1 /*****************************************************************************
2 * fixed.c: Fixed-point audio format conversions
3 *****************************************************************************
4 * Copyright (C) 2002, 2006 the VideoLAN team
7 * Authors: Jean-Paul Saman <jpsaman _at_ videolan _dot_ org>
8 * Marc Ariberti <marcari@videolan.org>
9 * Samuel Hocevar <sam@zoy.org>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
24 *****************************************************************************/
26 /*****************************************************************************
28 *****************************************************************************/
33 /*****************************************************************************
35 *****************************************************************************/
36 static int Create_F32ToS16 ( vlc_object_t * );
37 static void Do_F32ToS16( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
40 static int Create_S16ToF32 ( vlc_object_t * );
41 static void Do_S16ToF32( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
44 static int Create_U8ToF32 ( vlc_object_t * );
45 static void Do_U8ToF32( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
48 /*****************************************************************************
50 *****************************************************************************/
52 set_description( _("Fixed point audio format conversions") );
54 set_callbacks( Create_F32ToS16, NULL );
55 set_capability( "audio filter", 10 );
57 set_callbacks( Create_S16ToF32, NULL );
58 set_capability( "audio filter", 15 );
60 set_callbacks( Create_U8ToF32, NULL );
61 set_capability( "audio filter", 1 );
64 /*****************************************************************************
66 *****************************************************************************/
67 static int Create_F32ToS16( vlc_object_t *p_this )
69 aout_filter_t * p_filter = (aout_filter_t *)p_this;
71 if ( p_filter->input.i_format != VLC_FOURCC('f','i','3','2')
72 || p_filter->output.i_format != AOUT_FMT_S16_NE )
77 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
82 p_filter->pf_do_work = Do_F32ToS16;
83 p_filter->b_in_place = 1;
88 /*****************************************************************************
89 * support routines borrowed from mpg321 (file: mad.c), which is distributed
92 * mpg321 was written by Joe Drew <drew@debian.org>, and based upon 'plaympeg'
93 * from the smpeg sources, which was written by various people from Loki Software
94 * (http://www.lokigames.com).
96 * It also incorporates some source from mad, written by Robert Leslie
97 *****************************************************************************/
99 /* The following two routines and data structure are from the ever-brilliant
103 #define VLC_F_FRACBITS 28
105 # if VLC_F_FRACBITS == 28
106 # define VLC_F(x) ((vlc_fixed_t) (x##L))
109 # define VLC_F_ONE VLC_F(0x10000000)
111 /*****************************************************************************
112 * s24_to_s16_pcm: Scale a 24 bit pcm sample to a 16 bit pcm sample.
113 *****************************************************************************/
114 static inline int16_t s24_to_s16_pcm(vlc_fixed_t sample)
117 sample += (1L << (VLC_F_FRACBITS - 16));
120 if (sample >= VLC_F_ONE)
121 sample = VLC_F_ONE - 1;
122 else if (sample < -VLC_F_ONE)
126 return (sample >> (VLC_F_FRACBITS + 1 - 16));
129 static void Do_F32ToS16( aout_instance_t * p_aout, aout_filter_t * p_filter,
130 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
133 vlc_fixed_t * p_in = (vlc_fixed_t *)p_in_buf->p_buffer;
134 int16_t * p_out = (int16_t *)p_out_buf->p_buffer;
136 for ( i = p_in_buf->i_nb_samples
137 * aout_FormatNbChannels( &p_filter->input ) ; i-- ; )
140 *p_out++ = s24_to_s16_pcm(*p_in++);
142 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
143 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes / 2;
147 /*****************************************************************************
149 *****************************************************************************/
150 static int Create_S16ToF32( vlc_object_t *p_this )
152 aout_filter_t * p_filter = (aout_filter_t *)p_this;
154 if ( p_filter->output.i_format != VLC_FOURCC('f','i','3','2')
155 || p_filter->input.i_format != AOUT_FMT_S16_NE )
160 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
165 p_filter->pf_do_work = Do_S16ToF32;
166 p_filter->b_in_place = 1;
171 static void Do_S16ToF32( aout_instance_t * p_aout, aout_filter_t * p_filter,
172 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
174 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->input );
176 /* We start from the end because b_in_place is true */
177 int16_t * p_in = (int16_t *)p_in_buf->p_buffer + i - 1;
178 vlc_fixed_t * p_out = (vlc_fixed_t *)p_out_buf->p_buffer + i - 1;
182 *p_out = (vlc_fixed_t)( (int32_t)(*p_in) * (FIXED32_ONE >> 16) );
186 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
187 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes
188 * sizeof(vlc_fixed_t) / sizeof(int16_t);
192 /*****************************************************************************
194 *****************************************************************************/
195 static int Create_U8ToF32( vlc_object_t *p_this )
197 aout_filter_t * p_filter = (aout_filter_t *)p_this;
199 if ( p_filter->input.i_format != VLC_FOURCC('u','8',' ',' ')
200 || p_filter->output.i_format != VLC_FOURCC('f','i','3','2') )
205 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
210 p_filter->pf_do_work = Do_U8ToF32;
211 p_filter->b_in_place = VLC_TRUE;
216 static void Do_U8ToF32( aout_instance_t * p_aout, aout_filter_t * p_filter,
217 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
219 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->input );
221 /* We start from the end because b_in_place is true */
222 uint8_t * p_in = (uint8_t *)p_in_buf->p_buffer + i - 1;
223 vlc_fixed_t * p_out = (vlc_fixed_t *)p_out_buf->p_buffer + i - 1;
227 *p_out = (vlc_fixed_t)( (int32_t)(*p_in - 128) * (FIXED32_ONE / 128) );
231 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
232 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * sizeof(vlc_fixed_t);