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The FullVideo Supreme option module does not deal with state
information through the
ICGetState
and
ICSetState
functions. It does not store or make available any state information
but always returns zero bytes for both get and set operations.
B.2.5 FullVideo Supreme Video Field Mode Support
The video interfaces videoGetFieldMode and videoSetFieldMode provide better control over frame and field modes, and in field mode, identify which field is the target of operation. The FullVideo Supreme option module supports the following modes:
| Mode | NTSC | PAL/SECAM |
|---|---|---|
| FRAME | Yes | No |
| EVEN_ONLY | Yes | Yes |
| ODD_ONLY | No | No |
| BOTH | Yes | Yes |
If alternate odd and even fields are captured in a dithered format, the quality of the resulting frame will not be as good as the quality from a captured frame. Dithered images captured from the FullVideo Supreme option modules in even and odd field modes will look grainy. It is possible to capture the images in YUV format and then dither them by calling the ICDecompress function to convert the YUV format to dithered format. |
Revision B of the FullVideo Supreme option module allows adjustment of video capture field dominance. By default, this option module uses odd dominance for video capture. It uses odd dominance for video playback, but the dominance cannot be adjusted.
The FullVideo Supreme option module that supports this can be determined by examining the part number on the module itself:
Revision A 54-23296-04.A01
Revision B 54-23296-04.B01
This section describes the volume settings for the Microsoft Sound
Board driver and for the Compaq Ensoniq AudioPCI device.
B.3.1 Microsoft Sound Board Driver Volume Settings
The Microsoft Sound Board driver provides 6 bits of volume levels on the output side, and either 4 or 5 bits of volume levels are provided on the input side. The high-order bits passed to the waveInSetVolume and waveOutSetVolume functions are selected; low-order bits are ignored.
For output volumes, these bits are converted into 64 different dB attenuation levels (--94.5 to 0.0, in 1.5 dB steps). For input volumes, 5 bits are used for the microphone input port, and 4 bits are used for all other input ports. For the microphone input port volume, the high-order bit is used to select a +20.0 dB gain that will be applied to the microphone input port only, and the next 4 bits select one of 16 dB gain levels (0.0 to +22.5, in 1.5 dB steps). For all other input ports, the high-order 4 bits are used to select one of 16 dB gain levels (0.0 to +22.5, in 1.5 dB steps).
One of three audio CODEC chips can be used on the Microsoft Sound Board (MSB) and MSB-compatible sound boards: Analog Devices (AD) 1848 J-grade, AD1848 K-grade, or the Crystal Semiconductor 4248. With the AD1848 K-grade CODEC chip, a click may be heard when opening the Microsoft Sound Board (MSB) device. This is a characteristic of the AD1848 K-grade chip and cannot be corrected with software. The sound cards shipped with the AlphaStation 200 and AlphaStation 250 systems contain this chip. CODEC chips used on MSB-compatible boards that do not have this characteristic are the AD1848 J-grade and the Crystal chip. An audio CODEC chip is square, approximately 24 millimeters long on each side, and has 68 pins. The type of chip used on a sound card can be identified as follows:
|
You may experience a problem with noise on the MSB and other systems
using Microsoft window sound systems when a microphone is plugged in.
An MSB card using an AD1848 K-grade chip that has a microphone
connected passes audio from the microphone to the audio output, but the
audio can be distorted. This can happen with the machine in any state,
as long as it is powered on. On the AlphaStation 200 and AlphaStation
250 systems with the internal speaker connected, the distorted sound
will come through the speaker.
B.3.2 Compaq Ensoniq AudioPCI Audio Device
This section describes the Compaq Ensoniq AudioPCI device in terms of the following:
The Compaq Ensoniq AudioPCI device is based upon two chips, the Ensoniq ES1373 chip, and an industry standard Audio Codec 97 [AC97] Version 2.1 chip. Note that Ensoniq has been bought by Creative Labs. The ES1373 chip is not compatible with, or related to, the ESS technology ES1888 chip used in the Compaq Personal Workstation AU series. Information on the AC97 Codec Standard is available on the World Wide Web, at the Intel web site.
The ES1373 processes all audio in the digital realm; the AC97 processes all audio in the analog realm. Audio data originating from digitally stored data (wave files) passes through the computer bus to the ES1373 chip, is converted to 48K pcm data, and is then passed through an on-board 48K synchronous connection to the AC97. All device external inputs and outputs connect to the AC97. Digital data being recorded passes as 48K pcm data from the AC97 to the ES1373, is converted apropriately, and is then passed through the computer bus to main memory.
