1 /*****************************************************************************
2 * linear.c : linear interpolation resampler
3 *****************************************************************************
4 * Copyright (C) 2002, 2006 the VideoLAN team
7 * Authors: Gildas Bazin <gbazin@netcourrier.com>
8 * Sigmund Augdal Helberg <dnumgis@videolan.org>
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 *****************************************************************************/
33 #include <vlc_common.h>
34 #include <vlc_plugin.h>
36 #include <vlc_filter.h>
37 #include <vlc_block.h>
39 /*****************************************************************************
41 *****************************************************************************/
42 static int Create ( vlc_object_t * );
43 static void Close ( vlc_object_t * );
44 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
47 static int OpenFilter ( vlc_object_t * );
48 static void CloseFilter( vlc_object_t * );
49 static block_t *Resample( filter_t *, block_t * );
51 /*****************************************************************************
53 *****************************************************************************/
56 int32_t *p_prev_sample; /* this filter introduces a 1 sample delay */
58 unsigned int i_remainder; /* remainder of previous sample */
63 /*****************************************************************************
65 *****************************************************************************/
67 set_description( N_("Audio filter for linear interpolation resampling") )
68 set_category( CAT_AUDIO )
69 set_subcategory( SUBCAT_AUDIO_MISC )
70 set_capability( "audio filter", 5 )
71 set_callbacks( Create, Close )
74 set_description( N_("Audio filter for linear interpolation resampling") )
75 set_capability( "audio filter2", 5 )
76 set_callbacks( OpenFilter, CloseFilter )
79 /*****************************************************************************
80 * Create: allocate linear resampler
81 *****************************************************************************/
82 static int Create( vlc_object_t *p_this )
84 aout_filter_t * p_filter = (aout_filter_t *)p_this;
85 struct filter_sys_t * p_sys;
87 if ( p_filter->input.i_rate == p_filter->output.i_rate
88 || p_filter->input.i_format != p_filter->output.i_format
89 || p_filter->input.i_physical_channels
90 != p_filter->output.i_physical_channels
91 || p_filter->input.i_original_channels
92 != p_filter->output.i_original_channels
93 || p_filter->input.i_format != VLC_CODEC_FL32 )
98 /* Allocate the memory needed to store the module's structure */
99 p_sys = malloc( sizeof(filter_sys_t) );
100 p_filter->p_sys = (struct aout_filter_sys_t *)p_sys;
103 p_sys->p_prev_sample = malloc(
104 p_filter->input.i_channels * sizeof(int32_t) );
105 if( p_sys->p_prev_sample == NULL )
110 date_Init( &p_sys->end_date, p_filter->output.i_rate, 1 );
112 p_filter->pf_do_work = DoWork;
114 /* We don't want a new buffer to be created because we're not sure we'll
115 * actually need to resample anything. */
116 p_filter->b_in_place = true;
121 /*****************************************************************************
122 * Close: free our resources
123 *****************************************************************************/
124 static void Close( vlc_object_t * p_this )
126 aout_filter_t * p_filter = (aout_filter_t *)p_this;
127 filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
129 free( p_sys->p_prev_sample );
133 /*****************************************************************************
134 * DoWork: convert a buffer
135 *****************************************************************************/
136 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
137 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
139 filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
140 float *p_out = (float *)p_out_buf->p_buffer;
141 float *p_prev_sample = (float *)p_sys->p_prev_sample;
143 int i_nb_channels = p_filter->input.i_channels;
144 int i_in_nb = p_in_buf->i_nb_samples;
145 int i_chan, i_in, i_out = 0;
147 /* Check if we really need to run the resampler */
148 if( p_aout->mixer_format.i_rate == p_filter->input.i_rate )
150 if( p_filter->b_continuity &&
152 p_in_buf->i_nb_bytes + sizeof(float) * i_nb_channels )
154 /* output the whole thing with the last sample from last time */
155 memmove( ((float *)(p_in_buf->p_buffer)) + i_nb_channels,
156 p_in_buf->p_buffer, p_in_buf->i_nb_bytes );
157 memcpy( p_in_buf->p_buffer, p_prev_sample,
158 i_nb_channels * sizeof(float) );
160 p_filter->b_continuity = false;
164 float p_in_orig[p_in_buf->i_nb_bytes / 4], *p_in = p_in_orig;
166 vlc_memcpy( p_in, p_in_buf->p_buffer, p_in_buf->i_nb_bytes );
