Recherche avancée

Sur d’autres sites (6721)

• What is the equivalent of ImageMagick's -liquid-rescale in FFMPEG

  22 février 2024, par Mouaad Abdelghafour AITALI

  I'm interested in the Content-Aware Scale effect. So far, the only way to achieve it is by using ImageMagick (distortion algorithm)

  


  

  


  cmd = f"magick {curFramePath}\

-liquid-rescale {100-DISTORT_PERCENTAGE}x{100-DISTORT_PERCENTAGE}%!\

-resize {videoSize[0]}x{videoSize[1]}\! {resFramePath}"


  


  I would love to achieve comparable results using only FFMPEG.

  


  Thank you for your help

  


• avfilter/x86/f_ebur128 : replace AVX2 instruction with AVX equivalent

  22 juin, par James Almer

  avfilter/x86/f_ebur128 : replace AVX2 instruction with AVX equivalent
  Using vpbroadcastq in an AVX function will result in SIGILL errors on pre
  
  Haswell/Zen processors.
  Signed-off-by : James Almer <jamrial@gmail.com>
  

  • [DH] libavfilter/x86/f_ebur128.asm

• Decoding the h.264 stream from a serial port

  18 mars, par Peter

  I would like to know if there is a reliable way to decode an H.264 NAL stream coming through a serial port using software.

  


  So far, I have managed to decode a single frame using a python script. In this script, I first write the incoming data to a file, and when the end-of-frame marker 00_00_00_01 appears, I display the frame using ffplay.

  


  import serial
import subprocess
import os
import time

ser = serial.Serial('COM3', 115200, timeout=1)
output_file = "output.264"

# Variable to store the ffplay process
ffplay_process = None

# Open the file for writing in binary mode
with open(output_file, "wb") as file:

    print("Writing bytes to output.264. Waiting for the end-of-frame marker 0x00000001.")

    buffer = bytearray()
    marker = b'\x00\x00\x00\x01'

    try:
        while True:
            if ser.in_waiting:  # If there is data in the buffer
                data = ser.read(ser.in_waiting)  # Read all available bytes
                buffer.extend(data)

                # Check if the end-of-frame marker is in the buffer
                while marker in buffer:
                    index = buffer.index(marker) + len(marker)  # Position after the marker
                    frame = buffer[:index]  # Extract the frame
                    buffer = buffer[index:]  # Keep the remaining data

                    print(f"Frame recorded: {len(frame)} bytes")
                    file.write(frame)  # Write the frame to the file
                    file.flush()  # Force writing to disk

                    # Close the ffplay window if it is already open
                    if ffplay_process and ffplay_process.poll() is None:
                        ffplay_process.terminate()
                        ffplay_process.wait()  # Wait for the process to terminate

                    # Play the recorded frame, reopening the window
                    ffplay_process = subprocess.Popen(["ffplay", "-f", "h264", "-i", output_file])

    except KeyboardInterrupt:
        print("\nRecording stopped.")
    finally:
        # Close the serial port and the ffplay process
        ser.close()


  


  However, each time a new end-of-frame marker is detected, the ffplay window closes and reopens to show the next frame. It will flicker when transferring the video. Is there a way to display the frames in the same window for seamless playback when streaming video ?

  


  Or is there a better approach or software that is more suited for this task ? I do not know where to start, so I will be glad for any hints.