The clipmirror class furnishes controls to activate and manipulate clip cache mirror operation and execution. The clipmirror subsystem furnishes a redundant storage mechanism for clip content.
The filesystem class furnishes controls to activate and manipulate the persistent clip storage mechanism, an integral element of MSB infrastructure. The filesystem enables real-time playout, record, edit, and ftp transfer of clip content.
The device class furnishes controls to configure and manipulate video codec operation. The video codec processes video and audio signals, generating clip content during playout, or capturing the real-time feed during record and transforming into digital persistent storage.
NOTE: There are many controls to govern MSB execution behavior. Appropriate SGET queries will reveal their names and current values; SSET can be used without constraint to modify them. However, unexpected and potentially catastrophic MSB behavior may arise if <B>controls <B>are <B>set <B>which <B>are <B>not <B>explicitly <B>documented in this page. Further, the control values assigned by either the initialization file, or via the MVCP SSET are not subject to rigorous range checking or verification. MSB will not honor an invalid input control value, and <I>may arbitrarily and silently assign a suitable default. Control value range checking is not rigorously performed in general.
A system-defaults file resides in /usr/vtr/config/system-defaults and is named according to the name of the subsystem.
The following subsystems and controls are currently supported:
Specifies the primary MSB server clip cache to mirror. Setting this value activates clip mirror processing. Setting this value to ``'' disables clip mirror processing. This control value must be set on the clip mirror platform.
Specifies the number of concurrent ftp transfers supported by the clip mirror platform. This value should consider available network bandwidth between the primary MSB server and mirror platforms. The permissible range for this control is 1 to 100. This control value must be set on the clip mirror platform.
Specifies how often (in seconds) the clip mirror platform attempts to reconnect with the primary MSB server if the connection terminates. This control value must be set on the clip mirror platform.
Contains the named identity of the primary MSB network interface dedicated for file transfer. Set on the primary MSB platform. Setting this value causes clip mirror transfers from the primary MSB server to the clip mirror to occur via the named interface. For example, if the primary MSB server possesses two network interfaces, one of them might be a 100BaseT ethernet (and known by the name vst1-enet) and the other might be a FibreChannel connection (and known by the name vst1-fc). If the default hostname is vst1-enet but vst1-fc is a higher bandwidth connection, then clip transfer can be assigned to vst1-fc.
Enables or disables use of Guaranteed Rate I/O (GRIO) rate guarantees for
file system copy operations. If this control is set to true then any file
that is copied to or from the real-time file system(s) under
the mount point /usr/vtr/clips will use a GRIO reservation. If this control
is set to true then the controls:
vtr.storage.fs.grio.bandwidth.copy.perstream vtr.storage.fs.grio.bandwidth.copy.total
need to be set in accordance with the instructions for these controls. This control enables bandwidth management for MVCP commands CCP, CBLD as well as for other control protocols.
Sets the total bandwidth that can be used for copy operations for each file system mounted under /usr/vtr/clips. Once set then any copy operation that exceeds the total copy bandwidth will fail. This control can be used to limit the total number of copy operations so that system resources remain available for video play and record functions. This setting should be set at a fraction of the total bandwidth available to the individual file systems. This setting does not control bandwidth allocated to ftp sessions.
Sets the bandwidth that can be used for copy operations for each file. This setting is set to a fractional value of the total bandwidth available for copy operations. If a copy is made within the clip cache then two reservations will be made. One reservation for the read operation and one reservation for the write operation. If any reservation exceeds the total bandwidth available for copy operations then the copy will fail.
Specifies the threshold (in milliseconds) which if exceeded by a single I/O operation during playback or recording will log a warning message.
Specifies the maximum number of bandwidth reservations allowed per real-time file system for cueing clips for playback. A cueing reservation allocates one I/O operation per second. If more units are cueing than the limit specified by this control, the units share the reservation round-robin.
Specifies the maximum log level of messages sent to stdout.
Specifies the maximum log level of messages sent to the server log file (usually, /usr/vtr/adm/logs/vtrlog).
Specifies the maximum log level of messages sent to the system log (usually /var/adm/SYSLOG).
Specifies the default timing standard for the system. Certain subsystems and devices use this value for determining the system timing standard. For example, MVCP initializes the control frame rate (FRAT command) using the value of this control. The initial output timing of the MFCODEC device is set based upon this control if the device timing control is set to ``system''.
