[alsa-devel] Digigram ISA cards
Hi, I'm thinking about trying to write a driver for some old Digigram cards soon, namely the PCX11 and PCX9. I might be wrong but it seems these cards natively support MPEG layers I and II and only actually support PCM by re-encoding in-driver. Does alsa-lib support MPEG conversions? Are there examples of drivers that already do this type of thing?
Please forgive my ignorance. I grepped the sources and didn't find too much info.
Ash
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At Wed, 25 Apr 2007 08:00:12 -0500, Ash Willis wrote:
Hi, I'm thinking about trying to write a driver for some old Digigram cards soon, namely the PCX11 and PCX9. I might be wrong but it seems these cards natively support MPEG layers I and II and only actually support PCM by re-encoding in-driver. Does alsa-lib support MPEG conversions?
No, and most likely won't be in as of the current form.
Are there examples of drivers that already do this type of thing?
Depends on what you need to handle. The biggest challenge would be a stream with variable bitrates. Currently, ALSA framework assumes the constant bitrate streams. If your mpeg stream is also in a constant bitrate, you may handle it simply as a special form of PCM, for example, as AC3 does right now.
Takashi
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Ash Willis -
Takashi Iwai