jSDR, ricevitore FM e visualizzatore di spettro per chiavette RTL-SDR (sotto Linux)

C'è un aggiornamento al software per Linux (ma ricompilabile per Windows e, forse, chissà, per Mac) jSDR, che l'olandese Jan van Katwijk ha reso disponibile qualche tempo fa per rendere possibile, tra l'altro, la decodifica di segnali in FM con front end SDR di tipo QSD, come il PMSdr. La nuova release, 3.04, si apre per la prima volta anche alle diaboliche chiavette DVB-T ultraeconomiche e a quanto mi comunica il solito amico che la sa lunga, funziona incredibilmente bene.

Il pacchetto contiene tre diversi programmi: un ricevitore HF, il ricevitore FM e un semplice visualizzatore di spettro pensato appositamente per le chiavette. Tutti i software sono testati sotto Fedora e Ubunto ma l'esecuzione dovrebbe essere possibile anche in ambienti Windows su cui girino le seguenti librerie: MINGW, Qt, Qwt and libusb-1.0 (commenti sulla possibilità di ricompilare sotto Mac sono ben accetti). La descrizione sintetica che segue aiuta a farsi un'idea delle possibilità di questo software, ma Jan ha preparato un dettagliato manualetto che si può prelevare qui. Per scaricare il tarball con il codice, invece, bisogna essere iscritti al gruppo Yahoo "soft_radio".

The package contains three programs, a simple spectrum viewer for use with the rtl2832u based dongles, a fairly complete sw receiver and an am/fm receiver running without problems under Ubuntu and Fedora, and - for the advanced user who has MINGW, Qt, Qwt and libusb-1.0 running under Windows - under Windows.

The programs contain quite some improvements since the march 5 version, the most important one being that all three programs now support the DAB sticks with the rtl2832u as sdr device. DAB sticks provide 8 bit I and Q data with a data-rate of up to 3.2 M. While the spectrum viewer provides a view on a user selectable spectrum of up to 3 MHz, and therefore needs the full bandwidth, the FM receiver supports strong filtering of the incoming data to a data rate usable for WFM. Although the I and Q sample are only 8 bits, it turns out to be quite possible to receive WFM in stereo mode with decoding of (some of the) RDS signals. Just to give an idea of what turns out to be possible with a 26Euro DAB stick, I attach a recent screenshot of the FM receiver, while listening to a (dutch) station.

So, the sw receiver supports the elektor card (2007), the pmsdr (basic version but up to 165MHz) and the DAB stick with a predefined rate of 2880000 (filtered and decimated to either 96 or 192K) The fm receiver supports the pmsdr (basic version but up to 165 MHz) and the DAB stick. Selection can be made of the decoding bandwidth and DAB sample rate. A pretty strong filter is used to select an appropriate subband of what is coming out of the DAB stick. Some of the command line parameters will set the samplerate used in decoding and the samplerate used by the DAB stick.

The spectrum viewer supports the DAB stick. A command line parameter can be used to specify the rate of the incoming samples and the width of the spectrum. The package contains some scripts that are helpful in establishing the right environment (i.e. loading the libraries and development packages needed) in a directory "installation". The package contains a general description of the programs, including sections how to set frequencies, and about some important command line parameters in the directory "docs".

ChumbyOne, evoluzione di Chumby, con FM e radio IP

Andrea B. mi fa giustamente notare che un altro dispositivo più o meno portatile (in realtà il concetto è quello della radiosveglia) che fa anche da Internet Radio è Chumby. Di questo curioso dispositivo connesso che funge in effetti anche da Ip radio ho già parlato l'anno scorso ma nel frattempo Chumby classic non è più solo, è stato affiancato da Chumby One, che ha un processore più potente e costa di meno (sarà perché ha rinunciato alla copertura in cuoio). In compenso ha una funzione importante in più, la radio FM (no, non so se con RDS). Chumby One ha anche un rappresentante italiano, Tecnologie Creative, che distribuisce anche BlobBox il set top box ibrido Web/digitale terrestre, dei miei amici di TVBlog. Chumby costa 129 euro più 10 di spedizione. La vera notizia però è che Chumby può contare su una intelligenza di bordo tutta speciale, un ambiente operativo Linux embedded su processore ARM che gli permette di funzionare anche da videoplayer (formato FLV) e di eseguire ben 1.500 applicazioni, con molte funzioni social come Twitter già integrate. I formati audio supportati sono l'MP3 e OGG, il che ne limita la capacità come radio IP, ma volete mettere la flessibilità?