This default is also used in certain situations when there is ambiguity about the timing standard in use. For example, certain DVCPRO DIF files may not have the timing standard information available in the headers. This control may be set to either ``525'' or ``625'' to select the default behavior.
Specifies whether the system time (maintained by IRIX) is slaved to the timecode inputs for this time channel. Only one channel can be used to slave the system time.
Depending on the stability of the incoming timecode signal, the IRIX system time usually tracks within 500us of the input timecode.
Specifies the offset (in nanoseconds) between the actual timebase and the decoded input timecode. This offset accounts for delays in the timecode reader, in the serial communications with VST, and in the VST time processing.
A device-defaults file resides in /usr/vtr/config/device-defaults. Device-defaults files are loaded according to a hierarchical scheme enabling common control settings to be shared among devices.
When a unit device interface is initialized, control settings are loaded from device-defaults files in the following order:
Settings for all devices: ALL Settings for node type: MEDIA Settings for port type: VIDEO, DECK Settings for device class: <device-class> Settings for device: <device-name> For example, when the unit device interface for the MFCODEC_1 video device is initialized, settings are loaded from the device-defaults files as follows:
ALL MEDIA VIDEO MFCODEC MFCODEC_1
The following device controls are currently supported:
This read-only control returns the last error detected from the deck control interface.
This read-only control returns the current deck transport status.
Specifies how far in advance of the edit in-point that VST attempts to sync. Under some circumstances, the actual coincidence point will be a few frames later than specified, so this control should be set to at least 10 frames.
Specifies the deck preroll for edit operations.
Specifies the deck postroll for edit operations.
This read-only control returns the current status of an edit operation that is in-progress.
This read-only control returns the video frame rate currently being reported by the deck.
Specifies the port number from which the deck control interface should derive video sync timing. This should be set to the port that will be used for capturing from or laying-down to the deck.
If the control is not set, VST will use any available port which has active video, but a warning will be issued.
Specifies the number of fields to be used as the video sync offset when capturing from the deck. If captures from the deck start and end too late, a negative offset can be used to move the synchronization earlier. If the captures start and end too early, a positive offset should be used.
Specifies the number of fields to be used as the video sync offset when laying-down to the deck. If lay-downs to the deck start and end too late, a negative offset can be used to move the synchronization earlier. If the lay-downs start and end too early, a positive offset should be used.
Specifies the current output mode of the deck. The value may be ``pb'' for normal playback or ``ee'' for E-to-E.
Specifies that frames are automatically cleared from the clip after being played. The clip must be loaded for input/output.
This mechanism is used to implement a delay. One unit records the clip while another unit plays the same clip delayed by some fixed interval. Setting the clear_after_play control releases the disk space occupied by the frames after they have been played; hence, the disk utilization remains constant.
This control takes effect immediately.
Specifies that the unit continues playing after an I/O error occurs. Any frames that could not be read from the clip file will be played as black.
Specifies the log level for I/O logging messages.
Specifies the maximum number of clip files that the unit may have open at a single time. If the unit is playing a segmented clip with a large number of short source clips, the source clips will be opened and closed as needed to stay within the specified limit.
Specifies the maximum allowable interframe gap (the distance between the ending of one frame and the beginning of another). If the interframe gap is less than the value of this control, vst will perform an extent size io read instead of a single frame io read.
Specifies which audio input source is used for each audio channel pairs in recording. 'E' for embedded, 'D' for AES/EBU, 'A' for analog input.
If recording is in-progress when this control is changed, the input audio device will not be reconfigured until recording is stopped and restarted.
Specifies audio input channel pairs in the order to be recorded in the clip. For example, a setting of ``1111'' will record the first pair to all the audio channels in the clip.
If recording is in-progress when this control is changed, the input audio device will not be reconfigured until recording is stopped and restarted.
Specifies the number of audio input channels to be read from the audio device. This can be fewer than the number of channels supported by the audio device but cannot be greater. Currently, the supported values are 1, 2, and 4.
If recording is in-progress when this control is changed, the input audio device will not be reconfigured until recording is stopped and restarted.
Specifies the gain for the analog input during recording. The value supplied must be between 0 and 100. This control takes effect immediately.
Specifies the audio channel pair to be played out on the analog output (a value between 1 and 4). A value of 13 causes LTC output to be inserted on analog output.
If playback is in-progress when this control is changed, the output audio device will not be reconfigured until recording is stopped and restarted.
