An option for the MRD 3187A/B, the 8704B is a standard definition video output card. It provides two mirrored serial digital (SMPTE 259M) outputs and one composite NTSC & PAL output. Four pairs of audio can be embedded into the serial output on group 1 and 2. Closed captioning found within the transport (608/708B) can be embedded into the serial video output. NTSC closed caption, detected in the transport stream, can be inserted on line 21.