1 /*****************************************************************************
2 * a52tofloat32.c: ATSC A/52 aka AC-3 decoder plugin for VLC.
3 * This plugin makes use of liba52 to decode A/52 audio
4 * (http://liba52.sf.net/).
5 *****************************************************************************
6 * Copyright (C) 2001, 2002 VideoLAN
7 * $Id: a52tofloat32.c,v 1.8 2002/11/21 23:06:08 massiot Exp $
9 * Authors: Gildas Bazin <gbazin@netcourrier.com>
10 * Christophe Massiot <massiot@via.ecp.fr>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
25 *****************************************************************************/
27 /*****************************************************************************
29 *****************************************************************************/
32 #include <stdlib.h> /* malloc(), free() */
33 #include <string.h> /* strdup() */
35 # include <stdint.h> /* int16_t .. */
37 # include <inttypes.h> /* int16_t .. */
44 #ifdef USE_A52DEC_TREE /* liba52 header file */
45 # include "include/a52.h"
47 # include "a52dec/a52.h"
50 #include "audio_output.h"
51 #include "aout_internal.h"
53 /*****************************************************************************
55 *****************************************************************************/
56 static int Create ( vlc_object_t * );
57 static void Destroy ( vlc_object_t * );
58 static void DoWork ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
61 /*****************************************************************************
63 *****************************************************************************/
64 struct aout_filter_sys_t
66 a52_state_t * p_liba52; /* liba52 internal structure */
67 vlc_bool_t b_dynrng; /* see below */
68 int i_flags; /* liba52 flags, see a52dec/doc/liba52.txt */
69 int i_nb_channels; /* number of float32 per sample */
72 /*****************************************************************************
74 *****************************************************************************/
75 #define DYNRNG_TEXT N_("A/52 dynamic range compression")
76 #define DYNRNG_LONGTEXT N_( \
77 "Dynamic range compression makes the loud sounds softer, and the soft " \
78 "sounds louder, so you can more easily listen to the stream in a noisy " \
79 "environment without disturbing anyone. If you disable the dynamic range "\
80 "compression the playback will be more adapted to a movie theater or a " \
84 add_category_hint( N_("Miscellaneous"), NULL );
85 add_bool( "a52-dynrng", 1, NULL, DYNRNG_TEXT, DYNRNG_LONGTEXT );
86 set_description( _("ATSC A/52 aka AC-3 audio decoder module") );
87 set_capability( "audio filter", 100 );
88 set_callbacks( Create, Destroy );
91 /*****************************************************************************
93 *****************************************************************************/
94 static int Create( vlc_object_t * _p_filter )
96 aout_filter_t * p_filter = (aout_filter_t *)_p_filter;
97 struct aout_filter_sys_t * p_sys;
99 if ( p_filter->input.i_format != VLC_FOURCC('a','5','2',' ')
100 || p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
105 if ( p_filter->input.i_rate != p_filter->output.i_rate )
110 /* Allocate the memory needed to store the module's structure */
111 p_sys = p_filter->p_sys = malloc( sizeof(struct aout_filter_sys_t) );
114 msg_Err( p_filter, "out of memory" );
118 p_sys->b_dynrng = config_GetInt( p_filter, "a52-dynrng" );
120 /* We'll do our own downmixing, thanks. */
121 p_sys->i_nb_channels = aout_FormatNbChannels( &p_filter->output );
122 switch ( (p_filter->output.i_physical_channels & AOUT_CHAN_PHYSMASK)
125 case AOUT_CHAN_CENTER:
126 if ( (p_filter->output.i_original_channels & AOUT_CHAN_CENTER)
127 || (p_filter->output.i_original_channels
128 & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
130 p_sys->i_flags = A52_MONO;
132 else if ( p_filter->output.i_original_channels & AOUT_CHAN_LEFT )
134 p_sys->i_flags = A52_CHANNEL1;
138 p_sys->i_flags = A52_CHANNEL2;
142 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT:
143 if ( p_filter->output.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
145 p_sys->i_flags = A52_DOLBY;
147 else if ( p_filter->input.i_original_channels & AOUT_CHAN_DUALMONO )
149 p_sys->i_flags = A52_CHANNEL;
151 else if ( !(p_filter->output.i_original_channels & AOUT_CHAN_RIGHT) )
153 p_sys->i_flags = A52_CHANNEL1;
155 else if ( !(p_filter->output.i_original_channels & AOUT_CHAN_LEFT) )
157 p_sys->i_flags = A52_CHANNEL2;
161 p_sys->i_flags = A52_STEREO;
165 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER:
166 p_sys->i_flags = A52_3F;
169 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER:
170 p_sys->i_flags = A52_2F1R;
173 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
174 | AOUT_CHAN_REARCENTER:
175 p_sys->i_flags = A52_3F1R;
178 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
179 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
180 p_sys->i_flags = A52_2F2R;
183 case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
184 | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
185 p_sys->i_flags = A52_3F2R;
189 msg_Err( p_filter, "unknow sample format !" );
193 if ( p_filter->output.i_physical_channels & AOUT_CHAN_LFE )
195 p_sys->i_flags |= A52_LFE;
197 p_sys->i_flags |= A52_ADJUST_LEVEL;
199 /* Initialize liba52 */
200 p_sys->p_liba52 = a52_init( 0 );
201 if( p_sys->p_liba52 == NULL )
203 msg_Err( p_filter, "unable to initialize liba52" );
207 p_filter->pf_do_work = DoWork;
208 p_filter->b_in_place = 0;
213 /*****************************************************************************
214 * Interleave: helper function to interleave channels
215 *****************************************************************************/
216 static void Interleave( float * p_out, const float * p_in, int i_nb_channels )
218 /* We do not only have to interleave, but also reorder the channels
219 * Channel reordering according to number of output channels of libA52
220 * The reordering needs to be different for different channel configurations
221 * (3F2R, 1F2R etc), so this is only temporary.
