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From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To: Raymond Yau <superquad.vortex2@gmail.com>
Cc: ALSA Development Mailing List <alsa-devel@alsa-project.org>
Subject: Re: [PATCH RFC 0/9] audio timestamping evolutions
Date: Fri, 12 Dec 2014 09:28:46 -0600	[thread overview]
Message-ID: <548B09AE.1090000@linux.intel.com> (raw)
In-Reply-To: <CAN8cciY0_2_FamMDSVkz77D_DwpfZFT-PVv7Cx-Q=+7N1Of0ag@mail.gmail.com>


>
> #define PERIOD 6000
>
> #define PLAYBACK_BUFFERS 4
>
> unsigned char buffer_p[PERIOD*4*4];
> unsigned char buffer_c[PERIOD*4*4];
>
> I don't understand why you hard coded PERIOD and PLAYBACK_BUFFERS
> when you use snd_pcm_set_params

Thanks for pointing this out. I have no idea what this is still there, i 
think the idea was to use a fixed-size buffer to make sure the timing is 
predictable, it's been that way for 2+ years. Will fix.

>
> since period size and buffer size can be obtained by
> snd_pcm_get_params() after calling snd_pcm_set_params()
>
> if ((err = snd_pcm_set_params(handle_p,
>                                SND_PCM_FORMAT_S16,
>                                SND_PCM_ACCESS_RW_INTERLEAVED,
>                                2,
>                                48000,
>                                0,
>                                500000)) < 0) { /* 0.5sec */
>

  reply	other threads:[~2014-12-12 15:28 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-08 22:23 [PATCH RFC 0/9] audio timestamping evolutions Pierre-Louis Bossart
2014-12-08 22:23 ` [PATCH RFC 1/9] ALSA: core: don't override timestamp unconditionally Pierre-Louis Bossart
2014-12-08 22:23 ` [PATCH RFC 2/9] ALSA: core: allow for trigger_tstamp snapshot in .trigger Pierre-Louis Bossart
2014-12-10 16:31   ` Takashi Iwai
2014-12-10 17:22     ` Pierre-Louis Bossart
2014-12-10 17:35       ` Takashi Iwai
2014-12-10 18:43         ` Pierre-Louis Bossart
2014-12-10 19:20           ` Takashi Iwai
2014-12-08 22:23 ` [PATCH RFC 3/9] ALSA: hda: read trigger_timestamp immediately after starting DMA Pierre-Louis Bossart
2014-12-08 22:23 ` [PATCH RFC 4/9] ALSA: usb: update trigger timestamp on first non-zero URB submitted Pierre-Louis Bossart
2014-12-08 22:23 ` [PATCH RFC 5/9] ALSA: core: selection of audio_tstamp type and accuracy reports Pierre-Louis Bossart
2014-12-10 16:35   ` Takashi Iwai
2014-12-10 17:27     ` Pierre-Louis Bossart
2014-12-10 17:39       ` Takashi Iwai
2014-12-10 20:08         ` Takashi Iwai
2014-12-10 21:48           ` Pierre-Louis Bossart
2014-12-10 22:27             ` Takashi Iwai
2014-12-10 23:04               ` Pierre-Louis Bossart
2014-12-11  5:54                 ` Takashi Iwai
2014-12-12  2:36                   ` Pierre-Louis Bossart
2014-12-12  8:37                     ` Takashi Iwai
2014-12-12 15:20                       ` Pierre-Louis Bossart
2014-12-14 15:03                         ` Takashi Iwai
2014-12-16 14:01               ` Tim Cussins
2014-12-08 22:23 ` [PATCH RFC 6/9] ALSA: core: pass audio tstamp config from userspace Pierre-Louis Bossart
2014-12-10 17:28   ` Takashi Iwai
2014-12-10 17:35     ` Pierre-Louis Bossart
2014-12-10 17:40       ` Takashi Iwai
2014-12-08 22:23 ` [PATCH RFC 7/9] ALSA: core: pass audio tstamp config from userspace in compat mode Pierre-Louis Bossart
2014-12-08 22:23 ` [PATCH RFC 8/9] ALSA: core: replace .wall_clock by .get_time_info Pierre-Louis Bossart
2014-12-08 22:23 ` [PATCH RFC 9/9] ALSA: hda: replace .wallclock " Pierre-Louis Bossart
2014-12-10  4:40 ` [PATCH RFC 0/9] audio timestamping evolutions Raymond Yau
2014-12-10 14:55   ` Pierre-Louis Bossart
2014-12-12  4:55     ` Raymond Yau
2014-12-12 15:28       ` Pierre-Louis Bossart [this message]
2014-12-14  3:34         ` Raymond Yau

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