I am researching the reasons behind number of link sectors used by packet writing mode of CD-RW/R disks.
At this point I know the following information:
- CD sector consists of 98 audio frames.
Audio frames are passed through delay lines, and reed solomon codes are added to each.
Incoming data is split into 24 one byte channels.
Each channel is passed through CIRC encoder, which adds reed solomon codes, and delays each channel by variable number of bytes.
Therefore, after you write 98 frames, you still need to write lot more frames which will be partially filled with zeros.
In fact, when you write 108 frame, it will still contain one byte from 1st frame before CIRC.
Thus it appears to be logical to have 2 run-in blocks, and 2 run-out blocks.
However I don't understand why there is a need for whole 4 run-in blocks.
In addition to that, could you tell me the layout of variable packet?
(can't seem to find that on the webs)
Thanks in advance