Electronic Design

EiED Online>> Building A Multimedia Home Control Center, Part 2

The ATI TV Wonder Pro and HDTV Wonder come with some great video and PVR software but it tends to be oriented towards a PC user. Add another PC to the network that you would like to utilize the TV services of the media center PC and you will definitely want to check out SageTV. It has a great interface that you may want to use it even in a stand-alone mode.

SageTV Architecture
I found SageTV to be just the package I needed to complete the home media system since it was part of a larger home network rather than being the center of it. SageTV is essentially a professional PVR (personal video recorder) software platform that runs on Windows and Linux. It can operate in a client/server mode (see Figure 1) so scheduled recording and playback can be initiated from a remote machine. SageTV can also handle multiple TV cards from a range of vendors for simultaneous recording of multiple programs. Features like instant replay and TV schedules are available from all client platforms. Wireless remote controls are supported as well.

SageTV can act as a video server delivering content to other PCs or media delivery vehicles like Hauppauge’s Media MVP (see “Making More Of Your PC’s Video,” ED Online 11736). It also allows these remote systems to initiate scheduled recordings. The server support works well on a home media center that is designed to run continuously versus the typical PC that gets turned on and off.

SageTV is relatively inexpensive and you can download an eval version to check it out. It works with a range of TV boards including ATI’s and with a number of remote devices like the Media MVP (see Figure 2). It is also the only commercial package I found that can handle multiple TV boards.

I started out with the main SageTV application (see Figure 3). This is available for both Windows and Linux although the latter is designed for an OEM. Any experienced Linux user will have no trouble but a Linux novice will want to check out the online forums for tips and assistance. From a SageTV user standpoint, the user interface is identical.

SageTV runs on everything from Windows 98 through Windows XP as well as Linux. The latter version tends to be targeted at OEMs and more savvy Linux users. The user interface and system functionality is the same across platforms. You can mix and match client and server platforms as well. Recording works with any disk but it is more efficient if you have a hard disk with a 64Kbyte block size. This is ideal for large multimedia files but less efficient for smaller document files.

Installing the main SageTV application was uneventful. The first thing the program does is walk through the setup wizard. SageTV supports plug-ins but only the weather status is included with the package. The wizard asks for your location so it can grab weather information off the Internet. It also uses an Internet connection to access TV schedule information. You need to specify your location again and the type of channels (cable, over-air, etc.) and which channels are to be displayed. The remote control to be used with the main PC and TV cards in the PC are also specified via the wizard.

SageTV User Interface
Initial setup takes a few minutes. Running the user interface provides a menu that is easily readable on a television screen at a distance. The mouse can be used to select items. All functions are available via the remote control as well using arrow keys and the select/enter button.

You notice the difference between the SageTV interface and a PC-based PVR system almost immediately. SageTV is designed to the full screen and the text assumes a low resolution TV screen since HDTVs are still relatively new. This means fonts are larger, the number of options is lower and the menu system is screen oriented, not task bar oriented. The latter is conducive to mousing and preserving screen real estate for other aspects of the program. The former is better for handheld remote control operation where cursor and select buttons are more common.

The SageTV interface is also on par with other commercial PVR systems. This means it is consistent and relatively easy to use. The only two gripes I have are that there is not enough online help and accessing some setup options requires a bit of navigation. The former is really an issue when first starting to use the system or when dealing with the setup options.

The SageTV screens tend to have half a dozen options to select from and navigation for all options is possible using a remote control unit. On a PC, the mouse can be used to select any option directly and you can optionally have the on-screen selection cursor follow the mouse. This is more personal preference and it is selectable.

I was able to use the SageTV interface to view and record TV programs (see Figure 4), view images and listen to music files. Images can be viewed in slide show mode. DVD playback is possible although not from remote clients. Recording is possible when the program is running, in standby mode, or if the SageTV server is running.

Recording can be initiated in one of three fashions. Top priority is manual or explicitly scheduled recordings. Favorites come next followed by Intelligent recording. Systems with multiple TV capture boards like ATI’s TV Wonder Pro will use these priorities to determine what boards will perform a particular function.