Specifies the volume for the analog output during playback. The value supplied must be between 0 and 100. This control takes effect immediately.
Specifies the maximum number of audio channels to embed in the outgoing SDI video signal (value can be either 4 or 8).
Specifies the number of video fields to offset the start of audio playback. This value should be 0 for MPEG and -1 for DVCPRO.
Enables constant bit rate encoding. If set to false, variable bit rate will be used.
If recording is in-progress when this control is changed, the setting will not be changed until recording is stopped and restarted.
No other input format is currently supported.
Specifies the input field dominance. Possible values are F1 and F2.
This control is only read when a new clip is being created. Changing this control will not affect any existing clips including the one currently loaded.
Setting this control will reset the video device. All recording in progress on this device will be stopped. This control should only be used as a last resort in error recovery.
Specifics the horizontal resolution of the video signal to be captured. '720' is the only supported value in this release.
Enables encoding of the entire video signal, including the vertical blanking interval. When set to ``true'', in NTSC, 512 lines of video signal is captured; and in PAL, 608 lines of video signal is captured. When set to ``false'', in NTSC, only 408 lines of video signal is captured; and in PAL, 576 lines of video signal is captured.
If recording is in-progress when this control is changed, the setting will not be changed until recording is stopped and restarted.
Specifies the video line where vitc (vertical interval time code) data is present in the video signal. The default is line 14 and 16.
If recording is in-progress when this control is changed, the setting will not be changed until recording is stopped and restarted.
Specifies the video line where vitc (vertical interval time code) data is inserted in the video signal. The default is line 14 and 16.
If playback is in-progress when this control is changed, the setting will not be changed until playback is stopped and restarted.
Setting this control will reset the video device. All play out in progress on this device will be stopped. This control should only be used as a last resort in error recovery.
Specifies the name of the image displayed when the unit output mode is ``image'' and the vtr.media.output.image.type is ``user''. The image must be placed in the appropriate directories under /usr/vtr/data/images.
Specifies the image displayed when the unit output mode is ``image''. The possible values are:
smpte-75-bars 75% saturation SMPTE color bars with PLUGE 75-bars-over-red 75% saturation color bars over red bars smpte-75-bars (525), 75-bars-over-red (625) black Black user User (vtr.media.video.output.image.name)
Setting this control effects how media MSB jogs (for example single steps) through video. The choices are:
false Jog in frames, displaying the top field. true Jog in fields.
Specifies the unit's output mode when it is cued. The possible values are:
clip Normal clip video/audio output hold Keep frame from last played clip black Black (silent audio) image Still image (vtr.media.video.output.image.type)
Specifies the unit's behavior when a ``GOTO timecode'' is handled. The possible values are:
clipOnly Accept timecode within the clip; ignore timecode
outside of the clip start/end boundaries and issue
an error message in the logfile
inoutOnly Only accept timecode within hard/soft IN/OUT points
of the clip if these exist; ignore the timecode if it
is outside of the hard/soft IN/OUT point and issue an
error message in the logfile
inoutClamp Accept timecode within the clip; if the timecode is
within the clip start/end boundaries but outside of
hard/soft IN/OUT points, clamp it to IN/OUT points;
issue an error message in the logfile if the timecode
is outside of the clip start/end boundaries
Specifies the type of trigger used to begin recording. The default value, ``none'', disables triggering; recording begins immediately (subject to command scheduling if the record command is time-stamped).
The value ``vitc'' enables VITC-triggering. When the unit record command is received, the unit begins monitoring the VITC of each input frame. When an input frame whose VITC matches the value of vtr.media.input.trigger.vitc.in is received, recording begins. The triggering frame is the first frame recorded to the clip.
The value ``ltc'' enables LTC-triggering. When the unit record command is received, the unit begins monitoring the LTC of each input frame. When an input frame whose LTC matches the value of vtr.media.input.trigger.ltc.in is received, recording begins. The triggering frame is the first frame recorded to the clip. LTC input is expected to be on the analog audio input jack.
This control is only read once before the recording is started.
Specifies the type of trigger used to end recording. The default value, ``none'', disables triggering; recording ends immediately after the unit receives a stop command (subject to command scheduling if the record command is time-stamped).
The value ``vitc'' enables VITC-triggering. When recording begins, the unit begins monitoring the VITC of each input frame as it is recorded. When an input frame whose VITC matches the value of vtr.media.input.trigger.vitc.out is received, recording ends.
