ODR-PadEnc
ODR-PadEnc is an encoder for Programme Associated Data (PAD) and includes support for:
- MOT Slideshow (including catSLS), according to ETSI EN 301 234 and TS 101 499
- DLS (including DL Plus), according to ETSI EN 300 401 and TS 102 980
To encode DLS and Slideshow data, the odr-padenc tool reads images
from a folder and DLS text from a file, and generates the PAD data
for the encoder.
For detailed usage, see the usage screen of the tool with the -h option.
More information is available on the Opendigitalradio wiki
Installation
You have 3 ways to install odr-padenc on your host:
Using your linux distribution packaging system
odr-padenc is available on the official repositories of several debian-based distributions, such as Debian
(from Debian 12), Ubuntu (from 24.10), Opensuse and Arch.
If you are using Debian 12 (Bookworm), you will need to add the backports repository
Using installation scripts
If your linux distribution is debian-based, you can install odr-padenc as well as the other main components of the mmbTools set with the Opendigitalradio dab-scripts
Compiling manually
Unlike the 2 previous options, this one allows you to compile odr-padenc with the features you really need.
Requirements
For Debian Bullseye-based OS, run the following commands:
# Required packages
## C++11 compiler
sudo apt-get install --yes build-essential automake libtool
# optional package
## ImageMagick MagickWand (optional, for MOT Slideshow), version 6 (legacy) or 7
sudo apt-get install libmagickwand-dev
Compilation
- Clone this repository: ``` # stable version: git clone https://github.com/Opendigitalradio/ODR-PadEnc.git
# or development version (at your own risk):
git clone https://github.com/Opendigitalradio/ODR-PadEnc.git -b next
1. Configure the project
cd ODR-PadEnc
./bootstrap
./configure
1. Compile and install:
make
sudo make install
```
ImageMagick and Debian Jessie/Ubuntu 16.04
Please note that Debian Jessie and Ubuntu 16.04 shipped a version of ImageMagick that was affected by two memory leaks (see #2, and also Ubuntu's #1671630 and #1680543). Hence ODR-PadEnc increasingly consumed memory until it crashed.
This has been fixed with the following package versions: - Debian Jessie: 8:6.8.9.9-5+deb8u9 - Ubuntu 16.04: 8:6.8.9.9-7ubuntu5.7
Usage of MOT Slideshow and DLS
Basic example
odr-padenc reads images from the specified folder, and generates the PAD
data for the encoder. This is communicated through a socket to the encoder. It
also reads DLS from a file, and includes this information in the PAD.
PAD length is specified in the audio encoder and must not be set on the odr-padenc command line.
Basic example with both DLS taken from the file dls.txt and MOT Slideshow carousel with slides from the slides folder. This assumes the common identifier between audio encoder and ODR-PadEnc is defined in the IDENTIFIER environment variable.
odr-padenc -o $IDENTIFIER -t dls.txt -d ./slides
If you generate slides on-the-fly (e.g. content-related slides with album covers), set the --erase flag to ensure a
slide is only transmitted once, and set --sleep=0 to start slide transmission as soon as the file is created.
If ImageMagick is available
It can read all file formats supported by ImageMagick, and by default resizes them to 320x240 pixels, and compresses them as JPEG. If the input file is already a JPEG file of the correct size, and smaller than 50kB, it is sent without further compression. If the input file is a PNG that satisfies the same criteria, it is transmitted as PNG without any recompression.
RAW Format
If ImageMagick is not compiled in, or when enabled with the -R option, the images
are not modified, and are transmitted as-is. Use this if you can guarantee that
the generated files are smaller than 50kB and not larger than 320x240 pixels.
Files whose name end in _PadEncRawMode.png or _PadEncRawMode.jpg will always
be transmitted in RAW mode.
It may be useful to apply optipng to any PNG file prior to transmission.
Supported Encoders
odr-audioenc and odr-sourcecompanion can insert the PAD data from odr-padenc into the bitstream.
This is an ongoing development. Only some PAD lengths are supported, please see odr-padenc's help.
ODR-PadEnc v2 is compatible with ODR-AudioEnc v2 and ODR-SourceCompanion v0.x, and uses a fifo to communicate between the tools.
ODR-PadEnc v3 replaced the fifo with a socket and is compatible with ODR-AudioEnc v3 and ODR-SourceCompanion v1.
Character Sets
When odr-padenc is launched with the default character set options, it assumes
that the DLS text in the file is encoded in UTF-8, and will convert it according to
the DAB standard to the Complete EBU Latin based repertoire character set encoding.
If you set the character set encoding to any other setting (except
Complete EBU Latin based repertoire which needs no conversion),
odr-padenc will abort, as it does not support any other conversion than from
UTF-8 to Complete EBU Latin based repertoire.
You can however use the -C option to transmit the untouched DLS text. In this
case, it is your responsibility to ensure the encoding is valid. For instance,
if your data is already encoded in Complete EBU Latin based repertoire, you
must specify both --charset=0 and --raw-dls.
Known Limitations
Some receivers are unable to decode slides larger than some size, even within the allowed size limit given in the specification.
Thanks
This encoder was initially called mot-encoder and has been contributed by
CSP.