article) but just achieved similar results.

  


  If I'm correct this isn't possible with video filters. So I thought of doing this in OpenCV in Java by extracting all the frames with FFmpeg, transforming them with OpenCV and rendering them to a video again. Unfortunately I have no experience with OpenCV and couldn't get any results. I think this should be possible in some way.

  


  Can someone help me ?