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Chapter 2 — Overview and Operation
NOTES: (1) The Pause command cannot be sent within the first second of playback.
(2) Once the decoder has been Paused, additional MPEG data (via the write 10 com-
mand) should not be sent. If all the MPEG buffers become full while in Pause, the next
write 10 will never complete. This usually results in a SCSI command timeout from the
host adapter (initiator) which causes a Bus Reset. If more MPEG data is sent, the
application must check Mode Page 30h (via mode sense command) to be sure there is
sufficient room in the MPEG buffers (bytes 14 and 15). When Frame Advance is used,
the decoder will require additional MPEG data when advancing many frames.
0010 Freeze Frame: Freezes the video image, but the decode continues in the
background. Use Resume command 0012h to resume playback.
0011 Flush Channel Buffer: Stops playback after all data in the decoder's buff-
ers is used. Equivalent to
0012 Resume Play (from Pause): Resumes playback after a pause.
0013 Mute Audio: Mutes the audio output.
0014 Unmute Audio: Unmutes audio output. Disabled during Fast Forward,
Slow Motion, Pause, and Freeze Frame.
0015 Set Stand-Alone Mode (Genlock Disable): Default mode of the decoder.
0016 Set Genlock Mode: This enables the decoder to synchronize to the gen-
lock input source.
• Bit 8 of the command is reserved.
• Bit 9 of the command allows for automatic switching to Standalone
mode upon detection of loss of genlock.
• Bits 10-11 is genlock source selection.
• Bits 12-15 of the command is reserved.
Bit 9
0
1
This feature requires that Error Reporting be enabled, i.e., decoder (45h) com-
mand, command code 002Bh, with bit 10 set to 1 to enable Genlock Loss
reporting. When genlock input is not detected during playback, the decoder
will switch back to Standalone mode and return the following error:
Recovered
RESET BUFFER
Loss of Genlock, switch back to Standalone
Feature disabled (default)
Enables feature. When the decoder detects a loss of genlock,
the decoder will automatically switch back to standalone mode.
(0021h).
DECODER Command (45h)
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