222 * The WG-4 order is appropriate for stereo, quadrophonia, and 5.1 surround.
225 * channel liba52 order WG-4 order
233 * The liba52 moves channels to the front if there are unused spaces, so
234 * there is no gap between channels. The translation table says which
235 * channel of the new stream [use the new channel # as index] is taken
236 * from which original channel [use the number from the array to address
237 * the original channel].
240 static const int translation[7][6] =
241 {{ 0, 0, 0, 0, 0, 0 }, /* 0 channels (rarely used) */
242 { 0, 0, 0, 0, 0, 0 }, /* 1 ch */
243 { 0, 1, 0, 0, 0, 0 }, /* 2 */
244 { 1, 2, 0, 0, 0, 0 }, /* 3 */
245 { 1, 3, 2, 0, 0, 0 }, /* 4 */
246 { 1, 3, 4, 2, 0, 0 }, /* 5 */
247 { 1, 3, 4, 5, 2, 0 }}; /* 6 */
250 for ( j = 0; j < i_nb_channels; j++ )
252 for ( i = 0; i < 256; i++ )
254 p_out[i * i_nb_channels + translation[i_nb_channels][j]]
260 /*****************************************************************************
261 * Duplicate: helper function to duplicate a unique channel
262 *****************************************************************************/
263 static void Duplicate( float * p_out, const float * p_in )
267 for ( i = 256; i--; )
275 /*****************************************************************************
276 * DoWork: decode an ATSC A/52 frame.
277 *****************************************************************************/
278 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
279 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
281 struct aout_filter_sys_t * p_sys = p_filter->p_sys;
282 sample_t i_sample_level = 1;
283 int i_flags = p_sys->i_flags;
284 int i_bytes_per_block = 256 * p_sys->i_nb_channels
288 /* Do the actual decoding now. */
289 a52_frame( p_sys->p_liba52, p_in_buf->p_buffer,
290 &i_flags, &i_sample_level, 0 );
292 if ( (i_flags & A52_CHANNEL_MASK) != (p_sys->i_flags & A52_CHANNEL_MASK) )
295 "liba52 couldn't do the requested downmix 0x%x->0x%x",
296 p_sys->i_flags & A52_CHANNEL_MASK,
297 i_flags & A52_CHANNEL_MASK );
299 /* We do not know if the output has the same number of channels
300 * than the input, so die quietly... */
301 memset( p_out_buf->p_buffer, 0, i_bytes_per_block * 6 );
302 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
303 p_out_buf->i_nb_bytes = i_bytes_per_block * 6;
307 if( !p_sys->b_dynrng )
309 a52_dynrng( p_filter->p_sys->p_liba52, NULL, NULL );
312 for ( i = 0; i < 6; i++ )
314 sample_t * p_samples;
316 if( a52_block( p_sys->p_liba52 ) )
318 msg_Warn( p_filter, "a52_block failed for block %d", i );
321 p_samples = a52_samples( p_sys->p_liba52 );
323 if ( ((p_sys->i_flags & A52_CHANNEL_MASK) == A52_CHANNEL1
324 || (p_sys->i_flags & A52_CHANNEL_MASK) == A52_CHANNEL2
325 || (p_sys->i_flags & A52_CHANNEL_MASK) == A52_MONO)
326 && (p_filter->output.i_physical_channels
327 & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
329 Duplicate( (float *)(p_out_buf->p_buffer + i * i_bytes_per_block),
334 /* Interleave the *$£%ù samples. */
335 Interleave( (float *)(p_out_buf->p_buffer + i * i_bytes_per_block),
336 p_samples, p_sys->i_nb_channels );
340 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
341 p_out_buf->i_nb_bytes = i_bytes_per_block * 6;
344 /*****************************************************************************
345 * Destroy : deallocate data structures
346 *****************************************************************************/
347 static void Destroy( vlc_object_t * _p_filter )
349 aout_filter_t * p_filter = (aout_filter_t *)_p_filter;
350 struct aout_filter_sys_t * p_sys = p_filter->p_sys;
352 a52_free( p_sys->p_liba52 );