Active-TV Technology for iPhone and iPod touch

Active-TV Technology for iPhone and iPod touch
Navigate YouTube

Navigate YouTube available at iTunes App Sore

An easy to use iPhone and iPod touch App that enables both new and advanced YouTube users to get the best from YouTube.

Browse video Standard Feeds, Categories, Channels and Playlists. Then organize new videos into your own favorites and playlists. Make playlists private or public. Subscribe to other user's playlists and video collections for future viewing. Subscribe to videos matching search-words.

Look at publicly viewable favorite videos, playlists and subscriptions based on your YouTube friends, family and contacts. Send and receive video links with YouTube contacts via YouTube video messages.

Search for new videos tagged for your language or geographical region, using local keyboard. Explore for new videos via easy switching of user ID to the owner of interesting videos - then explore their world.

All actions are kept in sync with PC, Mac or Apple-TV access to YouTube. Available at Apple App Store.

active-TV technology for PC

active-TV technology for PC
Windows PC based home network

Tuesday, February 26, 2008

Adding a Video RSS feed or Torrent-Video to TV-web Browser

The Issue: Turning an RSS video feed, or a feed for torrent-based videos into a TV-web page for browsing at the TV has been made easy. In the interest of keeping up with the demand for new channels, the notes below provide a step-by-step implementation guide for the engineer with some JavaScript knowledge.

Solutions: The example code is available for download. When you complete a new TV-web channel and publish it, send me a link so I can help spread the word.

Behind the scene: The growing use of RSS distribution for video via torrents or streaming can be easily expanded from PC users to TV viewers. In hardware terms, what is needed is a TV that supports browsing of TV-formatted web, i.e. TV-web. An active-TV technology enabled TV or Set-Top Box is just one such device.

If you are not interested in torrent support, skip the following section and start reading from the Adding an RSS Feed section.

Configuring uTorrent Support
(Please see updated blog entry on this topic) uTorrent is a tiny bittorrent client-engine for the PC. The uTorrent TV-web page contains JavaScript which communicates with the uTorrent software running on a networked PC. If, for some reason, the TV-web page can’t communicate with the uTorrent software, then the message below appears on the TV. This usually indicates that the uTorrent engine has not been started before the TV-web page was accessed. (Before using the bittorrent TV-web page, uTorrent should be downloaded and installed on the supporting PC.)

There may be other reasons the TV-web page can’t successfully communicate with the torrent engine and require a little diagnostic work. The uTorrent software can be controlled via a browser interface. This enables remote browser access to a PC running uTorrent. The uTorrent “Preferences” must be correctly configured for this to work. The remote TV-web page assumes the “incoming connection” is set to the default port, 12060. See the setup option below.

The uTorrent Web UI interface enables remote login to the torrent PC. The remote login ID must be set to “active-TV” with password “pass”. This is the initial password. It can be changed to your own preference; however, make sure the ID on the uTorrent TV-web Settings page is set to the same value.

After a torrent is complete, uTorrent can move the downloaded files to a “completion directory”. The TV-web software does not care if this option is used, or what directory is identified, but it is best to use a directory which is accessible by one the media servers used by the system.

Media Servers currently popular with active-TV technology are provided by D-Link, TVersity, Microsoft and Media Mall. The D-Link server is included in basic install-software for the DSM-520. It enables access to a networked PC’s file system. The server software on the PC must be set to indicate what part of the file system is to be shared with the DSM-520. Use of the D-Link server does not require active-TV software to be in use by the DSM-520.

Similar to the D-Link server, the TVersity server can also work with the basic UPnP-DLNA services of the DSM-520 or other networked media players. This means the TVersity server can give a networked TV access to the PC file system without active-TV support software running on the PC or TV. Additionally, TVersity can give a basic UPnP device access to RSS feeds; But in this case the TV UI is determined by the local device and not by an associated TV-web page. However, TVersity also has an active-TV conforming TV-web page which supports access to the PC file system, but this time via a TVersity TV-web page.

The MediaMall server is another option when remotely accessing the PC file system. In this case there are only TV-web page interfaces to the PC’s file system. These are found under the “More Programs” – “My video”, “My Music” and “My Photos”.

PC media servers are programmed to scan the shared portion of the file system at regular intervals. In this way they find changes to the file system and the arrival of new files to be shared. After a torrent download has completed it is not available at the TV until after the next media server “scan”. When doing so, the uTorrent TV-web page ‘asks’ the torrent engine for the location of the completed torrent. In this way the torrented video is immediately available for viewing via access from the uTorrent TV-web page.

Take care with the access permission applied to torrented files. The DSM-520 logs into the PC just like any other PC user. If a torrent is started from a TV-web page, then downloaded files may have access restrictions imposed on other PC login IDs.

