Deck control (recorder)

A Recorder allows to control VTR decks using Sony RS-422 interface using Blackmagic Decklink cards.

To be able to record a clip from VTR, a input channel must be set up with Decklink input active. Following caspar.config entry is an example:

<channel>
  <video-mode>PAL</video-mode>
   <input>
      <decklink>
         <device>2</device>
         <timecode-source>sdi</timecode-source>
      </decklink>
   </input>
</channel>

Notice that this channel:

• has no consumer (however it may have some),
• has initially opened decklink as sole producer from device 2.
• the decklink producer captures timecode from SDI (RP188) that will be used to determine frames that should be recorded. Other options are serial and vitc.

A deck-control recorder should be set up in casparcg.config file as follows:

<recorders>
  <decklink>
    <device>2</device>
    <preroll>3</preroll>
    <offset>-3</offset>
  </decklink>
</recorders>

Device should be the same as input device, this setting determines decklink's RS-422 serial port to use.

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Recorder supports following commands:

CAPTURE [channel_index] RECORDER [recorder_index] {IN [timecode] OUT [timecode]} | {LIMIT [frame_count]} FILE [filename_with_extension] NARROW [TRUE|FALSE] {ACODEC [audio_codec] VCODEC [video_codec] ARATE [audio_bitrate] VRATE [video_bitrate] OPTIONS [options]}

This command executes capture from deck sequence. Parameters:

• IN, OUT - timecodes in format HH:MM:SS:FF, or
• LIMIT - frame count to capture, this can be extended later with RECORDER CALL n LIMIT l
• FILE - name of file with extension, file will record in caspar's media directory,
• NARROW - allows to specify display aspect ratio for Standard Definition formats,
• ACODEC, VCODEC - optional audio and video codec according to FFmpeg documentation,
• ARATE, VRATE - optional bitrate in kilobytes/s
• OPTIONS - optional comma-separated list of format and/or codec specific options according to FFmpeg documentation, in format option_name=option_value.

RECORDER [PLAY|STOP|ABORT|FF|REWIND|GOTO|FINISH|LIMIT] [recorder_index]

Commands PLAY-GOTO are to perform basic deck control operations (e.g RECORDER PLAY 1). In case of GOTO additional parameter TC is required, e.g. RECORDER GOTO 1 TC 10:0:0:20

FINISH command e.g. RECORDER FINISH 1 prematurely finishes capture operation,

CALL command allows to extend/shrink limited frames capture operation to a new frame count, e.g. RECORDER CALL 1 LIMIT 5000