revolunet

Live Transcoding

This is a collection of working commandline examples to show how one could use FFMpeg and VLC for live transcoding of video streams. All examples have been tested on OSX 10.7.5 with FFMPeg 1.1.3 and VLC 2.0.5 in early 2013.

Documentation links

• FFMpeg, Muxers, Encoders, Protocols
• FFMPEG multiple outputs
• VLC Docu, Advanced Use

shahnhogan

curl -O https://download.redisinsight.redis.com/latest/RedisInsight-v2-win-installer.exe

lynt-smitka

<IfModule mod_rewrite.c>
  RewriteEngine On
  RewriteCond %{QUERY_STRING} ^(.*?)(&?fbclid=[a-zA-Z0-9_-]+)$
  RewriteRule ^(.*)$ /$1?%1 [L,NE,R=301]
</IfModule>

Brainiarc7

Low-Latency Live Streaming for your Desktop using ffmpeg and netcat:

Preamble:

In this post I will explore how to stream a video and audio capture from one computer to another using ffmpeg and netcat, with a latency below 100ms, which is good enough for presentations and general purpose remote display tasks on a local network.

The problem:

Streaming low-latency live content is quite hard, because most software-based video codecs are designed to achieve the best compression and not best latency. This makes sense, because most movies are encoded once and decoded often, so it is a good trade-off to use more time for the encoding than the decoding.

cbarraco

# If the server has ffmpeg:
## For the server:
ffmpeg -f fbdev -i /dev/fb0 -f avi pipe:1 | nc -l -p 1234
## For the viewer:
nc 127.0.0.1 1234 | ffplay -i pipe:0

# If the server doesn't have ffmpeg:
## For the server:
sudo cat /dev/fb0 | nc -l -p 1234
## For the viewer (replace 1920x1080 with the server's resolution):

kurlov

ffmpeg -i in.mkv -f srt -i in.srt -map 0:0 -map 0:1 -map 1:0 -c:v copy -c:a copy -c:s srt out.mkv

dlqqq

Random "Freezing" with AMD Ryzen CPUs

It seems that numerous GNU/Linux users (including myself) have been having issues with the system randomly "freezing" during light usage. From journalctl output and anecdotal accounts, it is speculated that the AMD Ryzen CPUs do not support other C-states for power management very well (at least on GNU/Linux distributions), and the freezing may be resolved by limiting the C-state of the CPU.

Possible Solution

Limiting the C-state of the CPU can be done through the addition of the following kernel boot parameter.

processor.max_cstate=1

giu1io

#!/bin/bash

WPA_SUPPLICANT_CONF="/etc/wpa_supplicant/wpa_supplicant.conf"

# this funcion is called once the connection is established,
# in this case a boot sound will be played to notify the user that everything is ready.
function connected {
	aplay /root/Windows3.1.wav 2>&1 >/dev/null &
}

harv

#! /bin/sh

# update glibc to 2.17 for CentOS 6

wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-2.17-55.el6.x86_64.rpm
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-common-2.17-55.el6.x86_64.rpm
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-devel-2.17-55.el6.x86_64.rpm
wget http://copr-be.cloud.fedoraproject.org/results/mosquito/myrepo-el6/epel-6-x86_64/glibc-2.17-55.fc20/glibc-headers-2.17-55.el6.x86_64.rpm

sudo rpm -Uvh glibc-2.17-55.el6.x86_64.rpm \

lynt-smitka

http {

  ...
  
  # redirect map in http block - remove fbclid argument from the end
  map $request_uri $redirect_fbclid {
    "~^(.*?)([?&]fbclid=[a-zA-Z0-9_-]+)$"  $1;
  }
  
  ...