The AC97 Version 2.1 standard requires that each compliant AC97 Version 2.1 codec provides certain analog inputs and outputs, and leaves certain other inputs and outputs as optional. Depending upon the particular chip in use, the following inputs and outputs may or may not be available on a particular audio module.
Viewed at a high level, the AC97 implements the AC97 Mixer
functionality. The AC97 Mixer provides a number of stereo and mono
inputs (including PCM_out from the ES1373), and two primary stereo
outputs, LINE_OUT and PCM_IN. The path to LINE_OUT provides mutes and
gains on each signal, mixes all input signals, applies a final MASTER
VOLUME gain or mute, and then passes the signal to LINE_OUT. The path
to PCM_IN selects one of the inputs or the mixer output, applies a
MASTER INPUT VOLUME gain, and then passes the PCM_IN record signal to
the ES1373.
B.3.2.2 Compaq Ensoniq AudioPCI Module Inputs and Outputs
The following are the device module input and output ports:
Note that some Ensoniq AudioPCI module boards previously shipped by
Compaq, or shipped directly from Ensoniq or Creative Labs, may contain
more or less ports than listed above. The Compaq part number officially
supported is 159579.
B.3.2.3 Multimedia Services API Inputs and Outputs
The following sections describe the input and output ports selectable
through the Multimedia Services API.
B.3.2.3.1 Multimedia Services Input Ports
The following ports are available for recording. The current Ensoniq AudioPCI module does not provide connections for every port. Each port is listed with its Multimedia Services port identifier suffix, as listed in the mmsystem.h file.
The following port enables a certain component of the AC97 mixer:
The following additional ports enable or disable the AC97 Mixer inputs. When enabled, the gain volume is set to its default AC97 value. When disabled, the input is muted.
B.3.2.3.2 Multimedia Services Output Ports
Only one Multimedia Services output port is currently supported: Stereo
Line Out (LINE_OUT).
B.3.2.4 Compaq Ensoniq AudioPCI Volume Setting
On the output side, waveOutSetVolume controls the Master Volume setting, which is applied to the LINE_OUT signal just before it exits the AC97 Codec. On the input side, waveInSetVolume controls the Master Input Volume just before the signal is converted back to the digital domain, and passed back to the ES1373 chip.
The AC97 Codec provides 6-bits, or optionally 5-bits, of volume levels on the output side, and 4-bits of volume levels on the input side. The high order bits passed to waveInSetVolume and waveOutSetVolume are selected; low-order bits are ignored.
Multimedia Services provides no volume controls for the AC97 Mixer Input Ports. If the port is enabled, the gain setting is set to its AC97 Codec default value, which is usually 0db. If the port is disabled, the port is muted.
Multimedia Services treats the Microphone 20db gain as an input port.
If this port is enabled, then a 20db gain is applied to Microphone
signal prior to its being sent to the Record side, and prior to its
being sent to the AC97 Mixer (on the output side). If the port is
disabled, then no gain is applied (0db).
B.4 Software JPEG CODEC
This section describes the compressor and decompressor details for the
Software JPEG CODEC (Compressor and Decompressor).
B.4.1 Overview of Software JPEG CODEC Details
A Software JPEG CODEC is provided with Multimedia Services. Currently, the Software JPEG library is loaded on the client side of Multimedia Services (see Figure 1-1). Multiple clients can run simultaneously.
By default, the Software JPEG CODEC is available in the list of compressors and decompressors in the SYS$SYSTEM:SYSTEM.INI file. It is loaded into Multimedia Services for OpenVMS each time the Multimedia server is started.
To disable Software JPEG CODEC support in Multimedia Services, edit the SYS$SYSTEM:SYSTEM.INI file, and remove the following line:
vidc.sjpg=mmov$softjpeg |
This line is usually the last line in the
SYSTEM.INI
file. If Multimedia Services for OpenVMS is running, you must first
shut it down and restart it for this change to take effect.