The value ``ltc'' enables LTC-triggering. When recording begins, the unit begins monitoring the VITC of each input frame as it is recorded. When an input frame whose LTC matches the value of vtr.media.input.trigger.ltc.out is received, recording ends. LTC input is expected to be on the analog audio input jack.
This control is only read once before the recording is started.
Specifies the VITC of the first frame recorded when the input trigger-in mode is VITC.
This control is only read once before the recording is started.
Specifies the VITC of the frame following the last frame recorded when the input trigger-out mode is VITC.
Specifies the LTC of the first frame recorded when the input trigger-in mode is LTC.
This control is only read once before the recording is started.
Specifies the LTC of the frame following the last frame recorded when the input trigger-out mode is LTC.
This control is only read once before the recording is started.
Specifies the timecode to be stored in each DIF frame during DVCPRO capture. When a DVCPRO clip is played back, this time code is outputted when the vitc or ltc output mode is set to ``source'' (see vtr.media.video.output.vitc.mode). The possible values are:
off Zeroed source VITC timecode clip Clip location (CTL) timecode vitc VITC timecode ltc LTC timecode freerun Value of free-running counter run Value of running counter date Current date time Current time constant Constant value
The free-running counter begins incrementing immediately from the value set into vtr.media.input.timecode.preset and continues running regardless of whether the unit is recording or idle.
The running counter increments from the value set into vtr.media.input.timecode.preset, but only when the unit is actively recording.
The constant value is also determined by the timecode preset value.
This control takes effect immediately.
Specifies the initial value of the free-running counter which is used by vtr.media.input.timecode.mode in freerun, run and constant modes. The value must be a valid timecode.
This control takes effect immediately.
Specifies the userbits to be stored in each DIF frame during DVCPRO capture. When a DVCPRO clip is played back, these userbits are outputted when the userbit output mode is set to ``source'' (see vtr.media.video.output.vitc.userbits.mode). The possible values are:
off Zeroed source VITC userbits clip Clip location (CTL) timecode vitc VITC userbits ltc LTC userbits freerun Value of free-running counter run Value of running counter date Current date time Current time constant vtr.media.input.userbits.constant
The free-running counter begins incrementing immediately from the value set into vtr.media.input.userbits.preset and continues running regardless of whether the unit is recording or idle.
The running counter increments from the value set into vtr.media.input.userbits.preset, but only when the unit is actively recording.
For both the running and free-running counter, the preset value used must be a valid time code. To insert an arbitrary constant into the userbits use the choice ``constant'' and load the value with vtr.media.input.userbits.constant.
This control takes effect immediately.
Specifies the initial value of the free-running counter which is used by vtr.media.input.userbits.mode in freerun and run modes. The value must be a valid timecode.
This control takes effect immediately.
Specifies an arbitrary constant for insertion into the userbits of each DIF frame during DVCPRO capture. This constant should be in hex format, for example, 0xaabbccdd. This constant is selected by the setting the control vtr.media.input.userbits.mode to ``constant''.
This control takes effect immediately.
Specifies the timecode of the first frame recorded into an empty clip if no timecode is specified when the unit is cued for recording and the vtr.media.clip.start.mode is set to ``preset''.
This control is only read when a newly created clip is cued for recording and no in-point has been specified for cueing.
Specifies the mode for determining the timecode of the first frame recorded into an empty clip if no timecode is specified when the unit is cued for recording. A value of ``preset'' specifies that the timecode is taken from vtr.media.clip.start.preset. A value of ``time-of-day'' specifies that the timecode is taken from the current time-of-day when the first frame comes into the system. A value of ``vitc'' specifies that the timecode is taken from the VITC embedded in the first frame. A value of ``ltc'' specifies that the timecode is taken from the LTC corresponding to the first frame.
This control is only read when a newly created clip is cued for recording and no in-point has been specified for cueing.
Specifies the preroll used when vtr.media.clip.start.mode is set to ``ltc''. This control pertains only to mpeg capture and should be changed with great care.
Specifies the preroll used when vtr.media.clip.start.mode is set to ``vitc''. This control pertains only to mpeg capture and should be changed with great care.
Specifies the bit rate used in encoding video. If vtr.media.video.input.constant_bit_rate is set to false, this will be the maximum bit rate used.
If recording is in-progress when this control is changed, the setting will not be changed until recording is stopped and restarted.
