test/testbounds.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 07 Jul 2019 09:10:56 -0700
changeset 12928 3c4a4b1077cd
parent 12503 806492103856
permissions -rw-r--r--
Fixed bug 4710 - audio/alsa: avoid configuring hardware parameters with only a single period

Anthony Pesch

The previous code first configured the period size using snd_pcm_hw_par-
ams_set_period_size_near. Then, it further narrowed the configuration
space by calling snd_pcm_hw_params_set_buffer_size_near using a buffer
size of 2 times the _requested_ period size in order to try and get a
configuration with only 2 periods. If the configured period size was
larger than the requested size, the second call could inadvertently
narrow the configuration space to contain only a single period.

Rather than fixing the call to snd_pcm_hw_params_set_buffer_size_near
to use a size of 2 times the configured period size, the code has been
changed to use snd_pcm_hw_params_set_periods_min in order to more
clearly explain the intent.
     1 /*
     2   Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
     3 
     4   This software is provided 'as-is', without any express or implied
     5   warranty.  In no event will the authors be held liable for any damages
     6   arising from the use of this software.
     7 
     8   Permission is granted to anyone to use this software for any purpose,
     9   including commercial applications, and to alter it and redistribute it
    10   freely.
    11 */
    12 
    13 #include "SDL.h"
    14 
    15 int main(int argc, char **argv)
    16 {
    17     int total, i;
    18 
    19     if (SDL_Init(SDL_INIT_VIDEO) < 0) {
    20         SDL_Log("SDL_Init(SDL_INIT_VIDEO) failed: %s", SDL_GetError());
    21         return 1;
    22     }
    23 
    24     total = SDL_GetNumVideoDisplays();
    25     for (i = 0; i < total; i++) {
    26         SDL_Rect bounds = { -1,-1,-1,-1 }, usable = { -1,-1,-1,-1 };
    27         SDL_GetDisplayBounds(i, &bounds);
    28         SDL_GetDisplayUsableBounds(i, &usable);
    29         SDL_Log("Display #%d ('%s'): bounds={(%d,%d),%dx%d}, usable={(%d,%d),%dx%d}",
    30                 i, SDL_GetDisplayName(i),
    31                 bounds.x, bounds.y, bounds.w, bounds.h,
    32                 usable.x, usable.y, usable.w, usable.h);
    33     }
    34 
    35     SDL_Quit();
    36     return 0;
    37 }
    38 
    39 /* vi: set ts=4 sw=4 expandtab: */
    40