Author Archives: h0nk3ym0nk3y

How to expand a partition on the fly

http://commons.wikimedia.org/wiki/File:Crystal_128_harddrive.pngI’ve just had some troubles with my Odroid XU4 complaining that there was no more space left on the micro SD card. It’s a 16 GB card so I was wondering what caused this. As it turned out I simply forgot to expand the root partition to the size of the SD card, so I thought I’ll write a post about how to easily and safely expand a mounted linux partition on the fly without having to reboot the system.
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How to silence an Odroid XU4

Odroid XU4 fan modI love these little single-board computers. They’re small, cheap, energy efficient, powerful, extremely versatile, have several digital and analog I/Os and… generate the fan noise from hell! In this tutorial I will demonstrate how I modded my Odroid XU4 to make it (almost) unhearable.

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How to shrink PDFs

pdfcomressSometimes a PDF document you’ve created is several megabytes in size due to high resolution images. This may cause problems when you want to send this PDF via email if the attachement’s size is limited by your email provider. There is a way you can reduce the file size of an existing PDF without having to render it again with low resolution images.
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How to create a video DVD with command line tools

DVDsMaybe you know this scenario: You’ve been invited to a family get-together and you take some videos of the most memorable events. Afterwards a family member comes to you and says: “I’ve seen you recording this and that. Could you give it to me on DVD?”. As a matter of fact, you can easily create a video DVD of any video you have recorded with just a view command lines.
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How to use a remote firewire port and transcode DV video locally with ffmpeg

Vhs_cassette_bottomI recently moved into another appartment and found some old VHS tapes I recorded years ago. As luck would have it, I got my hands on a VCR and a MiniDV camcorder with builtin ADC, so I can get analog video signals into the MiniDV camcorder. So all I needed was a computer with firewire or IEEE1394 port. The only computer I have that still has a firewire port is my server, so I hooked the VCR to the MiniDV and the MiniDV to my server.
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How to trim disk images to partition size

I’ve recently been playing with my Raspberry Pi and Arch Linux when I encountered the following problem:

I’ve downloaded the Arch Linux image from the Raspberry Pi download page and used dd to copy it to a 8GB SD card. Read the rest of this entry

How to make screencasts with FFmpeg

FFmpeg is able to use audio and video streams from many different sources. In order to record a screencast, you can use the x11grab input module for recording an X screen and the alsa input module for audio recording.
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How to extract video URLs from YouTube

I know there are many tools out there that allow you to download videos from YouTube, like the Video Download Helper for Firefox, even online tools that convert the audio to mp3. The reasons I’m writing this article are a) because sometimes you just need the URL, for example to watch a video with a much less ressource consuming player like VLC or ffplay, b) because sometimes you just want to listen to the audio and save up even more ressources by not decoding the video and c) because I can ūüėČ
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How to stream multiple TV channels with a single DVB-T tuner using VLC

DVB-T (Digital Video Broadcasting – Terrestrial) is the European-based digital terrestrial television broadcast transmission standard. The system transmits video, audio and data streams encoded in a MPEG transport stream which can be decoded by different types of receiver cards, boxes or USB sticks. Every broadcast channel with its video, audio and data stream is multiplexed into a MPEG program stream and one or more of these are multiplexed into a MPEG transport stream which is then transmitted on a single frequency. So basically your tuner card/box/stick is receiving multiple broadcast channels on a single frequency at once and your tuner software selects the program stream you intend to watch or record. In this article I will explain how you can demultiplex the transport stream and watch or record multiple broadcast channels at the same time with a single tuner. Read the rest of this entry

How to trim strings with bash

If you want to trim a string from or to a certain pattern, you don’t have to invoke cut, sed or awk. You can use the % operator to trim a string from the first or last occurrence of a pattern to the end or the # operator to trim from the beginning to the first or last occurrence of it.
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