1 /*****************************************************************************
2 * aout.c : QNX audio output
3 *****************************************************************************
4 * Copyright (C) 2000, 2001 the VideoLAN team
6 * Authors: Henri Fallon <henri@videolan.org>
7 * Jon Lech Johansen <jon-vl@nanocrew.net>
8 * Pascal Levesque <pascal.levesque@mindready.com>
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
23 *****************************************************************************/
25 /*****************************************************************************
27 *****************************************************************************/
28 #include <errno.h> /* ENOMEM */
34 #include <vlc_common.h>
38 #include <sys/asoundlib.h>
42 snd_pcm_t * p_pcm_handle;
46 uint8_t * p_silent_buffer;
49 #define DEFAULT_FRAME_SIZE 2048
51 /*****************************************************************************
53 *****************************************************************************/
54 int OpenAudio ( vlc_object_t *p_this );
55 void CloseAudio ( vlc_object_t *p_this );
56 static int GetBufInfo ( aout_instance_t * );
57 static void Play ( aout_instance_t * );
58 static void* QNXaoutThread ( vlc_object_t * );
60 /*****************************************************************************
61 * Open : creates a handle and opens an alsa device
62 *****************************************************************************
63 * This function opens an alsa device, through the alsa API
64 *****************************************************************************/
65 int OpenAudio( vlc_object_t *p_this )
67 aout_instance_t *p_aout = (aout_instance_t *)p_this;
69 int i_bytes_per_sample;
71 snd_pcm_channel_info_t pi;
72 snd_pcm_channel_params_t pp;
73 aout_instance_t *p_aout = (aout_instance_t *)p_this;
75 /* allocate structure */
76 p_aout->output.p_sys = malloc( sizeof( aout_sys_t ) );
77 if( p_aout->output.p_sys == NULL )
80 /* open audio device */
81 if( ( i_ret = snd_pcm_open_preferred( &p_aout->output.p_sys->p_pcm_handle,
82 &p_aout->output.p_sys->i_card,
83 &p_aout->output.p_sys->i_device,
84 SND_PCM_OPEN_PLAYBACK ) ) < 0 )
86 msg_Err( p_aout, "unable to open audio device (%s)",
87 snd_strerror( i_ret ) );
88 free( p_aout->output.p_sys );
93 if( ( i_ret = snd_pcm_plugin_set_disable( p_aout->output.p_sys->p_pcm_handle,
94 PLUGIN_DISABLE_MMAP ) ) < 0 )
96 msg_Err( p_aout, "unable to disable mmap (%s)", snd_strerror(i_ret) );
98 free( p_aout->output.p_sys );
102 p_aout->output.p_sys->p_silent_buffer = malloc( DEFAULT_FRAME_SIZE * 4 );
103 p_aout->output.pf_play = Play;
104 aout_VolumeSoftInit( p_aout );
106 memset( &pi, 0, sizeof(pi) );
107 memset( &pp, 0, sizeof(pp) );
109 pi.channel = SND_PCM_CHANNEL_PLAYBACK;
110 if( ( i_ret = snd_pcm_plugin_info( p_aout->output.p_sys->p_pcm_handle,
113 msg_Err( p_aout, "unable to get plugin info (%s)",
114 snd_strerror( i_ret ) );
115 CloseAudio( p_this );
116 free( p_aout->output.p_sys );
120 pp.mode = SND_PCM_MODE_BLOCK;
121 pp.channel = SND_PCM_CHANNEL_PLAYBACK;
122 pp.start_mode = SND_PCM_START_FULL;
123 pp.stop_mode = SND_PCM_STOP_STOP;
125 pp.buf.block.frags_max = 3;
126 pp.buf.block.frags_min = 1;
128 pp.format.interleave = 1;
129 pp.format.rate = p_aout->output.output.i_rate;
131 i_nb_channels = aout_FormatNbChannels( &p_aout->output.output );
132 if ( i_nb_channels > 2 )
134 /* I don't know if QNX supports more than two channels. */
136 p_aout->output.output.i_channels = AOUT_CHAN_STEREO;
138 pp.format.voices = i_nb_channels;
140 p_aout->output.output.i_format = VLC_CODEC_S16N;
141 p_aout->output.i_nb_samples = DEFAULT_FRAME_SIZE;
142 pp.format.format = SND_PCM_SFMT_S16;
143 i_bytes_per_sample = 2;
145 pp.buf.block.frag_size = p_aout->output.i_nb_samples *
146 p_aout->output.output.i_channels *
150 if( ( i_ret = snd_pcm_plugin_params( p_aout->output.p_sys->p_pcm_handle,
153 msg_Err( p_aout, "unable to set parameters (%s)", snd_strerror(i_ret) );
154 CloseAudio( p_this );
155 free( p_aout->output.p_sys );
159 /* prepare channel */
160 if( ( i_ret = snd_pcm_plugin_prepare( p_aout->output.p_sys->p_pcm_handle,
161 SND_PCM_CHANNEL_PLAYBACK ) ) < 0 )
163 msg_Err( p_aout, "unable to prepare channel (%s)",
164 snd_strerror( i_ret ) );
165 CloseAudio( p_this );
166 free( p_aout->output.p_sys );
170 /* Create audio thread and wait for its readiness. */
171 if( vlc_thread_create( p_aout, "aout", QNXaoutThread,
172 VLC_THREAD_PRIORITY_OUTPUT ) )
174 msg_Err( p_aout, "cannot create QNX audio thread (%m)" );
175 CloseAudio( p_this );
176 free( p_aout->output.p_sys );
183 /*****************************************************************************
184 * GetBufInfo: buffer status query
185 *****************************************************************************
186 * This function returns the number of used byte in the queue.