Adding an RSS Feed
The uTorrent TV-web channel, or any RSS- fed TV-web page, has a link to a setup page, partially shown below. Each of the 3 menu entries consists of a left or A-part, which generally selects the torrent or video source. The right or B-part is used for further selection from within the chosen A-part source. Those planning on extending RSS video or torrent feeds must know how to make the simple changes to the HTML file for the channel’s TV-web page.

For the menu-3 entry above, the source is “BitTorrent” and the sub selection is “TV”. The list of possible entries for A-part selection is defined by the Torrent_A array in the uTorrent_16x9.htm file. To add a new A-part entry, corresponding to a new RSS feed, a new identification-string must be included in the Torrent_A array

var Torrent_A = new Array("Democracy Now", "torrents”, "BitTorrent");

The support software calls the getMenuB() function to determine the possible B-part selection – given a chosen A-part. This function must be expanded to include any new RSS feed. The getMenuB() function need only return an array of part-B options; such as returning the array BitTorrent_B shown below.

function getMenuB( A_choice) {
if (A_choice == "BitTorrent") {
return BitTorrent_B;

var BitTorrent_B = new Array("TV", "Movies");

Once a user of the settings page completes final selection for each of the 3 menu entries, the setAB() function is called to establish the RSS URLs to be used with each menu entry. Adding a new RSS feed would require corresponding expansion of the setAB() function. The logic is quite simple, as shown below.

function setAB( column, A_choice, B_choice) {
if (A_choice == "BitTorrent"){
if(B_choice == "TV" ) {
column_url[column -1] = "";
else if(B_choice == "Movies" ) {
column_url[column -1] = "";

Parsing the RSS Video Feed
Using the RSS feed’s URL, an XML documented is downloaded from the RSS server. To study an XML layout, it can be saved to the PC as an ..xml file and examined by opening with Microsoft’s IE7 browser. There are differences between the formatting of each RSS feed. But typically, each video entry in the XML table or listing looks like the example below. In this case the start of each video entry is marked with the <item> tag. The “Willie Nelson” entry below is from an RSS feed from

- < item>
< title>Willie Nelson: Austin City Limits< /title>
< link>< /link>
<>Songwriting legend (and biodiesel proponent) Willie Nelson performs live at the Austin City Limits.< /description>
< pubdate>Tue, 08 May 2007 22:17:28 -0000< /pubdate>
< comments>Seeders:0 Downloaders:0< /comments>
< enclosure url="" length="38718489" type="application/x-bittorrent">
< /item>

The TV-web page’s support code uses JavaScript to exact the relevant date for each video entry. The fillVideoArray() function is used for this task. It must be expanded to include support for passing a new RSS feed.

function fillVideoArray ( column, first_video, quantity) {
if(menuAB[column -1].A_choice == "torrents" ) {
return torrentsFillVideoArray(column, first_video, quantity);
else if( menuAB[column -1].A_choice =="BitTorrent") {
return bitTorrentFillVideoArray(column, first_video, quantity);

The fillVideoArray() function is used to produce an array of menuEntry , know as the Video array. Each entry has a title, description, rating and so on. All that is required is ‘walking’ thought each XML entry and extracting the relevant data for entry into the Video array.

function menuEntry ()

The essential part of the parse routine is below. There are two important routines to understand: getElementsByTagName() and getAttribute(). For example, the tag-name “enclosure” contains the URL for the video. Some tag-names don’t have attributes and getElementsByTagname() is used alone to access the required Video entry – such as “title” in the example. In the case of the video URL, the URL is an attribute of the “enclosure” tag. This requires use of the getAttribute() to exact the URL data.

video_index =0;
for (var i=0; i<(xmlElement.length + skip) & video_index < entryitem =" xmlElement[i];" image = "BitTorrent.png" rating=" 0.0;" titleitem =" entryItem.getElementsByTagName(" title =" titleItem[0].text;" descriptionitem =" entryItem.getElementsByTagName(" description =" descriptionItem[0].text;" enclosureitem =" entryItem.getElementsByTagName(" duration =" Math.floor(" url = "torrent@" dateitem =" entryItem.getElementsByTagName(" date =" dateItem[0].text;" date =" date.substr(0,">

Note in the above example there is no per-video image data or rating. In such case an empty string ( “” ) or 0.0 value can be used for the corresponding Video entry, or some more useful value can be created or inserted. The “duration” entry has been filled with the size of the torrent file, this entry normally contains a string indicating the run-time of the video. It is important to note that in this bittorrent example the video URL has the string “torrent@” prepended. This is only required for torrent videos. When parsing an RSS feed for normally streamed video, which are to be viewed immediately, “torent@” should not be added to the video URL.

The TV-web is used to display the Video array information for each video menu entry. The image above shows the information extracted for the “Willie Nelson” example.

