Re: [Libcdio-devel] CD-Text patches

[Rocky Bernstein]

On Mon, Nov 28, 2011 at 11:46 AM, Thomas Schmitt <address@hidden> wrote:

> Hi,
>
> > Since you are a nice guy,
>
> ... which compensates for my lack of sysadmin intelligence ... :))
>
> > if you want I'll convert these to text and send it to you privately.
>
> That would be great.
>
>
> > Folks all this back and forth and digging around and realizing this isn't
> > exactly in the right kind information or document format is why someone
> > should write better documents for CD Text. And if not us (where this
> issue
> > has been coming up), then by whom?
>
> I roughly know that for CD writing i would announce the Pack data in
> the upper two bits of the Data Form byte column of a CD SAO Cue Sheet.
>
> MMC-5 Table 567 says that with value 11b i can thransmit 4 Packs of
> data per frame. Footnote 3 talks of "R-W", whereas the next sentence
> under that table talks of "P-W" in Lead-in:
>  "When this Data Form of Sub-channel is selected, along with 01h
>   Data Form of Main Data, this indicates that there is an attempt
>   to write Raw P-W Sub-channel data in the Lead-in. Absolute Time
>   field should be set with the start address of the Lead-in, [...]"
> Main Data Form 01h is a CD-DA frame with no payload data. (MMC-5 Table 562)
>
> MMC-5 Table 555 gives an example of a CUE SHEET. Three rows have Data
> Form C0h, which would be Pack Data combined with Main Data Form 0
> = CD-DA payload frame.
> MMC-5 Figure 128 says that the 96 bytes of Pack Data would be appended
> to the CD-DA payload data of the frames.
>
> So my knowledge gap seems to be with the format of Pack Data
> ... although in the light of my own summary, MMC-3 appendix J might
> really fill it now.
> But i am still clueless about "R-W" sub channel and "P-W" sub channel.
>
>
> Maybe i should again study the code in the dungeon dimensions of
> libburn, whether there are more hints about sub channel.
> And the CD Device Model paragraphs of MMC-1 to MMC-6.
> Each skimming yields a bit more of insight.
>
> Still i could need an example CD which is known to deliver CD-Text
> to CD music players. Its ingredients and a recipe for cooking it
> by a free burn program would help a lot.
>

It is my hope that the files Leon recently contributed in libcdio's
test/data/cdtext.* should go a good ways towards filling this gap. At
present there may be some problems with the files, but I'm optimistic that
eventually we'll get those problems sorted out.


>
> Have a nice day :)
>
> Thomas
>
>
>