From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Keyon.Jey" Subject: Re: [tinycompress]how should I call compress_open for aac ltp file playback? Date: Fri, 07 Jun 2013 14:46:08 +0800 Message-ID: <51B181B0.6070001@linux.intel.com> References: <51AEDEAC.2020705@linux.intel.com> <20130605080104.GE31108@opensource.wolfsonmicro.com> <51AEF680.10209@linux.intel.com> <20130607002308.GD23045@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by alsa0.perex.cz (Postfix) with ESMTP id 90228261640 for ; Fri, 7 Jun 2013 08:44:49 +0200 (CEST) In-Reply-To: <20130607002308.GD23045@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Vinod Koul Cc: Charles Keepax , alsa-devel@alsa-project.org, "Keyon.Jey" List-Id: alsa-devel@alsa-project.org On 06/07/2013 08:23 AM, Vinod Koul wrote: > On Wed, Jun 05, 2013 at 04:27:44PM +0800, Keyon.Jey wrote: >> On 06/05/2013 04:01 PM, Charles Keepax wrote: >>> On Wed, Jun 05, 2013 at 02:46:04PM +0800, Keyon.Jey wrote: >>>> I am trying to use tinycompress for hwdecoder. everything works fine, >>>> but after compress_open (with profile = SND_AUDIOPROFILE_AAC level=0 >>>> ch_mode=0 rate_control=0), the playback of my aac-ltp-16bit-48KHz-Stereo >>>> file is faster than it should be. Am I wrong? >>> Vinod is probably the person for this one, as I am not so >>> familiar with what you guys have done internally. However, my >>> guess would be you are not setting the sample_rate correctly? It >>> likely needs to be set to the appropriate SNDRV_PCM_RATE_XXXX >>> define. The source for cplay included in the tinycompress >>> repository is a good example of using the tinycompress library. >>> >> thanks, Charles. the print log showed me that I have set >> SNDRV_PCM_RATE_48000 which seems no problem. >> the cplay example code is only for mp3 file, and it also not set >> .level, .ch_mode and .rate_control. >> Vinod, what's your suggestion? > You need to ask your firmware guys, what are they expecting the these fields. > Some decoder implementations can be different. But i would expect the audio to > be broken, bad quality if that is the case. > > But the speed of playback can be due to different decoder output rate and > different sampling rate configured. You are telling decoder 48Khz as CPM sample > rate, is that what decoder is understanding and conversion to decoder values > correct. Then you should check if the rendering to DAC is at 48KHz or not. > > -- > ~Vinod > thanks, Vinod, I will check with the firmware guys for these detail fields. ~Keyon