168 /* Take care of the previous input sample (if any) */
169 if( !p_filter->b_continuity )
171 p_filter->b_continuity = true;
172 p_sys->i_remainder = 0;
173 date_Init( &p_sys->end_date, p_filter->output.i_rate, 1 );
177 while( p_sys->i_remainder < p_filter->output.i_rate )
179 for( i_chan = i_nb_channels ; i_chan ; )
182 p_out[i_chan] = p_prev_sample[i_chan];
183 p_out[i_chan] += ( ( p_in[i_chan] - p_prev_sample[i_chan] )
185 / p_filter->output.i_rate );
187 p_out += i_nb_channels;
190 p_sys->i_remainder += p_filter->input.i_rate;
192 p_sys->i_remainder -= p_filter->output.i_rate;
195 /* Take care of the current input samples (minus last one) */
196 for( i_in = 0; i_in < i_in_nb - 1; i_in++ )
198 while( p_sys->i_remainder < p_filter->output.i_rate )
200 for( i_chan = i_nb_channels ; i_chan ; )
203 p_out[i_chan] = p_in[i_chan];
204 p_out[i_chan] += ( ( p_in[i_chan + i_nb_channels]
206 * p_sys->i_remainder / p_filter->output.i_rate );
208 p_out += i_nb_channels;
211 p_sys->i_remainder += p_filter->input.i_rate;
214 p_in += i_nb_channels;
215 p_sys->i_remainder -= p_filter->output.i_rate;
218 /* Backup the last input sample for next time */
219 for( i_chan = i_nb_channels ; i_chan ; )
222 p_prev_sample[i_chan] = p_in[i_chan];
225 p_out_buf->i_nb_samples = i_out;
226 p_out_buf->i_pts = p_in_buf->i_pts;
228 if( p_in_buf->i_pts !=
229 date_Get( &p_sys->end_date ) )
231 date_Set( &p_sys->end_date, p_in_buf->i_pts );
234 p_out_buf->end_date = date_Increment( &p_sys->end_date,
235 p_out_buf->i_nb_samples );
237 p_out_buf->i_nb_bytes = p_out_buf->i_nb_samples *
238 i_nb_channels * sizeof(int32_t);
241 /*****************************************************************************
243 *****************************************************************************/
244 static int OpenFilter( vlc_object_t *p_this )
246 filter_t *p_filter = (filter_t *)p_this;
248 int i_out_rate = p_filter->fmt_out.audio.i_rate;
250 if( p_filter->fmt_in.audio.i_rate == p_filter->fmt_out.audio.i_rate ||
251 p_filter->fmt_in.i_codec != VLC_CODEC_FL32 )
256 /* Allocate the memory needed to store the module's structure */
257 p_filter->p_sys = p_sys = malloc( sizeof(struct filter_sys_t) );
261 p_sys->p_prev_sample = malloc(
262 p_filter->fmt_in.audio.i_channels * sizeof(int32_t) );
263 if( p_sys->p_prev_sample == NULL )
268 date_Init( &p_sys->end_date, p_filter->fmt_in.audio.i_rate, 1 );
270 p_filter->pf_audio_filter = Resample;
272 msg_Dbg( p_this, "%4.4s/%iKHz/%i->%4.4s/%iKHz/%i",
273 (char *)&p_filter->fmt_in.i_codec,
274 p_filter->fmt_in.audio.i_rate,
275 p_filter->fmt_in.audio.i_channels,
276 (char *)&p_filter->fmt_out.i_codec,
277 p_filter->fmt_out.audio.i_rate,
278 p_filter->fmt_out.audio.i_channels);
280 p_filter->fmt_out = p_filter->fmt_in;
281 p_filter->fmt_out.audio.i_rate = i_out_rate;
286 /*****************************************************************************
287 * CloseFilter : deallocate data structures
288 *****************************************************************************/
289 static void CloseFilter( vlc_object_t *p_this )
291 filter_t *p_filter = (filter_t *)p_this;
292 free( p_filter->p_sys->p_prev_sample );
293 free( p_filter->p_sys );
296 /*****************************************************************************
298 *****************************************************************************/
299 static block_t *Resample( filter_t *p_filter, block_t *p_block )
301 aout_filter_t aout_filter;
302 aout_buffer_t in_buf, out_buf;
305 int i_bytes_per_frame;
307 if( !p_block || !p_block->i_samples )
310 block_Release( p_block );
314 i_bytes_per_frame = p_filter->fmt_out.audio.i_channels *
315 p_filter->fmt_out.audio.i_bitspersample / 8;
317 i_out_size = i_bytes_per_frame * ( 1 + (p_block->i_samples *
318 p_filter->fmt_out.audio.i_rate / p_filter->fmt_in.audio.i_rate));
320 p_out = p_filter->pf_audio_buffer_new( p_filter, i_out_size );
323 msg_Warn( p_filter, "can't get output buffer" );
324 block_Release( p_block );
328 p_out->i_samples = i_out_size / i_bytes_per_frame;
329 p_out->i_dts = p_block->i_dts;
330 p_out->i_pts = p_block->i_pts;
331 p_out->i_length = p_block->i_length;
333 aout_filter.p_sys = (struct aout_filter_sys_t *)p_filter->p_sys;
334 aout_filter.input = p_filter->fmt_in.audio;
335 aout_filter.output = p_filter->fmt_out.audio;
336 aout_filter.b_continuity = false;
338 in_buf.p_buffer = p_block->p_buffer;
339 in_buf.i_nb_bytes = p_block->i_buffer;
340 in_buf.i_nb_samples = p_block->i_samples;
341 out_buf.p_buffer = p_out->p_buffer;
342 out_buf.i_nb_bytes = p_out->i_buffer;
343 out_buf.i_nb_samples = p_out->i_samples;
345 DoWork( (aout_instance_t *)p_filter, &aout_filter, &in_buf, &out_buf );
347 block_Release( p_block );
349 p_out->i_buffer = out_buf.i_nb_bytes;
350 p_out->i_samples = out_buf.i_nb_samples;