3.20 Changing the resolution during capturing with active video overlay
Avoid changing the resolution during capturing AVI files with enabled
video overlay. The video overlay can be enabled in VidCon32 or in the
Premiere capture program.
3.30 Interrupt Sharing
This miroMEDIA PCTV version supports PCI interrupt sharing. This function is
necessary if the motherboard allocates a single interrupt to all PCI slots.
In this case, all PCI devices have to share one interrupt which means that
every driver has to check if the current interrupt comes from its device.
If this is not the case, the driver must not handle this interrupt and has to
pass it to the next PCI device. If only one of the devices involved (or its
driver) fails to do so, the system will not function properly. Because the
devices which are mostly used for recording and playing back video are SCSI
hard disks and SCSI controllers, we test the behavior of SCSI controllers.
Under Windows95, we tested miroMEDIA PCTV (pro) together with several SCSI
controllers.
3.40 Hard disks
Windows 95 supports 32-bit hard disk access. Please check in
Control Panel/System/Device Manager whether your hard disk drive or your SCSI
controller has been detected by Windows95 correctly. If not, the data transfer
rate of your hard disk will not suffice for a satisfying quality when
recording and playing back video.
If possible, install a second hard disk for capturing and saving all of your video clips. You can save temporary files to your system hard disk or another partition. Windows 95 accesses system files during recording and playback,. If these files are located on the same hard disk as the video clips, the head has to be
repositioned, which leads to one or more dropped frames (unsmooth playback).
3.41 Enhanced-IDE hard disks
With some E-IDE hard disks, high data rates result in an unsmooth playback
when playing back AVI files, because the hard disk is recalibrated while a
file is read. This is not a miroMEDIA PCTV malfunction but is due to the
functionality of your hard disk and the other system components.
If you received a disk with special busmaster drivers with your hard disk, please
install these drivers in your system, because the disk performance will
be improved considerably.
Please ensure that the correct PIO-mode has been set in the mother bios for the hard disk.
3.50 VidCon32
For using the miroMEDIA PCTV (pro) in Windows 95, we recommend VidCon32
for capturing AVI files. VidCon32 will be copied during installation of the
miroMEDIA PCTV (pro). VidCon32 fully supports the 32-bit capture-class, so you can
attain substantially higher data rates during capturing. Ensure that the option "No master" is enabled in the VidCon32 menu under "Edit| Preferences| video and audio synchronization".
To attain maximum performance during capturing, shut down any programs that may be running in the background.
3.51 VidCon32 and the NTSC standard
Before capturing NTSC movies with VidCap32 you should set the "frame rate"
in the Capture/Video menu exactly to 29.97 frames/s and not 30 frames/s !!!
Only with this exact setting it is possible to capture NTSC movies lip-synch for
a long period of time.
3.52 VidCon32 and the PAL standard
In some systems, it may be impossible to capture smooth video although the frame rate is set to 25
frames/s and there is sufficient system performance (CPU and hard disk).
In this case, we also advise setting the "Frame rate" to 30 frames/s under PAL in the menu under
Capture | Video.
3.53 VidCon32 and Media Player
We advise against starting VidCon32 or any other video capture program while using Media
Player to play back AVI files captured with the miroMEDIA PCTV (pro).
miroVIDEO PCTV (pro) does not permit simultaneous capturing and playback of AVI files.
If you want to activate both devices at the same time, then you MUST start the Media Player first.
3.54 Known bugs with VidCon32
By default, VidCon32 sets the capture file to C:\CAPTURE.AVI. You can select another
drive for capturing. Occasionally, VidCon32 may terminate with a General Protection Fault (GPF).
Restart VidCon32, ignore the error message that the device is already active, and set the desired
drive for capturing. Close VidCon32 now and restart Windows 95.
Now start VidCon32 and open the menu items "Capture" and "Video".
A window with the title "Capture Video Sequence "opens. Now click the
"Video" button to check the video format and/or the data rate selected.
No matter what, avoid clicking the "OK" button in the "Video Capture
Sequence" window as long as the video format dialog box is still open. This
leads to a General Protection Fault in the module User.exe
3.60 Capturing single-frames
When capturing single-frames, please make sure that the "24 BIT RGB" format
(Vidcap//Options//Video Format) has been selected.
This format is compatible with all common graphics programs (also Kai┤s Power Goo).
Note: Vidcap does not specify a filename extension. (You should enter, for example, [Name].BMP.)
3.70 miroMEDIA AV-Control
This application is miroTELEVISION without video playback.
This makes it possible for you to control the audio and video parts of the
miroMEDIA PCTV (pro) even when using programs such as VidCon32,
Premiere or other capture programs.
3.80 miraser
Use this tool to remove the miroMEDIA PCTV (pro) entries from the Windows Registry.
