1 /*****************************************************************************
2 * dec.c : audio output API towards decoders
3 *****************************************************************************
4 * Copyright (C) 2002-2007 the VideoLAN team
7 * Authors: Christophe Massiot <massiot@via.ecp.fr>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22 *****************************************************************************/
24 /*****************************************************************************
26 *****************************************************************************/
33 #include <vlc_common.h>
36 #include <vlc_input.h>
38 #include "aout_internal.h"
42 * Creates an audio output
44 int aout_DecNew( audio_output_t *p_aout,
45 const audio_sample_format_t *p_format,
46 const audio_replay_gain_t *p_replay_gain,
47 const aout_request_vout_t *p_request_vout )
49 /* Sanitize audio format */
50 if( p_format->i_channels > 32 )
52 msg_Err( p_aout, "too many audio channels (%u)",
53 p_format->i_channels );
56 if( p_format->i_channels <= 0 )
58 msg_Err( p_aout, "no audio channels" );
61 if( p_format->i_channels != aout_FormatNbChannels( p_format ) )
63 msg_Err( p_aout, "incompatible audio channels count with layout mask" );
67 if( p_format->i_rate > 192000 )
69 msg_Err( p_aout, "excessive audio sample frequency (%u)",
73 if( p_format->i_rate < 4000 )
75 msg_Err( p_aout, "too low audio sample frequency (%u)",
80 aout_input_t *p_input = calloc( 1, sizeof(aout_input_t));
84 p_input->b_error = true;
86 memcpy( &p_input->input, p_format,
87 sizeof(audio_sample_format_t) );
89 p_input->replay_gain = *p_replay_gain;
91 /* We can only be called by the decoder, so no need to lock
93 aout_owner_t *owner = aout_owner(p_aout);
95 assert (owner->input == NULL);
97 var_Destroy( p_aout, "audio-device" );
98 var_Destroy( p_aout, "audio-channels" );
100 /* Recreate the output using the new format. */
101 if( aout_OutputNew( p_aout, p_format ) < 0 )
104 assert (owner->volume.mixer == NULL);
105 owner->volume.mixer = aout_MixerNew (p_aout, owner->mixer_format.i_format);
106 if (owner->volume.mixer == NULL)
108 aout_OutputDelete( p_aout );
112 date_Init (&owner->sync.date, owner->mixer_format.i_rate, 1);
113 date_Set (&owner->sync.date, VLC_TS_INVALID);
115 owner->input = p_input;
116 aout_InputNew( p_aout, p_input, p_request_vout );
117 aout_unlock( p_aout );
120 aout_unlock( p_aout );
125 /*****************************************************************************
126 * aout_DecDelete : delete a decoder
127 *****************************************************************************/
128 void aout_DecDelete( audio_output_t * p_aout )
130 aout_owner_t *owner = aout_owner (p_aout);
132 struct audio_mixer *mixer;
135 /* Remove the input. */
136 input = owner->input;
137 aout_InputDelete (p_aout, input);
140 aout_OutputDelete( p_aout );
141 mixer = owner->volume.mixer;
142 owner->volume.mixer = NULL;
143 var_Destroy( p_aout, "audio-device" );
144 var_Destroy( p_aout, "audio-channels" );
146 aout_unlock( p_aout );
148 aout_MixerDelete (mixer);
152 static void aout_CheckRestart (audio_output_t *aout)
154 aout_owner_t *owner = aout_owner (aout);
155 aout_input_t *input = owner->input;
157 aout_assert_locked (aout);
159 if (likely(!owner->need_restart))
161 owner->need_restart = false;
163 /* Reinitializes the output */
164 aout_InputDelete (aout, owner->input);
165 aout_MixerDelete (owner->volume.mixer);
166 owner->volume.mixer = NULL;
167 aout_OutputDelete (aout);
169 if (aout_OutputNew (aout, &input->input))
172 input->b_error = true;
173 return; /* we are officially screwed */
176 owner->volume.mixer = aout_MixerNew (aout, owner->mixer_format.i_format);
177 if (owner->volume.mixer == NULL)
179 aout_OutputDelete (aout);
183 if (aout_InputNew (aout, input, &input->request_vout))
184 assert (input->b_error);
186 assert (!input->b_error);
194 /*****************************************************************************
195 * aout_DecNewBuffer : ask for a new empty buffer
196 *****************************************************************************/
197 block_t *aout_DecNewBuffer (audio_output_t *aout, size_t samples)
199 /* NOTE: the caller is responsible for serializing input change */
200 aout_owner_t *owner = aout_owner (aout);
201 aout_input_t *input = owner->input;
203 size_t length = samples * input->input.i_bytes_per_frame
