format extension patchset available (24bit support on USB audio)

format extension patchset available (24bit support on USB audio)

[Takashi Iwai]

Hi,

i finished the extension of alsa-driver/lib for supporting
3-bytes-packed formats.
the patches are found at

	http://www.alsa-project.org/~iwai/alsa-kernel-fmt-ext.dif.gz
	http://www.alsa-project.org/~iwai/alsa-driver-fmt-ext.dif.gz
	http://www.alsa-project.org/~iwai/alsa-lib-fmt-ext.dif.gz

the patches are to the latest cvs.

the patch will extend the format mask bitmap from 32 to 256
(configurable in the source code) and include conversion between
3-bytes and other conventional formats.

the kernel api will be incompatible with the older one due to this
change, so you'll need to update alsa-lib together with alsa-driver.
the applications work without recompiling.  just replace alsa-lib.

the usb 24bit formats should work with this patchset, but most likely
they are packed in 3-bytes, which is not supported by most
applications natively.  thus you'll need to use a plugin layer, i.e.
specify "plughw:X,Y" as a pcm name.

also, OSS emulation module doesn't support 3-bytes format.
i don't think it matters, because OSS doesn't support 24bit format
anyway, and all usb devices i've known support 16bit format in
addition to high-bit formats.


any feedbacks are appreciated.


ciao,

Takashi

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