From alsa-devel-owner@alsa.jcu.cz  Sun Oct  4 19:11:47 1998
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	Sun, 4 Oct 1998 19:11:34 +0200
Date: Sun, 4 Oct 1998 19:11:32 +0200 (CEST)
From: Jaroslav Kysela <perex@jcu.cz>
To: Alan Robinson <robinson@vt.edu>
cc: alsa-devel@alsa.jcu.cz
Subject: RE: PCM mixing draft v0.2
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On Sun, 4 Oct 1998, Alan Robinson wrote:

> The only comment I have is that it seems to be missing control of panning of a
> PCM.... However, I might have missed elsewhere in the library where you can
> set panning for a channel, which would do the same thing...  Ideally, there
> should be a nice userland api which lets you say PlaySndMixed(file, volume,
> panning);, which would just start the process and return.  Then, however, we
> are getting into threads, a somewhat sticky issue.

It's true. Thank you for idea. What about this:

struct snd_pcm_mix_setup {
  unsigned char lvolume[128];           /* linear left volume levels (0-255) */
  unsigned char rvolume[128];           /* linear right volume levels (0-255) */
  unsigned int format;                  /* SND_PCM_SFMT_XXXX - data format */
  unsigned int rate;                    /* rate (if info returns variable rate otherwise it must be set to mixing rate) */
  unsigned int channels;                /* channels (voices) */
  struct timeval start;                 /* start time in us or zero=now */
  unsigned int size;                    /* buffer size in bytes or zero=initial */
  int wakeup_size;                      /* wakeup size in bytes */
  unsigned char reserved[256];          /* reserved for future */
};

						Jaroslav

-----
Jaroslav Kysela <perex@jcu.cz>
Academic Computer Centre, University of South Bohemia
Branisovska 31, C. Budejovice, CZ-370 05 Czech Republic