PURE Sensia, la radio digitale con Linux a bordo

Frontier Silicon, fornitore di chipset per apparecchi radio digitali ibridi, annuncia di aver avviato le consegne in volume di Venice 7, nuovo modulo per radio multimodalità DAB/FM/Internet. Nel comunicato Frontier sottolinea che nazioni come il Regno Unito o la Francia hanno già fatto intravedere l'intenzione di passare dall'FM analogica al DAB in un certo numero di anni. E' puro marketing, intendiamoci, ma Frontier ha capito perfettamente che senza un forte impegno di politica industriale e normativo difficilmente la radio digitale potrà sostituire quella analogica. E del resto i prodotti di Frontier si stanno adeguando in fretta allo scenario più probabile, quello di una convivenza tra forme vecchie e nuove di radiofonia e piattaforma Internet come sistema di distribuzione di contenuti audio.
Uno dei clienti più fedeli di Frontier Silicon è PURE, che proprio in queste settimane sta uscendo con un modello di radio ibrida piuttosto interessante, alla luce delle considerazione fatte qui a proposito dell'altro ricevitore ibrido (ma non DAB) Nokia Home Music. PURE Sensia dovrebbe utilizzare una versione precedente di Venus, la 6.2, almeno a quanto spiega un interessante approfondimento di Linux Devices. Nel modulo è presente il chip Frontier Chorus 2 un processore di banda base molto avanzato compatibile con modulazioni digitali e analogiche (resta fuori la radio digitale DRM, forse a causa della diversa variante di modulazione COFDM utilizzata). Sensia è una radio per modo di dire. Il suo sistema operativo è Linux, tanto che sul suo display touchscreen da 5,7 pollici a colori verranno visualizzate anche vere e proprie applet (già pronte quelle per Twitter e Facebook, non a caso Sensia viene presentata come la radio per la Facebook generation). Il nuovo dispositivo PURE - il costo annunciato su Amazon è di 249,99 sterline - può ricevere via etere segnali FM/RDS, DAB e, con un prossimo upgrade al codec AAC+, il DAB+. Via Internet supporta stream mp3-4, Windows e Real. Previste anche connessioni iPod/iPhone e, tramite protocollo UPnP, con il personal computer.
Sensia è a tutti gli effetti un net device e prevede quindi una strategia parallela centrata intorno al portale The Lounge da cui gli utenti Sensia potranno scaricare un media server Win/Mac "Flowserver", ma soprattutto potranno usufruire di una directory di Web radio e canali Podcast che qualunque navigatore può consultare all'indirizzo Thelounge.com. Il portale include un player integrato che permette di riprodurre, da pc, qualcosa come 12000 stazioni (occorre naturalmente il plug-in compatibile con i vari stream). La guida online di The Lounge include molti podcast delle emittenti pubbliche di tutto il mondo e consente di accedere al servizio Listen Again della BBC. Trovate altre informazioni e screenshot su Sensia all'indirizzo del microsito dedicato da PURE al suo nuovo apparecchio, Touchmyradio.com.

