17.06.2016, 16:29, Mark Hills kirjoitti: > Hi, Hi, > Is there any provision in ALSA (either within the kernel or libasound) for > extracting track marker information from S/PDIF? I don't know what track marker data looks like, but see below. > I have a large number of MiniDisc recordings to preserve as FLAC format. > > Losing track markers would be a huge inconvenience, though I don't care > for the rest of the metadata (track names etc..) > > There's enough recordings to be worth developing specific software for the > archival if it can access this information. > > I don't really know which path is likely to be successful: > > * An ALSA API to access the information; though I can't see anything > specific to track markers > > * Whether a timecode could be used to detect track change; but I can't see > any in /proc/asound/Layla3G/status > > * Does ALSA provide access to raw AES streams, so I could decode it in > userland? I'm un-sure if this relates to hardware AC3 decoding. ALSA does provide access to the raw stream with drivers that support that. You'll need to record with IEC958_SUBFRAME_LE or IEC958_SUBFRAME_BE sample formats. > * Maybe this sort of status is only available to the firmware of the > interface and never makes it to userland (in my case, echo3g); though I > can see some constants relating to 'non audio' S/PDIF. Unfortunately the echo3g driver doesn't seem to support IEC958_SUBFRAME_* sample formats. The HDA driver, used for most mainboard/laptop integrated audio, does support that format if the hardware is capable. I'm not sure if the hardware commonly supports that format or not, though. > The hardware I have here is Echo Layla 3G (snd-echo3g) and a Pioneer > MJ-D707 MiniDisc recorder. > > Any advice appreciated -- many thanks. > -- Anssi Hannula _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
