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USB2 Video Capture and Recording:
    Pinnacle PCTV Deluxe  (4/2003)

    by Douglas Dixon

USB and FireWire
Video Compression

Pinnacle PCTV Deluxe
Video and TV Viewing
Recording and Timeshifting
Recording Settings
VCD and DVD Burning

USB2 Video
References

Faster, faster! More power! In early 2003, you could load up a system with a 3 GHz processor, 1.5 GB of system memory, and a 200 GB hard drive. All this is wonderful, but most basic system requirement for video users still is the need to capture full-rate full-resolution video into your computer.

The recent popularity of the FireWire interface has provided a convenient plug-and-play solution for connecting DV digital video camcorders to a computer. FireWire, as its name suggests, is plenty fast enough for transferring full-quality digital video. However, it was designed for use with intelligent (i.e., more expensive) digital peripherals, and DV camcorders do not address the need to capture video in various analog formats or to connect to a TV tuner.

   

Enter the next leap in peripheral interfaces: USB2, the new version of the USB interface, also known as USB 2.0. While the original USB (now USB 1.1) interface was originally designed as a Universal Serial Bus for lower-speed peripherals such as keyboards, printers, and scanners, it also has found a niche for low-resolution video capture devices. For example, the ATI TV Wonder USB provides 320 x 240 analog video capture and a 125-channel TV tuner for $79 (www.ati.com).

The new USB2 interface ups the transfer speed from 12 to 480 Mbits per second, to the same range as FireWire. This enables a new breed of low-cost analog capture devices like the new Pinnacle PCTV Deluxe, with full-resolution video capture over USB2 for $199. The PCTV Deluxe includes hardware MPEG compression, so you can capture live video directly in MPEG-1 Video CD and MPEG-2 DVD formats to burn to CD or DVD. Besides real-time live television viewing, you also can use the PCTV Deluxe as a digital video recorder to capture scheduled programs to hard disk, and even time-shift a program to watch the beginning as it is still being recorded. Not bad for an interface originally designed for keyboards!

USB and FireWire

In the bad old days, just a few years ago, good video capture required a dedicated analog capture card, which meant opening up your computer case and fussing with finicky hardware and software. There were attempts to use the existing computer ports for video capture, by chaining to the parallel port (you could print, or capture video, but not both at the same time) or even through a SCSI interface. But video capture really needs a plug-and-play solution, especially for laptops.

And then there is the speed issue: High-speed parallel ports provide data rates of up to a few MBytes/sec., in the same range targeted by the original USB1 specification at 12 Mbits/sec (1.5 MB/s).

(Note that transfer rates are often specified in bits per second -- with a lowercase "b" -- while storage capacities are typically specified in Bytes -- with an uppercase "B". However, some familiar rates are typically quoted in MB, so we will convert bits to Bytes for comparison.)

Meanwhile, over the years the SCSI interface has been extended by doubling from 5 MB/s to 10 to 20 to 40 to 80 to 160 MB, from Fast to Wide to several generations of Ultra. The FireWire interface (originally specified under the name IEEE-1394) then offered a similar interface with plug-and-play capabilities at 100 to 400 Mb/s (12.5 to 50 MB/s). With DV video compression at 25 Mb/s, digital camcorders work well with the FireWire data rate.

To this point, USB and FireWire are complementary technologies. USB1 was designed for lower-cost low and medium bandwidth applications such as keyboards, mice, printers, scanners, and audio (www.usb.org). FireWire, with a more complex protocol, was designed for high-bandwidth and more expensive applications such as external hard disks, DVD burners, and digital video (www.1394ta.com).

Enter USB2, also known as Hi-Speed USB, with a data rate of 480 Mb/s (60 MB/sec), or slightly faster than FireWire. With the faster rate, new external disk drives and even video cameras are starting to include USB2 interfaces, often in addition to a FireWire interface.

Video Compression

Even better, this opens the possibility of low-cost USB-based video capture devices that can deliver full-resolution full-rate video. Full uncompressed video is still too much data to capture, process, and store in a personal computer, so it is useful to compress it during capture. With effective compression, the video can be significantly reduced in size, so it can be transferred within the computer and saved to disk and read back again without swamping the system. Video compression algorithms including DV and MPEG can squeeze the video data while still retaining good visual quality, and today's computers can easily decompress and display compressed video in real time.