Frontier Silicon's Venice 7 module now shipping in multiple products making it the fastest selling DAB module of all time

Hong Kong – 13th October 2009: Frontier Silicon, the leading supplier of digital radio technology, today announces its latest generation of unified receiver module is now shipping in multiple products from the world’s leading DAB/ DAB+/DMB-Radio manufacturers. An achievement made even more impressive given the module entered mass production just three months ago.
Products from a range of manufacturers including, PURE, Roberts and Grundig are entering retail stores in good time for Christmas giving consumers an unprecedented range of choice from entry level through to high end table top and Hi-Fi systems.
Anthony Sethill, CEO Frontier Silicon commented “The roll-out of Venice 7 has been truly remarkable. Within just 3 months from production start, we are now shipping hundreds of thousands of modules a month, as manufacturers realize the cost and power saving advantages of our multi-mode DAB/DAB+/DMB-Radio solution”.
Gerry Thorn, Product Director, Roberts Radio commented “Thanks to Venice 7’s ultra-low power, one of the first products Roberts is bringing to market is a hand-held pocket DAB radio.”
Daniel Todd, Managing Director, Bush Australia commented "Venice 7 has enabled us under the Bush and Grundig brands to be one of the first companies to launch a range of the DAB+ radios with iPOD docker into Australia."
As Europe progresses the switch off of analogue TV, an increasing number of countries are declaring their plans for digital radio migration from AM / FM to one of three variants of the Eureka 147 family. The UK is the largest and most mature market today with over 9.5 million DAB radios in circulation. Switzerland and Australia have launched their digital radio services using DAB+ and are already driving significant market growth. France is launching its digital radio service using DMB-Radio at the end of this year while Germany and Italy are expected to launch in the second half of 2010. The French and UK governments are leading the march to digital with both countries mandating digital switch over to conclude by 2013 and 2015 respectively.
Venice 7 is facilitating the digital radio switch over by providing radio manufacturers with a unifying receiver which supports all three DAB variants along with FM in a single low cost, ultra low power all-in-one module. It is the first fully compliant WorldDMB Profile 1 receiver solution enabling audio manufacturers to deliver a single mass market unified digital radio for Europe and Australia.
The Venice 7 module is compliant with WorldDMB’s Profile 1 specification and low power directives for Europe including the UK’s ‘Energy Saving Recommended’ scheme. Thanks to the Kino 3 baseband processor, Venice 7 is able to demodulate, audio decode and drive an intuitive user interface supporting DAB, DAB+, DMB-Radio and FM in battery and mains operated products. It includes all interfaces necessary for a fully functional radio including iPOD / iPhone docking, needing only power supply, display, keypad, audio amplifier and speakers to complete a product. The module is footprint compatible with the world’s best selling DAB/DAB+ solutions Venice 5 and Venice 5.1 – this means radio manufacturers have a fast-to-market upgrade path to offer all major digital radio standards without the need to redesign their product.

BBC iPlayer, download di tv e radio anche su Mac/Linux

E' una notizia di stampo molto televisivo ma solleva questioni mediatiche digitali che non possono non interessare anche noi "radiofonici". Come promesso, i BBC Labs hanno reso disponibili - per ora in beta per gli iscritti alla apposita sezione dei Labs - le versioni Macintosh e Linux del famoso BBC iPlayer, l'applicazione che serve per guardare la tv sui computer, i telefonini e altri dispositivi "connessi". O meglio, hanno reso disponibile la versione di questi player abilitati alla funzione di download dei programmi sulla propria macchina. Al momento del lancio di iPlayer, nel 2007, questa funzionalità era disponibile solo per la versione Windows.
Al di là degli aspetti estetici (iPlayer è bellissimo), ci sono molte considerazioni da fare sul Web come piattaforma sempre più consolidata della televisione su IP. Fino a poco tempo fa sembrava che il modello IPTV basato su set-top box da collegare al televisore fosse ancora in grado di affermarsi in modo definitivo. Tra l'altro è un modello molto, molto amato dagli operatori telefonici, che grazie al set-top box possono controllare agevolmente l'intera catena di distribuzione (e pagamento). E invece, dopo che anche Joost ha scelto di fare la sua tv direttamente su Web senza neppure un software da scaricare, non sono più mica tanto sicuro che la IPTV STB-based abbia tutte quelle chances (tra l'altro mi chiedo come proceda la raccolta di abbonamenti all'offerta di IPTV nostrana).
L'intervento di Anthony Rose, dell'Online Media Group della BBC, è tutto da leggere perché vengono spiegate le scelte fatte su due aspetti fondamentali: l'uso del DRM (e quale sistema, anzi, quali sistemi sono stati adottati) e la decisione di abbandonare, per il download dei contenuti, il modello architetturale P2P a favore di normali connessioni HTTP. Dimenticavo, per realizzare l'applicazione client, la BBC ha utilizzato l'abiente SAAS (software as a service) Adobe AIR.

