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[Openvortex-dev] Re: [Alsa-devel] au88x0 - Replace spdif frequency contr


From: Raymond
Subject: [Openvortex-dev] Re: [Alsa-devel] au88x0 - Replace spdif frequency control by IEC958 control
Date: Wed, 23 Feb 2005 10:19:58 +0800
User-agent: Mozilla/5.0 (X11; U; Linux i686; zh-CN; rv:1.4.3) Gecko/20041005

1) What is the difference between Consumer mode and Professional mode ?

A different set of status bits.  See, for example, ALSA"s asoundef.h,
but it doesn"t have many explanations.

The main difference is that only consumer mode has the copyright bit
so that devices can automatically disable copying.


The parameter 'spdif_mode' in the routine vortex_spdif_init(vortex,spdif_sr,spdif_mode) in au88x0_core.c seems to control AC3 passthrough.

However the two memory mapped I/O VORTEX_SPDIF_CFG0 and VORTEX_SPDIF_CFG1 seem to be write-only, return zero when read.

The value of memory mapped I/O VORTEX_SPDIF_FLAGS are changing between 00138014 and 00138015

1) Which bit in the IEC958 control is related to AC3 passthrough ?

As vortex_spdif_init() only handle changing SPDIF sample rate.

2) Do the driver need to initialise vortex->spdif_sr to 48000 or just let alsactl restore the value from /etc/asound.state ?

3) Is it correct to return the following value in snd_vortex_spdif_mask_get() ?
ucontrol->value.iec958.status[3] = IEC958_AES3_CON_FS;

4) Is it correct to return the following value in snd_vortex_spdif_default_get() ? ucontrol->value.iec958.status[1] =IEC958_AES1_CON_ORIGINAL | IEC958_AES1_CON_DIGDIGCONV_ID;

5) What additional kcontrol and routine are needed for SPDIF IN ?










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