DV video is compressed at a fixed rate at around 25 Mb/s. The MPEG-2 format used for DVD and many digital cable systems supports a range of more aggressive compression rates, typically ranging around 9 to 3 Mb/s for excellent to good quality. MPEG is therefore a nice match for analog capture devices, since the data rate can be adjusted by the user to trade off storage size and quality. As a bonus, the video can be captured directly in a format suitable for burning to DVD (MPEG-2) or Video CD (MPEG-1).

While the USB1 interface data rate of 12 Mb/sec can accommodate real-time video streams of up to around 6 Mb/s, in practice USB1 capture devices are designed to support quarter-stream motion video, and sometimes full-resolution stills. USB2 provides a lot more headroom to support higher compression rates, and therefore can be used to deliver full-resolution full-rate video.

Pinnacle PCTV Deluxe

The Pinnacle PCTV Deluxe, introduced in November 2002 for $199, is an external USB2 analog video capture device with an integrated TV tuner (www.pinnaclesys.com). The unit is about the size of a VHS tape, and includes front-panel input connectors for composite video, stereo audio, and S-Video. The back panel has a TV input for antenna or cable, and the USB and power connectors. The product also includes a programmable remote control.

           

For comparison, the Adaptec VideOh! DVD is another USB2 video capture product, with MPEG-2 video capture and DVD creation software, but without TV tuning, for $179 (www.adaptec.com).

The PCTV Deluxe software package includes the main PCTV Vision application that provides viewing, capture, and burning, and the TRex video format conversion tool. PCTV Deluxe also provides a TWAIN interface for still image capture.

The installation process is plug and play. You install the drivers and applications, and then Windows should recognize and set up the device when you plug it in. Pinnacle also includes the PCTV Assistant application to verify that your system meets the product requirements (Windows ME, 2000, or XP, with DirectX 8.1), and that the product has been properly installed.

The PCTV Vision application packs a lot of functionality behind a simple TV screen appearance, including a player for video or TV, video capture and still grab with a gallery, digital video recorder with time-shift, recording scheduler, and VCD, SVCD, and DVD burning.

Video and TV Viewing

The main PCTV Vision window has a TV Screen area with basic viewing controls below: Channel Display, Channel Up/Down, and Volume control. You also can use keyboard shortcuts to change channels and adjust the volume. The display size is adjustable, so you can shrink it to a corner of the screen, set it to always be on top of other windows, or have it fill the screen.

           

Unfortunately, changing to a new channel is a bit sluggish -- a second or two -- as the digital data works its way through the MPEG compression pipeline, so you really do not want to use this interface to flip consecutively through a hundred channels.

Similarly, PCTV Vision can display a Channel Preview Matrix window so you can view a grid of consecutive channels all at once (you can set the grid dimensions), but it takes a while to surf through the channels to fill the grid.

To define the channel list, the PCTV Deluxe has an auto-scan function to find the available channels. You can also enter names for the channels, add and delete channels, and organize them alphabetically, in groups, or under Favorites. You can also choose to view the video from the composite and S-Video inputs.

Recording and Timeshifting

Beyond viewing live TV or video, PCTV Vision has extensive recording capabilities like a digital video recorder using its built-in MPEG compression the. To control recording, click on the bottom of the PCTV Vision window to slide open the recording control panel. At any time, you can click the red Record button to start recording the video to disk to save to a file.

PCTV Vision also includes a Scheduler dialog to program video recordings. Like a VCR, you can schedule the channel and time to be recorded, for single or repeated recordings, and then review and update the list. You do need to leave the PCTV Vision application running in order to have it start recording at the specified time.

Click the Record Snapshot button to grab a still image of the current video display. PCTV Vision also includes a Gallery window to view thumbnails of your recorded Videos and Snapshots. From the Gallery, you can view details on the media, play, rename or delete the files. The Gallery also provides VCD and DVD burning (see below).