187 * It also deals with errors : indeed if the device comes to run out
188 * of data to play, it switches to the "underrun" status. It has to
189 * be flushed and re-prepared
190 *****************************************************************************/
191 static int GetBufInfo( aout_instance_t *p_aout )
194 snd_pcm_channel_status_t status;
196 /* get current pcm status */
197 memset( &status, 0, sizeof(status) );
198 if( ( i_ret = snd_pcm_plugin_status( p_aout->output.p_sys->p_pcm_handle,
201 msg_Err( p_aout, "unable to get device status (%s)",
202 snd_strerror( i_ret ) );
206 /* check for underrun */
207 switch( status.status )
209 case SND_PCM_STATUS_READY:
210 case SND_PCM_STATUS_UNDERRUN:
211 if( ( i_ret = snd_pcm_plugin_prepare( p_aout->output.p_sys->p_pcm_handle,
212 SND_PCM_CHANNEL_PLAYBACK ) ) < 0 )
214 msg_Err( p_aout, "unable to prepare channel (%s)",
215 snd_strerror( i_ret ) );
220 return( status.count );
223 /*****************************************************************************
224 * Play : plays a sample
225 *****************************************************************************
226 * Plays a sample using the snd_pcm_write function from the alsa API
227 *****************************************************************************/
228 static void Play( aout_instance_t *p_aout )
232 /*****************************************************************************
233 * CloseAudio: close the audio device
234 *****************************************************************************/
235 void CloseAudio ( vlc_object_t *p_this )
237 aout_instance_t *p_aout = (aout_instance_t *)p_this;
240 vlc_object_kill( p_aout );
241 vlc_thread_join( p_aout );
243 if( ( i_ret = snd_pcm_close( p_aout->output.p_sys->p_pcm_handle ) ) < 0 )
245 msg_Err( p_aout, "unable to close audio device (%s)",
246 snd_strerror( i_ret ) );
249 free( p_aout->output.p_sys->p_silent_buffer );
250 free( p_aout->output.p_sys );
254 /*****************************************************************************
255 * QNXaoutThread: asynchronous thread used to DMA the data to the device
256 *****************************************************************************/
257 static void* QNXaoutThread( vlc_object_t *p_this )
259 aout_instance_t * p_aout = (aout_instance_t*)p_this;
260 struct aout_sys_t * p_sys = p_aout->output.p_sys;
261 int canc = vlc_savecancel ();
263 while ( vlc_object_alive (p_aout) )
265 aout_buffer_t * p_buffer;
269 if ( p_aout->output.output.i_format != VLC_CODEC_SPDIFL )
271 mtime_t next_date = 0;
273 /* Get the presentation date of the next write() operation. It
274 * is equal to the current date + duration of buffered samples.
275 * Order is important here, since GetBufInfo is believed to take
276 * more time than mdate(). */
277 next_date = (mtime_t)GetBufInfo( p_aout ) * 1000000
278 / p_aout->output.output.i_bytes_per_frame
279 / p_aout->output.output.i_rate
280 * p_aout->output.output.i_frame_length;
281 next_date += mdate();
283 p_buffer = aout_OutputNextBuffer( p_aout, next_date, false );
287 p_buffer = aout_OutputNextBuffer( p_aout, 0, true );
290 if ( p_buffer != NULL )
292 p_bytes = p_buffer->p_buffer;
293 i_size = p_buffer->i_buffer;
297 i_size = DEFAULT_FRAME_SIZE / p_aout->output.output.i_frame_length
298 * p_aout->output.output.i_bytes_per_frame;
299 p_bytes = p_aout->output.p_sys->p_silent_buffer;
300 memset( p_bytes, 0, i_size );
303 i_tmp = snd_pcm_plugin_write( p_aout->output.p_sys->p_pcm_handle,
309 msg_Err( p_aout, "write failed (%m)" );
312 if ( p_buffer != NULL )
314 aout_BufferFree( p_buffer );
318 vlc_restorecancel (canc);