Discover gists

FFmpeg cheat sheet

A list of useful commands for the FFmpeg command line tool.

Download FFmpeg: https://www.ffmpeg.org/download.html

Full documentation: https://www.ffmpeg.org/ffmpeg.html

Basic conversion

dataset	meta data	contents	with audio
200DrumMachines		7371 one-shots	yes
AAM	onsets, pitches, instruments, melody instrument, keys, chords, tempo, beats	3000 (artificial) tracks	yes
ACM_MIRUM	tempo	1410 excerpts (60s)	yes
ACPAS	aligned audio and scores	2189 performances of 497 scores	downloadable
AcousticBrainz-Genre	15-31 genres with 265-745 subgenres	audio features for over 2000000 songs	no

Opening and closing an SSH tunnel in a shell script the smart way

I recently had the following problem:

From an unattended shell script (called by Jenkins), run a command-line tool that accesses the MySQL database on another host.
That tool doesn't know that the database is on another host, plus the MySQL port on that host is firewalled and not accessible from other machines.

We didn't want to open the MySQL port to the network, but it's possible to SSH from the Jenkins machine to the MySQL machine. So, basically you would do something like

ssh -L 3306:localhost:3306 remotehost

DynamoDB Query Evaluation Order Differs from SQL

Summary:

When using LIMIT in DynamoDB queries, the order of evaluation can differ from SQL queries, potentially leading to unexpected results depending on the search criteria used.

SQL Query Evaluation Order:

SQL queries follow a specific order of evaluation:

FROM -&gt; ON -&gt; JOIN -&gt; WHERE -&gt; GROUP BY -&gt; HAVING -&gt; SELECT -&gt; DISTINCT -&gt; ORDER BY -&gt; LIMIT

Удалить/очистить все данные Докера (контейнеры, образы, тома и сети)

Одной строкой

docker stop $(docker ps -qa) && docker rm $(docker ps -qa) && docker rmi -f $(docker images -qa) && docker volume rm $(docker volume ls -q) && docker network rm $(docker network ls -q)

Описание команд

Instructions for a mac on how to play with pyenv and poetry

Why both? Pyenv to manage multiple python versions. You can make virtualenvs with pyenv of course, but using poetry will simplify that process

# Install pyenv.
brew install pyenv

# Add pyenv initializer to shell startup script.
echo -e '\nif command -v pyenv 1>/dev/null 2>&1; then

The repository for the assignment is public and Github does not allow the creation of private forks for public repositories.

The correct way of creating a private frok by duplicating the repo is documented here.

For this assignment the commands are:

Create a bare clone of the repository. (This is temporary and will be removed so just do it wherever.)

git clone --bare git@github.com:usi-systems/easytrace.git

	# Patch 1 of 4. Create node_modules/mdast-util-to-markdown/lib/util/check-underline.js

	/**
	* @typedef {import('../types.js').Options} Options
	* @typedef {import('../types.js').State} State
	*/

	/**
	* @param {State} state
	* @returns {Exclude<Options['underline'], null \| undefined>}

	# start GremlinServer
	# bin/gremlin-server.sh -i org.apache.tinkerpop gremlin-python 3.2.2-SNAPSHOT
	# bin/gremlin-server.sh conf/gremlin-server-modern-py.yaml

	from gremlin_python.process.graph_traversal import GraphTraversal
	from gremlin_python.process.graph_traversal import GraphTraversalSource
	from gremlin_python.process.graph_traversal import __
	from gremlin_python.process.traversal import Operator

	from gremlin_python.structure.io.graphson import GraphSONReader

	Extend lvm partition in ubuntu server.
	my lv group name is ubuntu-vg
	my lv name is ubuntu-lv
	my lv path is /


	Verify Free Space: First, ensure that you have available free space on your physical volume (disk) or a new disk that you can add to your volume group. You can check the available space by running the command:
	``` sudo vgdisplay ubuntu-vg ```

	Create a New Partition: If you have added a new disk, you need to create a new partition on it. Use the appropriate partitioning tool (e.g., fdisk, parted, etc.) to create a new partition. Make sure the partition type is set to "8e" (Linux LVM).