Play Audio Track Relative(10)
2.15Play Audio Track Relative(10) (49h)
Operation Code is (49h).
TRLBA
The Track Relative Logical Block Address field specifies the two's complement starting logical block address relative to the beginning of the first sector on the track with an index value of one. Negative values indicate a starting location within the audio pause area at the beginning of the requested track.
Starting Track
Specifies the track number of the starting audio track.
Transfer Length
The Transfer Length Field specifies the number of contiguous logical blocks that shall be output as audio data. A length of zero indicates that no audio playback operation shall occur. This condition is not an error. Any other value indicates the number of logical blocks that shall be output.
The PLAY AUDIO TRACK RELATIVE(10) command requests that the drive begin an audio playback operation. The starting address is specified as a track relative logical block address within the specified starting track. The command function (Immed and SOTC bits) and the output of audio signals shall be as specified by the settings of the mode parameters.
If the logical block length is not equal to the sector size the drive will adjust the starting logical block address and the transfer length. The drive will start the audio play operation with the beginning of a sector whenever the starting logical address falls within that sector (MSF unit). If the requested transfer length causes the end of an audio play operation to fall within a sector the drive will continue the play operation through the end of that sector.
If the starting address is not found, or if the address is not within an audio track, or if a not ready condition exists, the command is terminated with Check Condition status.
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