Video conferencing systems consist of various (sub)systems.
The minimum configuration for video conferencing is as follows:
Video source: e.g., video camera
Capture board that supports the standard capture formats,
e.g., miroMEDIA PCTV
Sound card
Means of communication, e.g.: analog modem, ISDN modem, network
Video conferencing software, e.g., CU-SeeMe, VDO-Videophone, Microsoft Netmeeting,
just to mention a few.
The interaction of these components is standardized (H.324).
Optimum transmission speed and quality can be expected, provided all
the individual components comply with this standard.
Please note that, as a rule, the software packages are not (yet) mutually compatible.
5.10 H.324
The H.324 standard specifies the methods by which video, speech, and data are
transmitted together via a high-speed modem connection.
5.20 How does H.324 work?
H.324 is based on a standard - 28.8kb - modem connection. Once the connection
has been made, H.324 defines how the data is converted into digital signals and
compressed.
With a 28,800 bps connection, speech is compressed to 6.000 bps.
The remaining bandwidth is allocated to video data, which is also compressed.
5.30 What types of products support H.324?
1) Stand-alone videophones
- Installation and operation comparable to a "normal" telephone
- additional LCD display
2) TV-based videophone
- looks like a cable box with an integral video camera
- placed on top of the television set
- picture is displayed on the television set
- Connects to a normal telephone line
3) PC-based solution: videophone, video conferencing
- Display via PC monitor
- Communication via analog modem (>28,800 bps)
- Software application
- Intel Pentium performance is utilized for compression and decompression
5.40 What kind of quality can I expect?
Although the quality of the video solutions is improving continually, the
results obtained are still not TV-quality. Using a resolution of 192x144
pixels on both ends of the connection, the maximum rate attainable is 15 frames per second.
The result depends heavily on the relative motion of the object pictured. The sound is transmitted in standard telephone quality.
See also "Data transfer rates supported"
5.50 Can I use any modem?
To use H.324, the modem must support V.80. This standard is not (yet)
supported by the broad base of installed modems. Please contact the manufacturer
of your modem regarding the possibility of an update to V.80.
See also "Data transfer rates supported"
5.50 "Data transfer rates supported"
Frame Rate : 4 - 8 fps with a 28.8 Kbps Internet connection
Frame Rate : 8 -15 fps with a 128 Kbps Internet connection
Frame Rate : 5 - 15 fps with a H.324 Kbps direct connection
5.60 H.324 glossary
BPS Bits per second
G.723 Speech compression algorithm implemented in H.324
H.223 Multiplex control protocol used in H.324
H.245 Multiplex control protocol used in H.324
H.263 Video compression algorithm implemented in H.324
H.324 Communications standard for simultaneous transmission of video,
speech, and data via an analog modem connection
V.34 Industry standard for 28.800 bps analog modems
V.8 bis Describes products with Voice-Call-First capability
V.80 International Standard for V.34 modems "Videophone ready"
Voice-Call-First is the easiest way to establish a connection with a picture phone
videophone solution. The objective is to make using a videophone
like using a "normal" telephone, with the exception that there is an
additional button for additional video transmission.
6.00 Videotext
Videotext, which is also called teletext, is a text-based communication
method.
The data is transmitted in the unused lines of the television picture.
Main features
- 8 magazines per 100 pages
- Sub addressing, i.e., multiple pages
- Page format 24 lines containing 40 characters each
- Text displayed in 7 colors. Character background color may be one of 8 colors
- additional display possibilities
- Teletext pages are transmitted at a rate of approx. 8 pages/s
6.10 TOP
Table Of Pages
This is a service, provided to teletext users by the broadcasting networks,
that permits user-friendly retrieval of pages from the videotext cycle.
This ensures fast orientation in the teletext program offered and efficient
user prompting.
This service is optional, however.
The basic principle is that of transmitting a table, as a normal teletext page, on which all of the pages of the videotext program currently being broadcast are marked.
This often includes a link to the next page or the previous page, as well as the next
"card-index box" (e.g., news, sports...) and the next "groups" (e.g., sports: soccer, tennis,...).
6.20 FLOF
Full Level One Features
Various links are defined from each page to additional pages so that this page can be selected quickly.
In teletext, a FLOF page can be recognized by the four-color bar on the bottom edge of the page.
6.30 VPS
Video Programming System
Used to program VCRs for unattended recording; conveys station names.
6.40 WSS
Wide Signal Scaling
WSS is a process for distinguishing certain transmission attributes
(dolby surround sound, PAL plus,...) so that the decoder can adjust accordingly.
6.50 Hidden Text
On some pages, e.g., ones containing a riddle, . the answer is hidden when the page is first started. A special function can be used to make this text visible.
