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 *****************************************************************************/
34 #include <vlc_common.h>
35 #include <vlc_plugin.h>
38 /*****************************************************************************
40 *****************************************************************************/
41 static int Create_F32ToS16 ( vlc_object_t * );
42 static void Do_F32ToS16( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
45 static int Create_S16ToF32 ( vlc_object_t * );
46 static void Do_S16ToF32( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
49 static int Create_U8ToF32 ( vlc_object_t * );
50 static void Do_U8ToF32( aout_instance_t *, aout_filter_t *, aout_buffer_t *,
53 /*****************************************************************************
55 *****************************************************************************/
57 set_description( N_("Fixed point audio format conversions") )
59 set_callbacks( Create_F32ToS16, NULL )
60 set_capability( "audio filter", 10 )
62 set_callbacks( Create_S16ToF32, NULL )
63 set_capability( "audio filter", 15 )
65 set_callbacks( Create_U8ToF32, NULL )
66 set_capability( "audio filter", 1 )
69 /*****************************************************************************
71 *****************************************************************************/
72 static int Create_F32ToS16( vlc_object_t *p_this )
74 aout_filter_t * p_filter = (aout_filter_t *)p_this;
76 if ( p_filter->fmt_in.audio.i_format != VLC_CODEC_FI32
77 || p_filter->fmt_out.audio.i_format != VLC_CODEC_S16N )
82 if ( !AOUT_FMTS_SIMILAR( &p_filter->fmt_in.audio, &p_filter->fmt_out.audio ) )
87 p_filter->pf_do_work = Do_F32ToS16;
88 p_filter->b_in_place = 1;
93 /*****************************************************************************
94 * support routines borrowed from mpg321 (file: mad.c), which is distributed
97 * mpg321 was written by Joe Drew <drew@debian.org>, and based upon 'plaympeg'
98 * from the smpeg sources, which was written by various people from Loki Software
99 * (http://www.lokigames.com).
101 * It also incorporates some source from mad, written by Robert Leslie
102 *****************************************************************************/
104 /* The following two routines and data structure are from the ever-brilliant
108 #define VLC_F_FRACBITS 28
110 # if VLC_F_FRACBITS == 28
111 # define VLC_F(x) ((vlc_fixed_t) (x##L))
114 # define VLC_F_ONE VLC_F(0x10000000)
116 /*****************************************************************************
117 * s24_to_s16_pcm: Scale a 24 bit pcm sample to a 16 bit pcm sample.
118 *****************************************************************************/
119 static inline int16_t s24_to_s16_pcm(vlc_fixed_t sample)
122 sample += (1L << (VLC_F_FRACBITS - 16));
125 if (sample >= VLC_F_ONE)
126 sample = VLC_F_ONE - 1;
127 else if (sample < -VLC_F_ONE)
131 return (sample >> (VLC_F_FRACBITS + 1 - 16));
134 static void Do_F32ToS16( aout_instance_t * p_aout, aout_filter_t * p_filter,
135 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
139 vlc_fixed_t * p_in = (vlc_fixed_t *)p_in_buf->p_buffer;
140 int16_t * p_out = (int16_t *)p_out_buf->p_buffer;
142 for ( i = p_in_buf->i_nb_samples
143 * aout_FormatNbChannels( &p_filter->fmt_in.audio ) ; i-- ; )
146 *p_out++ = s24_to_s16_pcm(*p_in++);
148 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
149 p_out_buf->i_buffer = p_in_buf->i_buffer / 2;
153 /*****************************************************************************
155 *****************************************************************************/
156 static int Create_S16ToF32( vlc_object_t *p_this )
158 aout_filter_t * p_filter = (aout_filter_t *)p_this;
160 if ( p_filter->fmt_out.audio.i_format != VLC_CODEC_FI32
161 || p_filter->fmt_in.audio.i_format != VLC_CODEC_S16N )
166 if ( !AOUT_FMTS_SIMILAR( &p_filter->fmt_in.audio, &p_filter->fmt_out.audio ) )
171 p_filter->pf_do_work = Do_S16ToF32;
172 p_filter->b_in_place = 1;
177 static void Do_S16ToF32( aout_instance_t * p_aout, aout_filter_t * p_filter,
178 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
181 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->fmt_in.audio );
183 /* We start from the end because b_in_place is true */
184 int16_t * p_in = (int16_t *)p_in_buf->p_buffer + i - 1;
185 vlc_fixed_t * p_out = (vlc_fixed_t *)p_out_buf->p_buffer + i - 1;
189 *p_out = (vlc_fixed_t)( (int32_t)(*p_in) * (FIXED32_ONE >> 16) );
193 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
194 p_out_buf->i_buffer = p_in_buf->i_buffer
195 * sizeof(vlc_fixed_t) / sizeof(int16_t);
199 /*****************************************************************************
201 *****************************************************************************/
202 static int Create_U8ToF32( vlc_object_t *p_this )
204 aout_filter_t * p_filter = (aout_filter_t *)p_this;
206 if ( p_filter->fmt_in.audio.i_format != VLC_CODEC_U8
207 || p_filter->fmt_out.audio.i_format != VLC_CODEC_FI32 )
212 if ( !AOUT_FMTS_SIMILAR( &p_filter->fmt_in.audio, &p_filter->fmt_out.audio ) )
217 p_filter->pf_do_work = Do_U8ToF32;
218 p_filter->b_in_place = true;
223 static void Do_U8ToF32( aout_instance_t * p_aout, aout_filter_t * p_filter,
224 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
227 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->fmt_in.audio );
229 /* We start from the end because b_in_place is true */
230 uint8_t * p_in = (uint8_t *)p_in_buf->p_buffer + i - 1;
231 vlc_fixed_t * p_out = (vlc_fixed_t *)p_out_buf->p_buffer + i - 1;
235 *p_out = (vlc_fixed_t)( (int32_t)(*p_in - 128) * (FIXED32_ONE / 128) );
239 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
240 p_out_buf->i_buffer = p_in_buf->i_buffer * sizeof(vlc_fixed_t);