You also can click the TimeShift button to enable timeshifting while you are watching. PCTV Vision will then record the video to a temporary file so you can pause and even skip through the existing recorded video even while the recording of the live broadcast continues. You can use the Position Controller slider to move to a different portion of the video, or the Jump buttons to skip a preset period of time. You can switch between viewing the live source and the timeshifted / recorded material, and can save timeshifted material to a file.

Recording Settings

PCTV Vision provides a Settings dialog to control and customize the viewing and recording. It includes tabs for setting Channels, including defining names and groups, Colors, including brightness and sharpness, Video input format, including deinterlacing and noise reduction, Audio input format, including mono and stereo, Capture, TImeshift, and Special.

Use the Capture tab of the Settings dialog to specify the video format, resolution, and quality to be recorded. You can choose a preset setting, including Video CD (VCD) for MPEG-1 at 352 x 240 resolution (NTSC), Super Video CD (SVCD) for MPEG-2 at 480 x 480, and DVD MPEG-2 at 720 x 480. For DVD recording, the standard preset records at 6 Mb/s, and the DVD Longplay preset records at 3.5 Mb/s, sacrificing some quality for reduced file size (or longer recording time at the same size).

You also can choose Custom settings for MPEG-2 compression: Bit Rate (from 2.5 to 9.5 Mb/s), and Size (352 to 720 x 676 resolution). You also can define the directory in which the captured video is stored.

Use the Timeshift settings to specify the maximum amount of time and the maximum file size to be used for the timeshifted video data.

VCD and DVD Burning

Once you have recorded video clips, PCTV Vision also can burn them to VCD or DVD disc. From the Gallery window, first select the recording format: VCD, SVCD, or DVD, and then click the Burn button to display the Burn dialog.

Once the Burn dialog has been opened for a specified format, only files saved in a compatible MPEG format will be selectable in the Gallery window. You then can drag and drop files from the Gallery or other locations to the Burn window to create a list of files to burn to disc. Finally, click the Burn button to burn the selected files to disc.

If you want to burn other files, or burn your recordings in a different format than how they were captured, you can use the included TRex application to convert between different formats. You also can create a list of files to be converted together.

TRex can read audio and video file formats that are supported on your Windows system (i.e., that you can play with Windows Media Player), including AVI, MPEG, and ASF. It then can convert to a variety of formats, , including Wave and MP3 audio and MPEG-1, MPEG-2, AVI-DV, and even AVI MPEG-4 video, again if the associated compressor is available on your system. With some formats, TRex provides a basic Speed/Quality control that trades off processing time and video quality.

USB2 Video

As USB2 is becoming more common as a standard interface on new computer systems, you also can add USB2 support to an existing system with an interface card, much like FireWire cards have become popular for connecting to DV camcorders. Dual port cards with both FireWire and USB2 interfaces are also becoming available, such as the Adaptec DuoConnect, a 4-port USB 2.0 and 3-port FireWire combination card for PCs and Macs for $99 (www.adaptec.com).

   

With new technology, unfortunately, does come some shaking out. While the Pinnacle PCTV line and Vision software are mature product lines, and have worked well for me in previous products, the combination of the USB2 interface and Windows XP did have some glitches in the first version of the product that I reviewed. The installer generated several Windows XP certification warnings, and the Vision software would intermittently respond very slowly or even hang.

These kinds of issues should be worked out in the early 2003 software update that will be available when you read this. The update should also include an electronic programming guide (EPG) to help with scheduled recordings.

The Pinnacle PCTV Deluxe is the beginning of a new generation of video capture devices, offering full-quality MPEG video with plug-and-play simplicity. Finally, full-resolution full-rate video capture is available from a low-cost external box that you can easily share among desktop systems, and even use it with laptops. That should be fast enough for us, at least for the moment.

References

Pinnacle - PCTV Deluxe
    www.pinnaclesys.com

Adaptec - VideOh! DVD
    www.adaptec.com

ATI - TV Wonder USB
    www.ati.com

1394 Trade Association (FireWire)
    www.1394ta.com

USB Implementers Forum, Inc. (USB-IF)
    www.usb.org