Specifies whether the device should be configure as an output port or an input port. Valid settings are ``output'' and ``input''.
If a play or record is in-progress when this control is changed, the setting will not be changed. Changing this setting will cause a reload of system firmware. /SYNC should be used to ensure that the system has finished reloading the new firmware.
Specifies the type of compression applied to video frames being recorded.
The possible values are:
mpeg2 MPEG2 encoding dvcpro DVCPRO-25 encoding dvcpro50 DVCPRO-50 encoding
If recording is in-progress when this control is changed, the setting will not be changed. Changing this setting will cause a reload of system firmware. /SYNC should be used to ensure that the system has finished reloading the new firmware.
Specifies the sampling rate used in encoding the video signal. Valid values are ``422'' and ``420''. This control only has an effect when compression type is set to ``mpeg2''.
If recording is in-progress when this control is changed, the setting will not be changed. Changing this setting will cause a reload of system firmware. /SYNC should be used to ensure that the system has finished reloading the new firmware.
Note: 420 compression sampling is limited to 15Mbit/sec bit rate by the PCI-VIDAUD-MSB hardware. The vtr.media.mpeg.bit_rate values exceeding this limit are ignored under 420 compression sampling. 420 compression may generate large block-pixel images, depending on the ingested content scene change rate.
Specifies the gop structure for encoding when the compression type is set to ``mpeg2''. The gop structure determines the type and pattern of MPEG frames (I, P, or B) that are used within a GOP.
The possible values are:
I GOP period = 1 IP GOP period = 1 IPB GOP period = 2 IPBB GOP period = 3
The GOP period of a structure must evenly divide the GOP size (see below). ``IPBB'' encoding is only available when the compression sampling is set to ``420''.
Specifies the size of the GOP that is used when encoding video. The gop size must be a multiple of the the gop period (as implied by the control vtr.media.video.input.compression.gop_structure. The GOP size must be between 1 and 15 (inclusive). For a given gop size and period some sample GOPS would be:
size, period Stored GOP
------------ ---------------
1,1 I
15,1 IPPPPPPPPPPPPPP
6,3 IBBPBB
15,3 IBBPBBPBBPBBPBB
Specifies the video timing used by a port. This is actually a global control which determines the video timing used by a port in either input or output mode (i.e. it specifies the video timing for both record and playback). ``29.97'' denotes NTSC. ``25'' denotes PAL.
Changing this setting will cause a reload of system firmware. /SYNC should be used to ensure that the system has finished reloading the new firmware.
Specifies the back panel is installed. If dangle is used for audio input and/or output, vtr.media.audio.output.backpanel should be set to false.
Specifies the data sent for the VITC time code of each frame. The possible values are:
off Zeroed source VITC from recorded clip clip Clip location (CTL) timecode vitc VITC from recorded clip ltc LTC from recorded clip freerun Value of free-running counter run Value of running counter date Current date time Current time constant Constant value
The free-running counter begins incrementing immediately from the value set into vtr.media.video.output.vitc.timecode.preset and continues running regardless of whether the unit is playing or idle.
The running counter increments from the value set into vtr.media.video.output.vitc.timecode.preset, but only when the unit is actively playing.
The constant value is also determined by the vitc timecode preset value. This control takes effect immediately.
Specifies the initial value of the free-running counter which is used by the VITC time code insertion in freerun, run and constant modes.
This control takes effect immediately.
Specifies the data sent in the VITC user bits of each frame. The possible values are:
off Zeroed source VITC userbits from recorded clip clip Clip location (CTL) timecode vitc VITC userbits ltc LTC userbits freerun Value of free-running counter run Value of running counter date Current date time Current (local) time constant vtr.media.video.output.vitc.userbits.constant
The free-running counter begins incrementing immediately from the value set into vtr.media.video.output.vitc.userbits.preset and continues running regardless of whether the unit is playing or idle.
The running counter increments from the value set into vtr.media.video.output.vitc.userbits.preset, but only when the unit is actively playing.
For both the running and free-running counter, the preset value used must be a valid time code. To insert an arbitrary constant into the user bits use the value ``constant'' and enter the desired constant with vtr.media.video.output.vitc.userbits.constant.
This control takes effect immediately.
Specifies the initial value of the free-running counter which is used for VITC user bit insertion in freerun and run modes. Must be a valid timecode.
This control takes effect immediately.
