wolfgang buresch <[EMAIL PROTECTED]> writes:
> > > I just read on the MDCP the faq about ATRAC3 at > > > http://www.minidisc.org/mdlpfaq.html and it says for Q#10: "What > > > bitrates are used?" A:".....In LP2 and LP4 modes 20 bytes of dummy > > > data per 212 byte soundgroup......" --> those 20 bytes -- are they a > > > fact or just a wild guess? > > > > Fact. I double checked it with Sony. > > Sorry, my fault, but I guess I was misunderstood. I understand that ATRAC3 has to be > somehow embedded into ATRAC1 and I know that that's a fact. What I meant was whether >the > number of bytes (20) are a fact or not (Why not 19 or 21 bytes per SG). For, you only > need 13 bytes per soundgroup to produce silence. I even could ask differently. If we > were ask to define the "new" ATRAC3 algorithm and we know we have to embed it into > ATRAC1, why come up with 132kbps? Why waste 7 bytes per SG for nothing? Think about >it, > we have 775.104 SoundGroups available for recording, that means we are wasting more >than > 5MB per 74m59s disc and there is "no future use" for that space. Right. I received the "20 bytes" number from Sony after publishing an initially incorrect guess at the number of bytes needed to produce silence in ATRAC1. My guess is that 132kbps is really just the average, and that the extra "unusused" space is actually slop space for the Huffman encoder. Since Huffman coding exploits redundancy in the information to be encoded, some signals will require more space than others (just as with .zip files). > ps: last Q: Does anyone know why the very first ATRAC coder [ATRAC1 Version1 (MZ-1)] > sounded soo bad. (I know the answer, but before I am going to post it I want to have > your thoughts). The 16 bit math? Rick ----------------------------------------------------------------- To stop getting this list send a message containing just the word "unsubscribe" to [EMAIL PROTECTED]