With menu settings: “torrent” – “active torrents”, information about the progression of video torrents is reported. This is only provided for torrents containing video or other media file. It is possible to torrent, say, an .exe file; but the torrent progress would not be reported, as the file is not for TV access. So, perhaps RSS filtering above should exclude .exe files.

As this proof-of-concept is further developed, more features and support for additional torrent engines will likely be added. For now, however, it has been proven that torrents listings can be viewed, selected, download and watched -- all from the TV, a welcome step towards making the pleasures and ease of 'catch-up TV' viewing, heretofore only available on the PC, now available directly on the TV. The steps outlined above, show how to add addition RSS video sources to a TV’s channel listings.

Feedback, corrections and comments welcome. Contact me for more information or support with active-TV technology development.
Daniel Mann

Tuesday, February 5, 2008

How many TVs in a home network can simultaneously surf internet video

The Issue: Internet video viewing is popular with PC users. As active-TV technology brings viewing to the livening room TV, what limitations may be imposed on simultaneous video access around the home?

Solutions: Active-TV technology pushes the software support burden onto a networked PC, so as to mostly eliminate the cost and maintenance burden at each TV. Synchromesh Computing has benchmarked the load the TVs place on the supporting PC. Processing TV-web requires the support of complex software, but the processor burden is typical very small.

Behind the scene: As TV System-on-Chip (Soc) devices offer increasing support for advanced video codecs, it is clear that the most restrictive component of an active-TV technology home-network is the broadband service to the home. Currently, the PC can be used to transcode non-native video into a format decodable at the TV. Support for this feature appears to be the biggest processor burden placed on the supporting PC.

Synchromesh Computing used a system of up to 5 D-Link DSM-520 Digital Media Adapters (DMA). They were connected by wire to a home router. The home PC or laptop was also connected to the router, but by either a wire or 802.11g wireless connection. Each of the active-TV enabled TVs was simultaneously viewing YouTube video. Synchromesh told me that they did not think wirelessly connecting all of the DSM-520s would effect YouTube viewing at the TV. They did not test a completely wireless network as their primary interest was in determining the load on the home PC or laptop rather than the home network.

Three different PC systems were used for the test (see table below). These supported greatly different computational power levels.

The test was to determine if the PC had the computational power to support all of the 5 TVs, or some reduced number. Technically it is possible to support more than 5 TVs, but an upper limit of 5 seems adequate for home use.

The chart below shows the number of active-TV technology clients (D-link DSM-520) supported by a PC using Windows XP, while the PC assisting the TVs is also being used simultaneously to surf the web and view YouTube video.

( © Synchromesh Computing )

The chart below shows the number of active-TV technology clients (D-link DSM-520) supported by a PC using Windows Vista, while the PC is assisting the TVs and is simultaneously being used to surf the web and view YouTube video.

( © Synchromesh Computing )

The results indicate that a dual-core PC or Laptop computer can support 5 TVs while still being used to browse the web. A single-core low-end PC restricts the number of TVs supported to 1 or 2, depending on the PC operating system on type of home network used.

The use of YouTube video is interesting as it is currently available in Adobe Flash video (FLV) or H.264. Neither of these are natively decoded by the DSM-520. In the benchmark case, the video was accessed in FLV and transcoded to MPEG2. The use of MPEG2 results in relatively high bandwidth consumption but good video quality.

When the internet video is available such that no video transcode is required, then the burden on the PC is obviously dramatically reduced or eliminated in terms of the video trancode load imposed. This will increasingly be the case, but for now, it is good that the PC can ensure that the TV user is not restricted.

But what if the PC user is placing a heavy load of the PC’s CPU, such as running a complex game. How does this limit the TV’s ability to access YouTube? The chart below shows the number of active-TV technology clients (D-link DSM-520) supported by a PC using Windows XP, while the PC assisting the TVs is simultaneously used to play World of Warcraft – a 3D PC game.

( © Synchromesh Computing )

The results indicate that when playing a complex game, a low-end dual-core PC is only able to “spare” enough “CPU-cycles” to support 3 or 4 TVs requiring YouTube-quality video transcode. As with the lightly loaded PC tests, a high-end dual core PC is able to support 5 TVs -- even when it is heavily loaded with other activity.

The results are interesting to the engineer. But in practice, unless you have a relatively old or slow PC, the biggest restriction imposed on multiple TV access to internet video is the bandwidth available through the home connection. “Better quality” internet video can use more than 0.7MBps of bandwidth. Supporting 5 channels might require 3.5MBps bandwidth; which is certainly more bandwidth than currently available to many home users in the US. It would be best to first test your ISP bandwidth to determine if it has the capacity to support so much TV-web browsing.

Feedback, corrections and comments welcome. Contact me for more information or support with active-TV technology development.
Daniel Mann