Creating a bootable usb key from a cd image

if you want to create a bootable usb key from a cd isoimage, first check that your iso is ready for that

$ fdisk -l Porteus-MATE-v3.1-i486.iso

Disque Porteus-MATE-v3.1-i486.iso : 250 Mo, 250468352 octets
255 têtes, 63 secteurs/piste, 30 cylindres, total 489196 secteurs
Unités = secteurs de 1 * 512 = 512 octets
Taille de secteur (logique / physique) : 512 octets / 512 octets
taille d'E/S (minimale / optimale) : 512 octets / 512 octets
Identifiant de disque : 0x00000000

Le disque Porteus-MATE-v3.1-i486.iso ne contient pas une table de partitions valable

The last line indicates that the iso doesn't contain a partition table and that may prohibit your key from being bootable on some systems.

To correct that, first install the isolinux package on your system:
$ apt-get install syslinux


then add the partition table
$ isohybrid Porteus-MATE-v3.1-i486.iso

Then check


$ fdisk -l Porteus-MATE-v3.1-i486.iso

Disque Porteus-MATE-v3.1-i486.iso : 250 Mo, 250609664 octets
64 têtes, 32 secteurs/piste, 239 cylindres, total 489472 secteurs
Unités = secteurs de 1 * 512 = 512 octets
Taille de secteur (logique / physique) : 512 octets / 512 octets
taille d'E/S (minimale / optimale) : 512 octets / 512 octets
Identifiant de disque : 0x515facbe

             Périphérique Amorçage  Début         Fin      Blocs    Id. Système
Porteus-MATE-v3.1-i486.iso1   *           0      489471      244736   17  HPFS/NTFS masquée

To copy the image
$ dd if=Porteus-MATE-v3.1-i486.iso of=/dev/sdX

 

Streaming SONY CX900 video via ustream

Tech requirements

-Blackmagick Decklink Minirecorder or other acquisition card + software
-FFMPEG compiled with blackmagick support :

./configure --enable-decklink --enable-shared --extra-cflags="-I/usr/include/blackmagic" –enable-libx264 --enable-libvpx --enable-libvorbis --enable-gpl

put your camera on and connect it to the decklink card through the hdmi cable
verify your settings are ok with media express.
The you can launch the FFmpeg command

ffmpeg -thread_queue_size 4096 -f decklink -i 'DeckLink Mini Recorder@11' -vf scale=1280:720 -r 10 -f flv -an -vcodec libx264 -threads 4 -preset fast -b:v 700k -pix_fmt yuv420p -y rtmp://<your url...>/<Your key...>

your url and key are given in the brodcast settings of the your ustream dashboard

 
Here I use 10 frame/second to broadcast good image quality at a quite low bitrate. You can adjust your settings size bitrate etc... according to your specific needs and bandwidth
https://support.ustream.tv/hc/en-us/articles/207852117-Internet-connection-and-recommended-encoding-settings

To view the stream a link is provided by ustream when you created your tv channel.
You can watch whatever I try to stream here http://ustre.am/1xdhZ Septembre 10 between 20:00 and 23:00 Paris time.