Introducing BBC iPlayer Desktop for Mac, Linux and PC

from BBC Internet Blog by Anthony Rose

When we launched BBC iPlayer back in Dec 2007, it has been available for streaming on Window, Mac and Linux computers. But if you wanted to download our TV programmes, well, that was PC only. Obviously that wasn't a satisfactory arrangement, and making our downloads available on Mac and Linux has been a major priority for us.
Today, we're really pleased to announce that BBC iPlayer downloads are now available for Mac and Linux as well, thanks to our new Adobe AIR-powered download manager, which we've named BBC iPlayer Desktop.
To the best of my knowledge we're the first major content provider in the world to offer DRM downloads to PC, Mac and Linux platforms. Getting there has been quite a journey - here's the story...

Why do we need DRM?

In the past we've been criticised for using DRM. Surely a public service broadcaster has a duty to make its content available for free, forever, without rights restrictions, to all UK users. Unfortunately, much as we share those aspirations, the reality is that we have to use DRM, for two reasons:

1. As part of the Public Value Test undertaken by the BBC Trust, a decision was made by the Trust that the BBC could only make iPlayer content available for 7 days after broadcast, or, if you downloaded a programme, that you could keep it for up to 30 days, or 7 days after first playback. This was in response to industry concern that allowing people to keep programmes forever would lead to a reduction in sales of DVDs, etc. The ability to provide this 'timed availability' for downloaded programmes requires Digital Rights Management - i.e. DRM. So, for this reason alone, any download solution that we provide requires DRM.

2. Our rights holders require that we protect their content, at least one reason for which is to allow them to sell that content in other markets. For example, BBC Worldwide generates around one billion pounds in revenue annually, much of which is from sales of BBC programming in other territories, on DVD, etc. Some of that revenue flows back to the BBC public service, offsetting license fee requirements. Additionally, US movie studios often mandate use of particular DRM technologies as a condition for licensing their content. Accordingly, making our content available without any rights restrictions, freely downloadable worldwide, would affect the ability of those rights holders to monetise their content in other markets, hence an additional requirement for DRM.

Which DRM?

The BBC was widely criticised for choosing Microsoft DRM, which we chose for the initial iPlayer launch, and have been using since. Various conspiracy theories abounded, but the simple fact was that at the time Windows Media DRM was the only viable digital rights management solution around. It was sufficiently robust, accepted by rights holders, free (some DRM solutions have hefty license fees), fairly easy to use, and worked on 90% of computers.
Since then, we've embarked on a long and arduous journey to find the perfect DRM solution, one that would work on all computers, would be easy to install, would be supported by a reputable vendor, would be acceptable to rights holders, that wouldn't incur significant costs to us, and that could form the basis for a next-gen download manager platform that will in due course, well, keep reading...
We evaluated a large number of DRM solutions, including some open and open-source solutions. Some offered Mac support but not Linux, others required that we make our content available in their store rather than in our web site, other (sometimes open-source) solutions appeared attractive and low cost, but require extensive development to create a tamper-resistant player and would have incurred hefty MPEG licensing fees for playback of H.264 content.
Ultimately, we chose Adobe AIR and Adobe rights management (FMRMS) as our preferred solution for our next-gen BBC iPlayer Desktop application.
So, have we 'switched' to Adobe DRM? Not quite. We continue to use Windows Media DRM for downloads to Windows Media-compatible portable media players, we Open Mobile Alliance (OMA) DRM for downloads to Nokia mobile phones, we use Adobe DRM for downloads to PC, Mac and Linux computers, and we may support other DRM technologies for playback on set top boxes and future IP-connected TV devices.
Although it would be nice to have to support just a single digital rights technology, the reality is that when you look across mobile, PC and TV platforms there's no 'one size fits all' solution, and so we end up supporting a range of content protection technologies.
Of course none of this is of interest to the user - you just want to watch your favourite programme with as little fuss as possible - and we think that our new BBC iPlayer Desktop has gotten us a huge step closer.

