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• SRT protocol not found - Raspbery Pi 4 via ffmpeg

  12 août 2021, par Tim Martin

  We tried to stream from a rasp Pi 4 via SRT, but we got a error : "protocol not found". Our command line is :

  


  ffplay srt://127.0.0.1:9500?mode=listener&latency=20000


  


  We tried the following guides :
https://trac.ffmpeg.org/wiki/CompilationGuide/Ubuntu
how to compile ffmpeg with enabling libsrt
https://www.undergroundnews.dk/index.php/item/107-rtmp-eller-srt-streaming

  


  Those guides worked so far and compiled but we still got the error message.

  


  Do you have any ideas how to get the srt protocol working on a pi via ffmpeg ?

  


• Code library for image processing [on hold]

  1er septembre 2014, par user3928079

  Dear Stack Overflow Users,

  I am looking to create my programming portfolio as a graduate of Kennesaw State University by July 2015, when I graduate. I want to create at least 3 cross platform programs related to video or animation. In the package there will be a program for playing video and music files, a program for converting video and music files, and either a program upscaling video and image files or a program that helps animators create animation like Flipbook Pro. Since Java is cross platform, and Java is the language I’m more comfortable with, I’ll develop the software in Java, unless of course Python is cross platform as well. May you please recommend me some image processing libraries that will help me accomplish the development of these types of software programs. For the upscaling program, an upscaling algorithm from BenVista called S-Spline Max is needed, especially since I want to preserve the detail of the image, because in upscaling, you are unable to gain new information from the original information. What are some good image processing libraries I can use. I know of OpenCV, but what do a lot of programs use, high profile or low profile, like Adobe Premiere Pro or Davinci Resolve. FFMPEG is a good video library, but can it easily accomplish what I need ? What are some others that can help me in my 11 month long quest ?

  Regards,

  Jordan White

• Is there an efficient way to use ffmpeg to perform a large quantity of cuts from a single file ?

  16 mars 2024, par Giuliano Oliveri

  I'm trying to cut video files into smaller chunks. (each one being one word said in the video, so they're not all of equal size)

  


  I've tried a lot of different approaches to try to be as efficient as possible, but I can't get the runtime to be under 2/3rd of the original video length. That's an issue because I'm trying to process 400+ hours of video.

  


  Is there a more efficient way to do this ? Or am I doomed to run this for weeks ?

  


  Here is the command for my best attempt so far

  


  ffmpeg -hwaccel cuda -hwaccel_output_format cuda -ss start_timestamp -t to_timestamp -i file_name -vf "fps=30,scale_cuda=1280:720" -c:v h264_nvenc -y output_file


  


  Note that the machine running the code has a 4090
This command is then executed via python, which gives it the right timestamps and file paths for each smaller clip in a for loop

  


  I think it's wasting a lot of time calling a new process each time, however I haven't been able to get better results with a split filter ; but here's the ffmpeg-python code for that attempt :

  


  Creation of the stream :

  


  inp = (
    ffmpeg
    .input(file_name, hwaccel="cuda", hwaccel_output_format="cuda")
    .filter("fps",fps=30)
    .filter('scale_cuda', '1280','720')
    .filter_multi_output('split')
)


  


  Which then gets called in a for loop

  


  (
    ffmpeg
    .filter(inp, 'trim', start=row[1]['start'], end=row[1]['end'])
    .filter('setpts', 'PTS-STARTPTS')
    .output(output_file,vcodec='h264_nvenc')
    .run()
)