Read CD-ROM Capacity
Support of Sub-channel data is optional. In the case of R-W the drive may return data de- interleaved and error-corrected, RAW or padded with zeros depending on the R-W Supported and R-W de-interleaved and error-corrected bits in the CD-ROM capabilities and mechanical status page.
If the Starting Logical Block Address is set to FFFFFFFFh and the only information requested to be placed in the data stream is the Sub-channel data and there is currently a PLAY AUDIO command in process, the actual address used will be from the current location (of the Audio play).
The number of bytes returned is based on which bits are set in the Data Selection Field.
The table on the opposite page allows you to calculate the number of bytes returned based on which Data Selection field bits are set.
The CD-DA audio data includes 16bits of information for each channel, and will be formatted as follows when an audio track is read. The First Channel is Left channel, and Right channel is next.