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);
107 date_Init (&owner->sync.date, owner->mixer_format.i_rate, 1);
108 date_Set (&owner->sync.date, VLC_TS_INVALID);
110 owner->input = p_input;
111 aout_InputNew( p_aout, p_input, p_request_vout );
112 aout_unlock( p_aout );
115 aout_unlock( p_aout );
120 /*****************************************************************************
121 * aout_DecDelete : delete a decoder
122 *****************************************************************************/
123 void aout_DecDelete( audio_output_t * p_aout )
125 aout_owner_t *owner = aout_owner (p_aout);
127 struct audio_mixer *mixer;
130 /* Remove the input. */
131 input = owner->input;
132 aout_InputDelete (p_aout, input);
135 aout_OutputDelete( p_aout );
136 mixer = owner->volume.mixer;
137 owner->volume.mixer = NULL;
138 var_Destroy( p_aout, "audio-device" );
139 var_Destroy( p_aout, "audio-channels" );
141 aout_unlock( p_aout );
143 aout_MixerDelete (mixer);
147 static void aout_CheckRestart (audio_output_t *aout)
149 aout_owner_t *owner = aout_owner (aout);
150 aout_input_t *input = owner->input;
152 aout_assert_locked (aout);
154 if (likely(!owner->need_restart))
156 owner->need_restart = false;
158 /* Reinitializes the output */
159 aout_InputDelete (aout, owner->input);
160 aout_MixerDelete (owner->volume.mixer);
161 owner->volume.mixer = NULL;
162 aout_OutputDelete (aout);
164 if (aout_OutputNew (aout, &input->input))
166 input->b_error = true;
167 return; /* we are officially screwed */
170 owner->volume.mixer = aout_MixerNew (aout, owner->mixer_format.i_format);
172 if (aout_InputNew (aout, input, &input->request_vout))
173 assert (input->b_error);
175 assert (!input->b_error);
183 /*****************************************************************************
184 * aout_DecNewBuffer : ask for a new empty buffer
185 *****************************************************************************/
186 block_t *aout_DecNewBuffer (audio_output_t *aout, size_t samples)
188 /* NOTE: the caller is responsible for serializing input change */
189 aout_owner_t *owner = aout_owner (aout);
190 aout_input_t *input = owner->input;
192 size_t length = samples * input->input.i_bytes_per_frame
193 / input->input.i_frame_length;
194 block_t *block = block_Alloc( length );
195 if( likely(block != NULL) )
197 block->i_nb_samples = samples;
198 block->i_pts = block->i_length = 0;
203 /*****************************************************************************
204 * aout_DecDeleteBuffer : destroy an undecoded buffer
205 *****************************************************************************/
206 void aout_DecDeleteBuffer (audio_output_t *aout, block_t *block)
209 aout_BufferFree (block);
212 /*****************************************************************************
213 * aout_DecPlay : filter & mix the decoded buffer
214 *****************************************************************************/
215 int aout_DecPlay (audio_output_t *p_aout, block_t *p_buffer, int i_input_rate)
217 aout_owner_t *owner = aout_owner (p_aout);
218 aout_input_t *p_input = owner->input;
220 assert( i_input_rate >= INPUT_RATE_DEFAULT / AOUT_MAX_INPUT_RATE &&
221 i_input_rate <= INPUT_RATE_DEFAULT * AOUT_MAX_INPUT_RATE );
222 assert( p_buffer->i_pts > 0 );
224 p_buffer->i_length = (mtime_t)p_buffer->i_nb_samples * 1000000
225 / p_input->input.i_rate;
228 if( p_input->b_error )
230 aout_unlock( p_aout );
231 aout_BufferFree( p_buffer );
235 aout_CheckRestart( p_aout );
236 aout_InputCheckAndRestart( p_aout, p_input );
239 p_buffer = aout_InputPlay (p_aout, p_input, p_buffer, i_input_rate,
241 if( p_buffer != NULL )
243 date_Increment (&owner->sync.date, p_buffer->i_nb_samples);
246 float amp = owner->volume.multiplier * p_input->multiplier;
247 aout_MixerRun (owner->volume.mixer, p_buffer, amp);
250 aout_OutputPlay( p_aout, p_buffer );
253 aout_unlock( p_aout );
257 int aout_DecGetResetLost (audio_output_t *aout)
259 aout_owner_t *owner = aout_owner (aout);
260 aout_input_t *input = owner->input;
264 val = input->i_buffer_lost;
265 input->i_buffer_lost = 0;
271 void aout_DecChangePause (audio_output_t *aout, bool paused, mtime_t date)
273 aout_owner_t *owner = aout_owner (aout);
276 /* XXX: Should the date be offset by the pause duration instead? */
277 date_Set (&owner->sync.date, VLC_TS_INVALID);
278 aout_OutputPause (aout, paused, date);
282 void aout_DecFlush (audio_output_t *aout)
284 aout_owner_t *owner = aout_owner (aout);
287 date_Set (&owner->sync.date, VLC_TS_INVALID);
288 aout_OutputFlush (aout, false);
292 bool aout_DecIsEmpty (audio_output_t *aout)
294 aout_owner_t *owner = aout_owner (aout);
298 /* FIXME: tell output to drain */
299 end_date = date_Get (&owner->sync.date);
301 return end_date == VLC_TS_INVALID || end_date <= mdate();
305 * Notifies the audio input of the drift from the requested audio
306 * playback timestamp (@ref block_t.i_pts) to the anticipated playback time
307 * as reported by the audio output hardware.
308 * Depending on the drift amplitude, the input core may ignore the drift
309 * trigger upsampling or downsampling, or even discard samples.
310 * Future VLC versions may instead adjust the input decoding speed.
312 * The audio output plugin is responsible for estimating the ideal current
313 * playback time defined as follows:
314 * ideal time = buffer timestamp - (output latency + pending buffer duration)
316 * Practically, this is the PTS (block_t.i_pts) of the current buffer minus
317 * the latency reported by the output programming interface.
318 * Computing the estimated drift directly would probably be more intuitive.
319 * However the use of an absolute time value does not introduce extra
320 * measurement errors due to the CPU scheduling jitter and clock resolution.
321 * Furthermore, the ideal while it is an abstract value, is easy for most
322 * audio output plugins to compute.
323 * The following definition is equivalent but depends on the clock time:
324 * ideal time = real time + drift
326 * @note If aout_LatencyReport() is never called, the core will assume that
329 * @param ideal estimated ideal time as defined above.
331 void aout_TimeReport (audio_output_t *aout, mtime_t ideal)
333 mtime_t delta = mdate() - ideal /* = -drift */;
335 aout_assert_locked (aout);
336 if (delta < -AOUT_MAX_PTS_ADVANCE || +AOUT_MAX_PTS_DELAY < delta)
338 aout_owner_t *owner = aout_owner (aout);
340 msg_Warn (aout, "not synchronized (%"PRId64" us), resampling",
342 if (date_Get (&owner->sync.date) != VLC_TS_INVALID)
343 date_Move (&owner->sync.date, delta);