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 *****************************************************************************/
37 /*****************************************************************************
39 *****************************************************************************/
40 static int Create_F32ToS16 ( vlc_object_t * );
41 static void Do_F32ToS16( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
44 static int Create_S16ToF32 ( vlc_object_t * );
45 static void Do_S16ToF32( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
48 static int Create_U8ToF32 ( vlc_object_t * );
49 static void Do_U8ToF32( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
52 /*****************************************************************************
54 *****************************************************************************/
56 set_description( _("Fixed point audio format conversions") );
58 set_callbacks( Create_F32ToS16, NULL );
59 set_capability( "audio filter", 10 );
61 set_callbacks( Create_S16ToF32, NULL );
62 set_capability( "audio filter", 15 );
64 set_callbacks( Create_U8ToF32, NULL );
65 set_capability( "audio filter", 1 );
68 /*****************************************************************************
70 *****************************************************************************/
71 static int Create_F32ToS16( vlc_object_t *p_this )
73 aout_filter_t * p_filter = (aout_filter_t *)p_this;
75 if ( p_filter->input.i_format != VLC_FOURCC('f','i','3','2')
76 || p_filter->output.i_format != AOUT_FMT_S16_NE )
81 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
86 p_filter->pf_do_work = Do_F32ToS16;
87 p_filter->b_in_place = 1;
92 /*****************************************************************************
93 * support routines borrowed from mpg321 (file: mad.c), which is distributed
96 * mpg321 was written by Joe Drew <drew@debian.org>, and based upon 'plaympeg'
97 * from the smpeg sources, which was written by various people from Loki Software
98 * (http://www.lokigames.com).
100 * It also incorporates some source from mad, written by Robert Leslie
101 *****************************************************************************/
103 /* The following two routines and data structure are from the ever-brilliant
107 #define VLC_F_FRACBITS 28
109 # if VLC_F_FRACBITS == 28
110 # define VLC_F(x) ((vlc_fixed_t) (x##L))
113 # define VLC_F_ONE VLC_F(0x10000000)
115 /*****************************************************************************
116 * s24_to_s16_pcm: Scale a 24 bit pcm sample to a 16 bit pcm sample.
117 *****************************************************************************/
118 static inline int16_t s24_to_s16_pcm(vlc_fixed_t sample)
121 sample += (1L << (VLC_F_FRACBITS - 16));
124 if (sample >= VLC_F_ONE)
125 sample = VLC_F_ONE - 1;
126 else if (sample < -VLC_F_ONE)
130 return (sample >> (VLC_F_FRACBITS + 1 - 16));
133 static void Do_F32ToS16( aout_instance_t * p_aout, aout_filter_t * p_filter,
134 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
138 vlc_fixed_t * p_in = (vlc_fixed_t *)p_in_buf->p_buffer;
139 int16_t * p_out = (int16_t *)p_out_buf->p_buffer;
141 for ( i = p_in_buf->i_nb_samples
142 * aout_FormatNbChannels( &p_filter->input ) ; i-- ; )
145 *p_out++ = s24_to_s16_pcm(*p_in++);
147 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
148 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes / 2;
152 /*****************************************************************************
154 *****************************************************************************/
155 static int Create_S16ToF32( vlc_object_t *p_this )
157 aout_filter_t * p_filter = (aout_filter_t *)p_this;
159 if ( p_filter->output.i_format != VLC_FOURCC('f','i','3','2')
160 || p_filter->input.i_format != AOUT_FMT_S16_NE )
165 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
170 p_filter->pf_do_work = Do_S16ToF32;
171 p_filter->b_in_place = 1;
176 static void Do_S16ToF32( aout_instance_t * p_aout, aout_filter_t * p_filter,
177 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
180 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->input );
182 /* We start from the end because b_in_place is true */
183 int16_t * p_in = (int16_t *)p_in_buf->p_buffer + i - 1;
184 vlc_fixed_t * p_out = (vlc_fixed_t *)p_out_buf->p_buffer + i - 1;
188 *p_out = (vlc_fixed_t)( (int32_t)(*p_in) * (FIXED32_ONE >> 16) );
192 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
193 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes
194 * sizeof(vlc_fixed_t) / sizeof(int16_t);
198 /*****************************************************************************
200 *****************************************************************************/
201 static int Create_U8ToF32( vlc_object_t *p_this )
203 aout_filter_t * p_filter = (aout_filter_t *)p_this;
205 if ( p_filter->input.i_format != VLC_FOURCC('u','8',' ',' ')
206 || p_filter->output.i_format != VLC_FOURCC('f','i','3','2') )
211 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
216 p_filter->pf_do_work = Do_U8ToF32;
217 p_filter->b_in_place = true;
222 static void Do_U8ToF32( aout_instance_t * p_aout, aout_filter_t * p_filter,
223 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
226 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->input );
228 /* We start from the end because b_in_place is true */
229 uint8_t * p_in = (uint8_t *)p_in_buf->p_buffer + i - 1;
230 vlc_fixed_t * p_out = (vlc_fixed_t *)p_out_buf->p_buffer + i - 1;
234 *p_out = (vlc_fixed_t)( (int32_t)(*p_in - 128) * (FIXED32_ONE / 128) );
238 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
239 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes * sizeof(vlc_fixed_t);