Manual scheduling can be done using the TV program guide (see Figure 5), specifying time/date or while watching a program. The latter starts from the point you initiated the recording. Favorites are selected in the same fashion but SageTV handles subsequent recordings in a different fashion. For example, it will record the same program each time it is available unless the particular episode has already been recorded even if the episode has been recorded, viewed and deleted.

I really liked intelligent recording. This automatically records programs based on your likes and dislikes. Of course you need to specify whether you like or dislike a particular show but this is easy using the menu system. It can be done after the fact when you view programs recorded in this fashion. SageTV tracks the shows available and your preferences and records shows it thinks you will like. SageTV manages disk space such that manual and favorite shows take priority over intelligent recordings so nothing is done if space limitations would be exceeded. SageTV automatically deletes intelligent recordings if more space is needed.

The recording features ware very easy to use. I found having a separate disk partition for videos was the easiest way to manage space. It also allowed different block sizes to be used in this partition and the main partition.

My kids had no trouble figuring out the system without even knowing there was documentation. They were scheduling recordings immediately and preferred channel surfing via the program schedule. The current program can be displayed at that time.

Things get more interesting when more platforms come into play.

Multi-Platform SageTV
SageTV actually splits the recording and playback into two distinct operations but transparently merges the two so it can implement features like instant replay and watching a program while it is being record. I really like the latter because you can skip over commercials assuming you start watching after the program recording has started.

Additional platforms come into play with a SageTV server with zero or more TV capture boards and disk storage. The remote platforms run the SageTV client interface but communicate over the network to stream media from the server and to control the server’s program scheduling. The client interface does not differ from the usual, single user client interface.

The main limitation with multiple devices is the number of TV capture cards on the server and the performance of the server. Keep in mind that a capture card can only perform one action at a time so if they are all being used to watch or record TV programs then only those programs can be viewed at that time by the clients. Of course, two clients can view the same program and utilize the same resource. There is no limitation on the number of clients that can play back a recorded program other than the performance limitations of the hardware.

Of course, there is no such thing as a free lunch. Our multimedia system only has space for a single TV card and it will support one remote client. Luckily, from an architecture standpoint, it is possible to build a higher performance SageTV server system with all the TV cards for the system including pulling the TV card from our multimedia system. Our multimedia system would then run the remote SageTV client and still have the same functionality as before.

Setting up a multiple client system, also called Placeshifter clients, is not much more difficult than installing SageTV on multiple systems. It was a simple matter to link to the server during the setup process. Remote control configuration is obviously per client although it can be interesting due to remote control crosstalk if clients are close to each other depending upon the remote control technology being employed. Remote access can be password controlled by user and it can operate across the Internet with prior firewall configuration. Licensing is based upon the number of active clients.

SageTV also supports non-PC extenders like Hauppauge’s MediaMVP. It replaces the software on the MediaMVP with a special SageTV client. The MediaMVP is strictly a playback device so the SageTV server must have a TV capture board to watch live TV or to record programs. Of course, the MediaMVP is designed to plug into a TV with its own tuner for watching live TV is often done using the TV tuner. Still, I found myself switching between the two. I would setup a program to be recorded and simply drop back to it when the other program went to commercial. I could pause the playback of the program being recorded as necessary and then skip over commercials. It is almost possible to watch two programs in this fashion because there are so many commercials in some programs.

The MediaMVP client installation is a bit more manual than the regular SageTV installation. In fact, you need to install the client again on the server PC because the client interface run on the server is actually echoed on the MediaMVP system. The server client application can be put into standby mode so it does not clutter up the screen but the MediaMVP uses the client resources all the time. You can play battling remotes via the client window and the mouse.

One very nice feature of SageTV for platforms like the MediaMVP is transcoding. The MediaMVP supports hardware decode of formats like MPEG-2 but there are others it does not. SageTV simply decodes these formats and encodes into a format the MediaMVP can handle transparently.

Yet one more option is the SageTV Studio. This tool, licensed separately, allows editing of recorded programs and saving them via a DVD recorder. SageTV has a programming API that might be of interest to OEMs.

Overall I was extremely impressed by the ease of use and feature set of SageTV. I was able to play VOB files I had backed up from DVDs as well as MPG files from sources other than SageTV recordings. Right now the Western Digital drive is filling up with recorded programs.

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