B.4.2 Software JPEG CODEC JPEGINFOHEADER Data Structure Fields
The Software JPEG Compressor option supports compression to both the JPEG_DIB and MJPG_DIB formats. The Software JPEG Decompressor allows decompression of JPEG to X image 8 bit and 24 bit, and supports both JPEG_DIB and MJPG_DIB formats. Table B-9 lists the following variations.
| Field | Value |
|---|---|
| JPEGProcess | JPEG_PROCESS_BASELINE. |
| JPEGColorSpaceID | JPEG_Y, JPEG_YCbCr, and JPEG_RGB. |
| JPEGBitsPerSample | 8 |
| JPEGHSubSampling | 2. This value must be 1 for JPEG_Y. |
| JPEGVSubSampling | 1 |
| BICOMP_DECXIMAGEDIB | Supported for Software JPEG Decompressor. |
The following are restrictions associated with the Software JPEG CODEC:
The Software JPEG CODEC supports several video formats, as described in Table B_10 and Table B-11. The tables describe the compression, the bitcount, and the JPEG colorspace ID (for input and output) as used in the BITMAPINFOHEADER data structure.
Chapter 7 contains details of the fields in the BITMAPINFOHEADER data structure.
The following applies to Table B-10. For 32-bit BI_BITFIELDS formats, these formats only support 8-bit masks in RGB or BGR order with 8 bits of padding. |
| Input | Output | |||
| biCompression | biBit- Count |
biCompression | biBit- Count |
JPEGColorSpace |
|---|---|---|---|---|
| BICOMP_DECXIMAGEDIB | 24 | JPEG_DIB | 24 | JPEG_YCbCr |
| BI_BITFIELDS | 32 | JPEG_DIB | 24 | JPEG_YCbCr |
| BICOMP_DECYUVDIB | 16 | JPEG_DIB | 24 | JPEG_YCbCr |
| BICOMP_DECXIMAGEDIB | 24 | JPEG_DIB | 8 | JPEG_Y |
| BI_BITFIELDS | 32 | JPEG_DIB | 8 | JPEG_Y |
| BICOMP_DECYUVDIB | 16 | JPEG_DIB | 8 | JPEG_Y |
| BICOMP_DECXIMAGEDIB | 24 | MJPG_DIB | 24 | JPEG_YCbCr |
| BI_BITFIELDS | 32 | MJPG_DIB | 24 | JPEG_YCbCr |
| BICOMP_DECYUVDIB | 16 | MJPG_DIB | 24 | JPEG_YCbCr |
The following applies to Table B-11. For 32-bit BI_BITFIELDS input and output, these formats only support 8-bit masks in RGB or BGR order with 8 bits of padding. |
| Input | Output | |||
| biCompression | biBit- Count |
JPEGColorSpaceID | biCompression | biBit- Count |
|---|---|---|---|---|
| JPEG_DIB | 24 | JPEG_YCbCr | BICOMP_DECXIMAGEDIB | 8 |
| JPEG_DIB | 24 | JPEG_YCbCr | BICOMP_DECXIMAGEDIB | 24 |
| JPEG_DIB | 24 | JPEG_YCbCr | BICOMP_DECYUVDIB | 16 |
| JPEG_DIB | 24 | JPEG_YCbCr | BI_BITFIELDS | 32 |
| JPEG_DIB | 8 | JPEG_Y | BICOMP_DECXIMAGEDIB | 8 |
| JPEG_DIB | 8 | JPEG_Y | BICOMP_DECXIMAGEDIB | 24 |
| JPEG_DIB | 8 | JPEG_Y | BICOMP_DECYUVDIB | 16 |
| JPEG_DIB | 8 | JPEG_Y | BI_BITFIELDS | 32 |
| MJPG_DIB | 24 | JPEG_YCbCr | BICOMP_DECXIMAGEDIB | 8 |
| MJPG_DIB | 24 | JPEG_YCbCr | BICOMP_DECXIMAGEDIB | 24 |
| MJPG_DIB | 24 | JPEG_YCbCr | BICOMP_DECYUVDIB | 16 |
| MJPG_DIB | 24 | JPEG_YCbCr | BI_BITFIELDS | 32 |
| BICOMP_DECXIMAGEDIB | 24 | -- -- | BICOMP_DECXIMAGEDIB | 8 |
| BI_BITFIELDS | 32 | -- -- | BICOMP_DECXIMAGEDIB | 8 |
| BICOMP_DECYUVDIB | 16 | -- -- | BI_BITFIELDS | 32 |
| BICOMP_DECYUVDIB | 16 | -- -- | BICOMP_DECXIMAGEDIB | 24 |
| BICOMP_DECYUVDIB | 16 | -- -- | BICOMP_DECXIMAGEDIB | 8 |
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