sfahadshahzad

What is it for

FFMPEG based delay loop running in RAM for Blackmagic Decklink video cards. It's useful if you need a "profanity protection" buffer, but could also be used as a poormans instant replay.

How does it work

The idea behind this is to use exploit ffmpeg's concat filter as an intermediate buffer. The length of the delay line is set by the -t parameter before anullsrc in the example below ((or d after smptehdbars).

In my case I wanted PAL interlaced input and output. If you want to use different framerate change the format using the aproppriate -format_code parameter.

FFmpeg streaming

These are some ffmpeg command lines used when developing VHS dubbing controller.

HLS Stream (on Linux)

#!/bin/bash

# Stream a PAL 50i capture, cropped and de-interlaced using ffmpeg

FFmpeg build for NVIDIA & Intel hardware on Ubuntu 18.04LTS+:

Build platform: Ubuntu 18.04LTS

Goals: Generate an FFmpeg build that can utilize NVENC hardware acceleration on NVIDIA-based systems on Ubuntu 18.04LTS+.

First steps:

Purge all NVIDIA drivers first:

Gstreamer Pipeline Samples
Media File

Gstreamer Pipeline Samples

Table of Contents:

Gstreamer Pipeline Samples
- Tips for Debug
- Video
  - display test video
  - record to file
record and display at the same time(queue)

	from kivy.app import App
	from kivy.uix.widget import Widget
	from kivy.uix.boxlayout import BoxLayout
	from kivy.uix.image import Image
	from kivy.clock import Clock
	from kivy.graphics.texture import Texture

	import cv2
	import numpy as np

	# To extract the sound from a video and save it as MP3:
	ffmpeg -i <video.mp4> -vn <sound>.mp3

	# To convert frames from a video or GIF into individual numbered images:
	ffmpeg -i <video.mpg\|video.gif> <frame_%d.png>

	# To combine numbered images (frame_1.jpg, frame_2.jpg, etc) into a video or GIF:
	ffmpeg -i <frame_%d.jpg> -f image2 <video.mpg\|video.gif>

	# To quickly extract a single frame from a video at time mm:ss and save it as a 128x128 resolution image:

	# To extract the sound from a video and save it as MP3:
	ffmpeg -i <video.mp4> -vn <sound>.mp3

	# To convert frames from a video or GIF into individual numbered images:
	ffmpeg -i <video.mpg\|video.gif> <frame_%d.png>

	# To combine numbered images (frame_1.jpg, frame_2.jpg, etc) into a video or GIF:
	ffmpeg -i <frame_%d.jpg> -f image2 <video.mpg\|video.gif>

	# To quickly extract a single frame from a video at time mm:ss and save it as a 128x128 resolution image:

	@echo off

	:: Configuration Variables
	set "ifName=Ethernet 2"
	set "ipAddress=10.88.167.35"
	set "subnetMask=255.255.255.240"
	set "vlanID=702"

	:: set "defaultGateway=x.x.x.x"
	:: set "primaryDNS=x.x.x.x"

	#!/bin/bash


	ffmpeg -re -analyzeduration 100M -probesize 100M -stream_loop -1 -i <input_file.ts> \
	-vf setdar=16/9 -f decklink -pix_fmt uyvy422 -format_code pal "DeckLink Mini Monitor"