204 / input->input.i_frame_length;
205 block_t *block = block_Alloc( length );
206 if( likely(block != NULL) )
208 block->i_nb_samples = samples;
209 block->i_pts = block->i_length = 0;
214 /*****************************************************************************
215 * aout_DecDeleteBuffer : destroy an undecoded buffer
216 *****************************************************************************/
217 void aout_DecDeleteBuffer (audio_output_t *aout, block_t *block)
220 aout_BufferFree (block);
223 /*****************************************************************************
224 * aout_DecPlay : filter & mix the decoded buffer
225 *****************************************************************************/
226 int aout_DecPlay (audio_output_t *p_aout, block_t *p_buffer, int i_input_rate)
228 aout_owner_t *owner = aout_owner (p_aout);
229 aout_input_t *p_input = owner->input;
231 assert( i_input_rate >= INPUT_RATE_DEFAULT / AOUT_MAX_INPUT_RATE &&
232 i_input_rate <= INPUT_RATE_DEFAULT * AOUT_MAX_INPUT_RATE );
233 assert( p_buffer->i_pts > 0 );
235 p_buffer->i_length = (mtime_t)p_buffer->i_nb_samples * 1000000
236 / p_input->input.i_rate;
239 if( p_input->b_error )
241 aout_unlock( p_aout );
242 aout_BufferFree( p_buffer );
246 aout_CheckRestart( p_aout );
247 aout_InputCheckAndRestart( p_aout, p_input );
250 p_buffer = aout_InputPlay (p_aout, p_input, p_buffer, i_input_rate,
252 if( p_buffer != NULL )
254 date_Increment (&owner->sync.date, p_buffer->i_nb_samples);
257 float amp = owner->volume.multiplier * p_input->multiplier;
258 aout_MixerRun (owner->volume.mixer, p_buffer, amp);
261 aout_OutputPlay( p_aout, p_buffer );
264 aout_unlock( p_aout );
268 int aout_DecGetResetLost (audio_output_t *aout)
270 aout_owner_t *owner = aout_owner (aout);
271 aout_input_t *input = owner->input;
275 val = input->i_buffer_lost;
276 input->i_buffer_lost = 0;
282 void aout_DecChangePause (audio_output_t *aout, bool paused, mtime_t date)
284 aout_owner_t *owner = aout_owner (aout);
287 /* XXX: Should the date be offset by the pause duration instead? */
288 date_Set (&owner->sync.date, VLC_TS_INVALID);
289 aout_OutputPause (aout, paused, date);
293 void aout_DecFlush (audio_output_t *aout)
295 aout_owner_t *owner = aout_owner (aout);
298 date_Set (&owner->sync.date, VLC_TS_INVALID);
299 aout_OutputFlush (aout, false);
303 bool aout_DecIsEmpty (audio_output_t *aout)
305 aout_owner_t *owner = aout_owner (aout);
309 /* FIXME: tell output to drain */
310 end_date = date_Get (&owner->sync.date);
312 return end_date == VLC_TS_INVALID || end_date <= mdate();
316 * Notifies the audio input of the drift from the requested audio
317 * playback timestamp (@ref block_t.i_pts) to the anticipated playback time
318 * as reported by the audio output hardware.
319 * Depending on the drift amplitude, the input core may ignore the drift
320 * trigger upsampling or downsampling, or even discard samples.
321 * Future VLC versions may instead adjust the input decoding speed.
323 * The audio output plugin is responsible for estimating the ideal current
324 * playback time defined as follows:
325 * ideal time = buffer timestamp - (output latency + pending buffer duration)
327 * Practically, this is the PTS (block_t.i_pts) of the current buffer minus
328 * the latency reported by the output programming interface.
329 * Computing the estimated drift directly would probably be more intuitive.
330 * However the use of an absolute time value does not introduce extra
331 * measurement errors due to the CPU scheduling jitter and clock resolution.
332 * Furthermore, the ideal while it is an abstract value, is easy for most
333 * audio output plugins to compute.
334 * The following definition is equivalent but depends on the clock time:
335 * ideal time = real time + drift
337 * @note If aout_LatencyReport() is never called, the core will assume that
340 * @param ideal estimated ideal time as defined above.
342 void aout_TimeReport (audio_output_t *aout, mtime_t ideal)
344 mtime_t delta = mdate() - ideal /* = -drift */;
346 aout_assert_locked (aout);
347 if (delta < -AOUT_MAX_PTS_ADVANCE || +AOUT_MAX_PTS_DELAY < delta)
349 aout_owner_t *owner = aout_owner (aout);
351 msg_Warn (aout, "not synchronized (%"PRId64" us), resampling",
353 if (date_Get (&owner->sync.date) != VLC_TS_INVALID)
354 date_Move (&owner->sync.date, delta);