How to Check a Video’s Bitrate In VLC

Link

SCP transfer to/from Raspberry (using passwordless SSH)

I was used to use Filezilla for transferring file between my Ubuntu laptop and Raspberry Pi Zero, but every time it took a while even if it was a matter of transferring small files. 

The problem was the way of checking password (probably “double checking” password). 

So I decided to leave Filezilla for using the SCP command with no password.

I configured a passwordless SCP following the instructions available here. 

# cd $HOME/.ssh
# mv id_rsa.pub id_rsa.pub-RPiZero

When I had to copy and paste the public key on my Raspberry Pi Zero board, I had to use the next command: 

cat ~/.ssh/id_rsa.pub-RPiZero | ssh pi@<IP-ADDRESS> 'mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys'

as reported here. 

Following the instructions reported in the links available above I was finally able to share small files between my computer and my Raspberry Pi Zero board in a short time, instead of wasting time with Filezilla. 

FFMPEG - Audio Volume Manipulation

I recycled an old iPod Nano 6th Generation for listening to podcasts while I’m travelling. Unfortunately the audio quality is not so good: even if you pressed the Volume Up button till the highest volume available, the volume is not high enough anyway. 

So the solution is to set an higher volume on every single audio file. For doing that, in the past I used Audacity, but for setting an higher volume on many files at the same time that’s not a really easy solution. There are some solution available on the web about using Audacity for manipulating audio volume on many files at the same time, like using macros. I found using FFMPEG as an easier solution compared to Audacity. 

Here you can find some samples about how to change the audio volume using FFMPEG. For increasing the volume on many audio files (mp3) at once I wrote the next .bat file (testing some samples available on the web): 

@echo off
cls
REM Creo la cartella contenente i nuovi file audio
md newfiles
REM Comincio la conversione
for %%a in (“*.mp3”) do ffmpeg.exe -i “%%a” -filter:a “volume=10dB” “newfiles\%%a” -hide_banner
pause