No more P2P

Another big change we made is that our new BBC iPlayer Desktop no longer uses P2P. Downloads now come directly from our servers, as direct HTTP downloads.
Why the move away from P2P?

Three reasons:

1. When the BBC chose P2P for downloads over two years ago, bandwidth was really expensive, and so P2P was seen as the only way of providing a download service at a sustainable distribution cost. But over the past year the cost of bandwidth has decreased by 90%, making direct HTTP downloads a viable alternative.

2. Some users told us that they didn't like P2P - it used their CPU, used their upload bandwidth, slowed their computer. Our new solution should not have those issues.

3. In the UK, some ISPs count both download and upload internet traffic in their usage calculations, which means that some users were hitting their monthly usage caps more quickly because of P2P upload traffic. Our new solution doesn't have that issue (of course if you download lots of stuff you may still hit you monthly ISP limits - but that applies not just to iPlayer content).

It should be noted that in the technology world nothing stays still for long, and by choosing to not use P2P today we're not making a statement that P2P is either good or bad - we're simply saying that the cost/benefit right now is in favour of direct HTTP downloads, perhaps in due course served from edge caching servers deep in ISP networks. However, in the future new requirements and new P2P technologies (e.g. P2P streaming) may lead to a re-evaluation of our preferred delivery options.

The timing

Months ago we promised that we'd have BBC iPlayer programmes available for download to Mac and Linux computers before the end of 2008, and we made it... just.
Getting a solution out that worked on Mac was the easy part... having a solution that worked on Linux as well was somewhat harder. It's no coincidence that BBC iPlayer was released on the same day that AIR 1.5 for Linux was released by Adobe, as this is the first AIR release that provides DRM support on Linux platforms.

Available today to Labs users

The version of BBC iPlayer that's out today is very much a beta product, with a number of known issues that we'll be working hard to fix right after the Christmas break.
For those users who have our existing Download Manager installed, we don't want to break something that's working really well, and so we've introducing our new BBC iPlayer Desktop in Labs first. That means that it's available to anyone who has signed up as a Labs user - to do so, simply head over to BBC iPlayer Labs.
We expect to move BBC iPlayer Desktop out of Labs and make it our mainstream download manager application in February.

Upcoming developments

Right now BBC iPlayer Desktop makes use of the same 800Kbps H.264 content that's used for our High Quality streaming option. We're working on improving that, to provide 1500Kbps H.264 content that should be close to television quality. So, starting around February, we expect to deliver substantially better quality for downloads (these 1500Kbps streams will also be offered for streaming, providing near TV quality in iPlayer).
After that, we plan to use our new Adobe AIR platform to provide a range of features that will, we think, produce a really seamless online/offline, browser/desktop experience. Key features that are coming up include:

- being able to download radio podcasts
- being able to pre-book download of your favourite programmes, including whole series
- getting a popup system tray alert when your favourite programmes become available
- on-demand an live radio streaming, on your desktop.

Basically, we're looking to use this new platform to bring BBC content much closer to your desktop... which is why we called it BBC iPlayer Desktop.

Anthony Rose is Head of Online Media Group, BBC Future Media and Technology.