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• How to transcode a video using python and ffmpeg library (no commandline call)

  25 mars 2014, par mojovski

  I would like to transcode a video using python and ffmpeg. But I dont want to use a command line call like
  call(ffmpeg -i ....")

  I will need to deploy the resulting application using py2exe, thus cannot use call method.

  Thanks in advance !

• Trim / Cut video on Android using FFMpeg's Copy

  6 août 2012, par Kevin P

  We're trying to replicate the functionality of this command line ffmpeg directive using the FFMpeg c api through JNI calls on Android.

  ffmpeg -ss 2 -t 120 -vcodec copy -acodec copy -i input.file output.file

  Basically, given a start and end time, we wish to copy (not re-encode) a small(er) segment of video from the larger (input) video source.

  We've been using the wonderful JavaCv wrapper to openCv and FFMpeg, but we just cannot figure out how to do this simple bit of work. We've been scouring the ffmpeg.c and related sources and while I now understand that it switches to stream_copy and remuxing rather than re-encoding when the codec is specified as copy I cannot for the life of me identify what series of method calls to make to replicate this through the C api. Does anyone have an example JNI file for doing this ? Or are there rockstar C types that can explain how I get from that command line to api calls ? We've spent the better part of two weeks working on this (we're not native C guys) and we're at the point where we just need to ship some code. Any example code, especially JNI code or method call maps etc. would be greatly appreciated !

• Python opencv subprocess write return broken pipe

  16 septembre 2021, par Vamsi

  I want to read an rtsp video source, add overlay text and push it to the RTMP endpoint.I am using Videocapture to read the video source and python subprocess to write the frames back to RTMP endpoint. I referred this FFmpeg stream video to rtmp from frames OpenCV python

  


  import sys
import subprocess

import cv2
import ffmpeg
rtmp_url = "rtmp://127.0.0.1:1935/live/test"

path = 0
cap = cv2.VideoCapture("rtsp://10.0.1.7/media.sdp")

# gather video info to ffmpeg
fps = int(cap.get(cv2.CAP_PROP_FPS))
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))



command = ['ffmpeg', '-i', '-', "-c", "copy", '-f', 'flv', rtmp_url]
p = subprocess.Popen(command, stdin=subprocess.PIPE, stderr=subprocess.PIPE, stdout=subprocess.PIPE)

font = cv2.FONT_HERSHEY_SIMPLEX
while cap.isOpened():

    ret, frame = cap.read()
    cv2.putText(frame, 'TEXT ON VIDEO', (50, 50), font, 1, (0, 255, 255), 2, cv2.LINE_4)
    cv2.imshow('video', frame)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

    if not ret:
        print("frame read failed")
        break

    try:
        p.stdin.write(frame.tobytes())
    except Exception as e:
        print (e)


cap.release()
p.stdin.close()
p.stderr.close()
p.wait()


  


  The python script returns "[Errno 32] Broken pipe". Running the ffmpeg command in the terminal works fine.

  


  


  ffmpeg -i rtsp ://10.0.1.7/media.sdp -c copy -f flv
rtmp ://127.0.0.1:1935/live/test

  


  


  The above command works fine, and I can push the input stream to RTMP endpoint. But I can't write processed frame to subprocess which has ffmpeg running.

  


  Please let me know, if I miss anything.