From mboxrd@z Thu Jan 1 00:00:00 1970 From: Clemens Ladisch Subject: Re: Digital IO and SPDIF format Date: Tue, 01 Feb 2011 17:32:01 +0100 Message-ID: <4D483581.6050507@ladisch.de> References: <12de1c06449.-3167568757226561582.4620295999935056878@zoho.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by alsa0.perex.cz (Postfix) with ESMTP id CCD31245B2 for ; Tue, 1 Feb 2011 17:31:51 +0100 (CET) In-Reply-To: <12de1c06449.-3167568757226561582.4620295999935056878@zoho.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Torsten Schenk Cc: alsa-devel List-Id: alsa-devel@alsa-project.org Torsten Schenk wrote: > - if 6fire's clock and playback device's clock differ, should I use > playback device's clock (no interpolation of samples but capturing > tool might have invalid sample rate information) or the 6fire's clock > (samples need to be interpolated somehow)? You should never change the captured samples. A digital frame might be transporting AC-3/DTS data. > - should I receive a whole spdif block (usually 192 spdif frames) and > use the information I got from the block (f.ex. left/right channel > bits) before copying it to alsa or should I directly copy every frame > to alsa? When copying data from the URB buffer to ALSA's buffer, copy only the frames that are actually present. Why would you need the whole block for this? > Am I correct in assuming that SNDRV_PCM_FORMAT_IEC958_SUBFRAME_XX > samples are formatted like in the specification? Er ... the format of these samples is what the old revision of the CMI8738 chip requires. > If you know of any tool that is able to handle this format alsa-lib/src/pcm/pcm_iec958.c Regards, Clemens