Specifies an arbitrary constant for insertion into the vitc userbits. This constant should be in hex format, for example, 0xaabbccdd. To use this constant, a value of ``constant'' must be specified for vtr.media.video.output.vitc.userbits.mode.
This control takes effect immediately.
Specifies the data sent for the LTC time code of each frame. The possible values are:
off Zeroed source LTC from recorded clip clip Clip location (CTL) timecode vitc VITC from recorded clip ltc LTC from recorded clip freerun Value of free-running counter run Value of running counter date Current date time Current time constant Constant value
The free-running counter begins incrementing immediately from the value set into vtr.media.video.output.ltc.timecode.preset and continues running regardless of whether the unit is playing or idle.
The running counter increments from the value set into vtr.media.video.output.ltc.timecode.preset, but only when the unit is actively playing.
The constant value is also determined by the ltc timecode preset value.
This control takes effect immediately.
Specifies the initial value of the free-running counter which is used by the LTC time code insertion in freerun, run, and constant modes.
This control takes effect immediately.
Specifies the data sent in the LTC user bits of each frame. The possible values are:
off Zeroed source LTC userbits from recorded clip clip Clip location (CTL) timecode vitc VITC userbits ltc LTC userbits freerun Value of free-running counter run Value of running counter date Current date time Current (local) time constant vtr.media.video.output.ltc.userbits.constant
The free-running counter begins incrementing immediately from the value set into vtr.media.video.output.ltc.userbits.preset and continues running regardless of whether the unit is playing or idle.
The running counter increments from the value set into vtr.media.video.output.ltc.userbits.preset, but only when the unit is actively playing.
For both the running and free-running counter, the preset value used must be a valid time code. To insert an arbitrary constant into the user bits use the value ``constant'' and then enter the desired constant with vtr.media.video.output.ltc.userbits.constant.
This control takes effect immediately.
Specifies the initial value of the free-running counter which is used for LTC user bit insertion in freerun and run modes.
This control takes effect immediately.
Specifies an arbitrary constant for insertion into the ltc userbits. This constant should be in hex format, for example, 0xaabbccdd. This constant is selected by setting the control vtr.media.video.output.ltc.userbits.mode to ``constant''.
Specifies the horizontal offset (in half pixels) applied to the output video relative to the incoming sync reference. This control is only meaningful if the output video is properly synchronized to an external reference (genlocked).
For example, to offset the output video 20 pixels from the the incoming reference input, a value of 40 would be required. There is no visible shift in the outputted video because it is inserted in the correct active portions of the offset timing. The shift adjustment can be used for SDI video by applications that want the SDI output video to have a timing similar to a house sync. Only positive values are allowed.
For PAL there are 1728 half pixels per video line and the offset is measured relative to the current pixel. Therefore a value of 1727 wraps around the line and shifts the offset back a half pixel. A value of 1726 shifts the offset back a full pixel. Values bigger than 1727 are allowed, they simply wrap around the line.
For NTSC there are 1716 half pixels per video line and the offset is measured relative to the current pixel. Therefore a value of 1715 wraps around the line and shifts the offset back a half pixel. A value of 1714 shifts the offset back a full pixel. Values bigger than 1715 are allowed, they simply wrap around the line.
This control takes effect immediately.
Specifies the vertical offset (in lines) applied to the output video relative to the incoming sync reference. This control is only meaningful if the output video is properly synchronized to an external reference.
Only positive values are accepted. Meaningful ranges are from 0 to 524 for NTSC and from 0 to 624 for PAL. The offset is measured relative to the current line and wraps around the video frame. A value of 524 in NTSC or 624 in PAL shifts the offset backwards one line. Values bigger than 524/624 are allowed, they simply wrap around the video frame.
This control takes effect immediately.
Specifies the type of compressed media that is initially played through an output port.
The possible values are:
mpeg2 MPEG2 encoding dvcpro DVCPRO-25 encoding dvcpro50 DVCPRO-50 encoding
MPEG2 uses different video settings then the two DVCPRO formats. This means that the hardware must be initialized differently for MPEG2 then for DVCPRO-25/50. As a result, MPEG2 clips cannot be played back-to-back with DVCPRO-25/50 clips using the same port. However, if an output port is not playing then MSB does support switching to a clip of a different format (i.e. switching between MPEG2 and DVCPRO-25/50). This control allows the user to specify the default behaviour of MSB - whether it is initialized to start playing MPEG2 or DVCPRO-25/50 clips.