[alsa-devel] using plug for sample format conversion

Adam Rosenberg adam at alcorn.com
Wed Jul 28 18:55:03 CEST 2010

>> I am trying to use plug to play audio files that are S16_LE but my
>> hardware only supports S32_LE.  It is not working.  Here is an example
>> of the problem using speaker-test.  First I use S32_LE and it works as
>> expected.  I then try S16_LE but it fails.  Does this mean the plug
>> plugin cannot convert between these sample formats?
>> Thanks,
>> Adam
>Please use latest version of speaker-test and alsa-lib.
>and post struct  snd_pcm_hardware of you driver

I am using the latest release of uClinux for Blackfin BF537 and do not
know how to configure and install the latest version of alsa-lib and
alsa-utils.  I am starting to understand how struct snd_pcm_hardware
is used by the ALSA PCM code but you are correct to assume I may have
something wrong.  Here is the struct:

static struct snd_pcm_hardware ourCS42448PcmHw =
	.formats = SNDRV_PCM_FMTBIT_S32_LE,
	.rates = SNDRV_PCM_RATE_48000,
	.rate_min = 48000,
	.rate_max = 48000,
	.buffer_bytes_max = 32768,
	.channels_min = 1,
	.channels_max = 2,
	.period_bytes_max = 32768,
	.periods_min = 1,
	.period_bytes_min = 8,
	.periods_max = 4096,

Can you tell me how to configure and install the latest ALSA and
whether the snd_pcm_hardware is correct?


Adam Rosenberg
Software Engineer

Alcorn McBride Inc.
3300 South Hiawassee
Building 105
Orlando, FL 32835

(407) 296 - 5800 ext. 5490

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