On Sun, 03 Apr 2016 12:27:22 +0200 "Thomas Schmitt" <[email protected]> wrote:
> There is an overall problem lurking at the horizon: > > - The command READ SUB-CHANNEL is not part of MMC-5 and MMC-6 any > more. MMC-5 was released in 2007. > cdrdao scans the sub-channel data which are replied by READ CD when > reading the whole track. > One could stop reading when the first instance of MCN or ISRC is > found in the track. MMC-5 7.5.4.18, 7.5.4.19 promise that one has to > read at most 100 blocks in order to get such an instance. Thanks for pointing that out. MMC-5 reads like the READ SUB-CHANNEL command was part of the `CD Audio External Play' feature set, which clearly is outdated. > Well, exchanging READ SUB-CHANNEL by a READ CD scan loop is a larger > job from which i refrain for now. I think we can safely postpone that for now. But eventually it should be implemented. > [...] > I wonder whether it would be desirable to unite both function bodies. Feels like the way to go to me as both use READ SUB-CHANNEL. > In another stage of metamorphosis, we could split the new function > into an SCSI transport part and an MMC interpreter part, in order to > avoid requesting more reply bytes than the drive might be willing to > return. > This might be necessary to avoid problems with operating system SCSI > passthrough drivers. (There once were and there might still be in > Linux.) I really hope that this has become unnecesary in the year 2016. Thanks for all the work you did so far! Best Regards Leon
