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• download rtmp live stream video secondly

  15 juillet 2024, par Chenguang He

  I'm working on a java project to create a rtmp server and download the real-time flv video every second(need to download multiple recording frame secondly instead of download entire recording after live stream finished)
This is my logic, firstly listen to the rtmp channel to write video and audio into file

  


  if(msg instanceof VideoMessage vm){
byteArrayOutputStream = new ByteArrayOutputStream();
 byteArrayOutputStream.writeBytes(vm.getVideoData());
            File file = new File("tmp/video_" + i);
            FileOutputStream fos = new FileOutputStream(file);
            fos.write(byteArrayOutputStream.toByteArray());
            fos.close();

}


  


  Then decode to H264 to get playable flv file

  


  FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(input);
grabber.setFormat("h264");
        grabber.start();
FFmpegFrameRecorder recorder = new FFmpegFrameRecorder(outputFilePath, grabber.getImageWidth(), grabber.getImageHeight());
recorder.start();
while ((frame = grabber.grab()) != null) {
            recorder.record(frame);
        }
grabber.stop();
        grabber.release();
        recorder.stop();
        recorder.release();
}


  


  But this login was failed. I met this issue when I implemented the ffmpeg

  


  data partitioning is not implemented. Update your FFmpeg version to the newest one from Git. If the problem still occurs, it means that your file has a feature which has not been implemented.


  


  Is there any other idea to solve this or other way to achieve the logic ? Thanks

  


• How to Download YouTube Videos in 1080p with English Subtitles Using yt-dlp with Python 3

  30 juillet 2024, par edge selcuk

  I am trying to download YouTube videos using yt-dlp in Python 3.9. I want to download videos in 1080p quality and if 1080p is not available, it should download the best available quality. The audio and video files should be merged into a single MP4 file, and I have ffmpeg installed to handle the merging process.

  


  Here is my script :

  


  import os
import sys
from yt_dlp import YoutubeDL

def download_video(url):
    output_dir = r"/path"  # Update this path

    # Ensure the output directory exists
    if not os.path.exists(output_dir):
        os.makedirs(output_dir)
    
    ydl_opts = {
        'format': '(bestvideo[height<=1080][ext=mp4]/bestvideo)+bestaudio/best',
        'merge_output_format': 'mp4',
        'write_auto_sub': True,
        'writesubtitles': True,
        'subtitleslangs': ['en'],
        'subtitlesformat': 'vtt',
        'embedsubtitles': True,
        'outtmpl': os.path.join(output_dir, '%(title)s.%(ext)s'),
        'postprocessors': [{
            'key': 'FFmpegVideoConvertor',
            'preferedformat': 'mp4',
        }],
    }

    with YoutubeDL(ydl_opts) as ydl:
        ydl.download([url])

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python download_video.py ")
        sys.exit(1)

    youtube_url = sys.argv[1]
    download_video(youtube_url)


  


  This script successfully downloads the video in 1080p quality or the best available quality and merges the audio and video files as intended. However, it does not download the subtitles as intended.

  


  I have ffmpeg installed for merging the video and audio files. How can I modify this script to ensure that English subtitles are downloaded and embedded in the video file ?

  


• hwcontext_vulkan : rewrite upload/download

  18 juillet 2024, par Lynne

  hwcontext_vulkan : rewrite upload/download
  This commit was long overdue. The old transfer dubiously tried to
  
  merge as much code as possible, and had very little in the way
  
  of optimizations, apart from basic host-mapping.
  The new code uses buffer pools for any temporary bufflers, and
  
  handles falling back to buffer-based uploads if host-mapping fails.
  Roundtrip performance difference :
  
  ffmpeg -init_hw_device "vulkan=vk:0,debug=0,disable_multiplane=1" -f lavfi \
  
   i color=red:s=3840x2160 -vf hwupload,hwdownload,format=yuv420p -f null -
  7900XTX :
  
  Before : 224fps
  
  After : 502fps
  Ada, with proprietary drivers :
  
  Before : 29fps
  
  After : 54fps
  Alder Lake :
  
  Before : 85fps
  
  After : 108fps
  With the host-mapping codepath disabled :
  
  Before : 32fps
  
  After : 51fps
  

  • [DH] libavutil/hwcontext_vulkan.c
  • [DH] libavutil/vulkan.c