CODEWITHSUNDEEP
pythonopencvvlc
Seb A
Seb A

Reputation: 21

How to get the frame from the vlc media player

I'm currently using vlc library for python (python-vlc) to get the video stream from a sdp stream describe with a sdp file. I'm currenctly using this code : 

import vlc
import time 

instance = vlc.Instance()
player = instance.media_player_new()
media = instance.media_new("./bebop.sdp")
player.set_media(media)

player.play()
time.sleep(10)

Which works well to display the video. But I don't want to just display it, I want to use each frame from the video to make some image processing on it and then to display the modified frames.

I've read almost all the documentation and diverse post on forums but I can't find a way to do this.

I use vlc to get the video stream because open cv can't open it because of some ffmpeg error.

Upvotes: 2

Views: 8142

Answers (3)

mfkl
mfkl

Reputation: 2159

You need to use a bunch of libvlc calls, not sure what those are with your python wrapper but they should be exposed on the mediaplayer object.

https://www.videolan.org/developers/vlc/doc/doxygen/html/group__libvlc__media__player.html#gae46128c21d0d0151aca3ba017d1d6b35

https://www.videolan.org/developers/vlc/doc/doxygen/html/group__libvlc__media__player.html#ga2189c9deefc2154ddc5d5f1871b0a106

https://www.videolan.org/developers/vlc/doc/doxygen/html/group__libvlc__media__player.html#ga193de3e82f6de3f9d8f5ccd8b5f2aa98

https://www.videolan.org/developers/vlc/doc/doxygen/html/group__libvlc__media__player.html#ga024c0f0bba9d3b32a881c40f3cb479bb

You need to setup and use these callbacks. C# example using those APIs: https://github.com/ZeBobo5/Vlc.DotNet/blob/develop/src/Vlc.DotNet.Wpf/VlcVideoSourceProvider.cs

Upvotes: 0

Rolf of Saxony
Rolf of Saxony

Reputation: 22443

Get the frames per second from the video or default to 25 as a reasonable guess, then step through the paused video, using the frames per second as your jump forward each time.

import vlc
import time

instance = vlc.Instance('--no-xlib --quiet')
player = instance.media_player_new()
media = instance.media_new("./bebop.sdp"")
player.set_media(media)
player.play()
mfps = int(1000 / (player.get_fps() or 25))
player.set_time(30000) # start at 30 seconds
player.pause()
t = player.get_time()
for iter in range(30):
    t += mfps
    player.set_time(t)
    if player.get_state() == 3:
        player.pause()
    time.sleep(0.5)

Here, I start at the 30 second mark and then advance just 30 times.
You will probably want to keep advancing until player.get_state() == 6 indicating that the video has finished. [state 3 = playing]

Upvotes: 1

Degang Guo
Degang Guo

Reputation: 505

# -*- coding: utf-8 -*-

import vlc
import time 

def mspf(mp):
    """Milliseconds per frame"""
    return int(1000 // (mp.get_fps() or 25))


if __name__ == "__main__":
    instance = vlc.Instance()
    player = instance.media_player_new()
    media = instance.media_new("1.m4v")
    player.set_media(media)

    player.play()

    """Play 800th frames"""
    new_time = 800 * mspf(player)
    player.set_time(new_time)

    time.sleep(10)

Upvotes: 0

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