src/audio/alsa/SDL_alsa_audio.h
author Sam Lantinga <slouken@lokigames.com>
Thu, 26 Apr 2001 16:45:43 +0000
changeset 0 74212992fb08
child 252 e8157fcb3114
permissions -rw-r--r--
Initial revision
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Library General Public
     7     License as published by the Free Software Foundation; either
     8     version 2 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Library General Public License for more details.
    14 
    15     You should have received a copy of the GNU Library General Public
    16     License along with this library; if not, write to the Free
    17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    18 
    19     Sam Lantinga
    20     slouken@devolution.com
    21 */
    22 
    23 #ifndef _ALSA_PCM_audio_h
    24 #define _ALSA_PCM_audio_h
    25 
    26 #include "SDL_sysaudio.h"
    27 #include <sys/asoundlib.h>
    28 
    29 /* Hidden "this" pointer for the video functions */
    30 #define _THIS	SDL_AudioDevice *this
    31 
    32 struct SDL_PrivateAudioData {
    33 	/* The audio device handle */
    34 	 snd_pcm_t *audio_handle;
    35 
    36 	/* The audio file descriptor */
    37 	int audio_fd;
    38 
    39 	/* The parent process id, to detect when application quits */
    40 	pid_t parent;
    41 
    42 	/* Raw mixing buffer */
    43 	Uint8 *pcm_buf;
    44 	int    pcm_len;
    45 
    46 	/* Support for audio timing using a timer, in addition to select() */
    47 	float frame_ticks;
    48 	float next_frame;
    49 };
    50 #define FUDGE_TICKS	10	/* The scheduler overhead ticks per frame */
    51 
    52 /* Old variable names */
    53 #define audio_handle	(this->hidden->audio_handle)
    54 #define audio_fd		(this->hidden->audio_fd)
    55 #define parent			(this->hidden->parent)
    56 #define pcm_buf			(this->hidden->pcm_buf)
    57 #define pcm_len			(this->hidden->pcm_len)
    58 #define frame_ticks		(this->hidden->frame_ticks)
    59 #define next_frame		(this->hidden->next_frame)
    60 
    61 #endif /* _ALSA_PCM_audio_h */