RLovelett

Force RGB pixel format over YCbCr

There are some monitors, in my case Dell U2413, that report having YCbCr support when plugged in over HDMI. My AMD Radeon RX 570 Series video card sees this YCbCr pixel format and then prefers that over the RGB pixel format. The result is that fonts, graphics and other visuals are pixelated and not smooth in Ubuntu.

This actually is not just a Linux problem. A similar problem exists on macOS with the same monitor hooked up over HDMI. In fact an article by John Ruble on the Atomic Object blog called Fixing the External Monitor Color Problem with My 2018 MacBook Pro attempts to fix the exact same thing.

Solution

All of the articles I could find exploring this topic advocate patching the EDID for the monitor. Unfortunately the macOS solution would not work here. Luckily I found a Reddit post that covered how to get it working.

RLovelett

zfs list -r -H -t snapshot -o name stream/lxc/stash | xargs -n1 zfs destroy

RLovelett

libvirtd Fedora 28

System Packages

$ dnf install -y \
    libvirt \
    libvirt-python \
    libguestfs-tools \
 qemu-kvm \

RLovelett

Setting up ftrace

$ sudo su - root
$ cd /sys/kernel/debug/tracing
$ cat available_tracers
hwlat blk mmiotrace function_graph wakeup_dl wakeup_rt wakeup function nop
$ cat available_filter_functions | grep ftdi_sio | cut -d' ' -f1 | tr '\n' ' ' > set_ftrace_filter
$ cat set_ftrace_filter
get_serial_info [ftdi_sio]

RLovelett

import Glibc

var action = posix_spawn_file_actions_t()
posix_spawn_file_actions_init(&action);
defer { posix_spawn_file_actions_destroy(&action) }
posix_spawn_file_actions_addopen(&action, 1, "/tmp/foo-log", (O_WRONLY | O_CREAT | O_TRUNC), 0644)
posix_spawn_file_actions_adddup2(&action, 1, 2)

let args = [
  "ffmpeg",

RLovelett

#!/usr/bin/env bash

# Good:  2bd25930
# Bad:   71090e7a

set -ex

BINUTILS_DIR=$HOME/packages/trunk
SWIFT_DIR=$HOME/swift

RLovelett

Note: This is an older post that I did back when I thought I might have time to be a blogger. Oh I was oh so wrong. However, it has proven useful for some folks on stackoverflow. Thus I'm keeping it alive here on Gist.

One of my past projects dealt heavily with an open source Apple technology called HTTP Live Streaming. It’s an HTTP based streaming protocol that at its most fundamental level provides a way to stream video and audio from just about any server with nothing but a few free software tools provided by Apple**. However, it has a few additional features that I think make it a really exciting tool. Yet, I haven’t seen HTTP Live Streaming used very much. This is probably mainly due to the combination of a lack of good/clear documentation, and Apple’s Live Streaming Developer Tools being command line based also make the barrier to entry higher than many developers want to deal with.

The hope is to share my understanding of how to use this technology to:

RLovelett

# See smb.conf.example for a more detailed config file or
# read the smb.conf manpage.
# Run 'testparm' to verify the config is correct after
# you modified it.

[global]
    workgroup = SAMBA
    security = user
    passdb backend = tdbsam
    load printers = no

RLovelett

# https://github.com/macports/macports-ports/blob/master/devel/cctools/Portfile

curl -o cctools-921.tar.gz https://opensource.apple.com/tarballs/cctools/cctools-921.tar.gz
curl -o llvm-8.0.1.src.tar.xz https://github.com/llvm/llvm-project/releases/download/llvmorg-8.0.1/llvm-8.0.1.src.tar.xz
curl -o ld64-409.12.tar.gz https://opensource.apple.com/tarballs/ld64/ld64-409.12.tar.gz

tar xvf cctools-921.tar.gz
tar xvf llvm-8.0.1.src.tar.xz
tar xvf ld64-409.12.tar.gz

RLovelett

cmake_minimum_required(VERSION 3.12.4)

find_package(Python2 COMPONENTS Interpreter)
find_package(Python3 COMPONENTS Interpreter)

if (NOT Python2_Interpreter_FOUND AND NOT Python3_Interpreter_FOUND)
  message(FATAL_ERROR "Could NOT find Python2 or Python3")
endif()

# https://github.com/Kitware/CMake/blob/cfc92b483fbd3695d4a67843977e709ba4d7ea47/Modules/FindPython/Support.cmake#L2433-L2439