1 /*****************************************************************************
2 * fixed.c: Fixed-point audio format conversions
3 *****************************************************************************
4 * Copyright (C) 2002, 2006-2009 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>
37 #include <vlc_filter.h>
39 /*****************************************************************************
41 *****************************************************************************/
42 static int Create_F32ToS16 ( vlc_object_t * );
43 static block_t *Do_F32ToS16( filter_t *, block_t * );
45 static int Create_S16ToF32 ( vlc_object_t * );
46 static block_t *Do_S16ToF32( filter_t *, block_t * );
48 static int Create_U8ToF32 ( vlc_object_t * );
49 static block_t *Do_U8ToF32( filter_t *, block_t * );
51 /*****************************************************************************
53 *****************************************************************************/
55 set_description( N_("Fixed point audio format conversions") )
57 set_callbacks( Create_F32ToS16, NULL )
58 set_capability( "audio filter", 10 )
60 set_callbacks( Create_S16ToF32, NULL )
61 set_capability( "audio filter", 15 )
63 set_callbacks( Create_U8ToF32, NULL )
64 set_capability( "audio filter", 1 )
67 /*****************************************************************************
69 *****************************************************************************/
70 static int Create_F32ToS16( vlc_object_t *p_this )
72 filter_t * p_filter = (filter_t *)p_this;
74 if ( p_filter->fmt_in.audio.i_format != VLC_CODEC_FI32
75 || p_filter->fmt_out.audio.i_format != VLC_CODEC_S16N )
80 if ( !AOUT_FMTS_SIMILAR( &p_filter->fmt_in.audio, &p_filter->fmt_out.audio ) )
85 p_filter->pf_audio_filter = Do_F32ToS16;
90 /*****************************************************************************
91 * support routines borrowed from mpg321 (file: mad.c), which is distributed
94 * mpg321 was written by Joe Drew <drew@debian.org>, and based upon 'plaympeg'
95 * from the smpeg sources, which was written by various people from Loki Software
96 * (http://www.lokigames.com).
98 * It also incorporates some source from mad, written by Robert Leslie
99 *****************************************************************************/
101 /* The following two routines and data structure are from the ever-brilliant
105 #define VLC_F_FRACBITS 28
107 # if VLC_F_FRACBITS == 28
108 # define VLC_F(x) ((vlc_fixed_t) (x##L))
111 # define VLC_F_ONE VLC_F(0x10000000)
113 /*****************************************************************************
114 * s24_to_s16_pcm: Scale a 24 bit pcm sample to a 16 bit pcm sample.
115 *****************************************************************************/
116 static inline int16_t s24_to_s16_pcm(vlc_fixed_t sample)
119 sample += (1L << (VLC_F_FRACBITS - 16));
122 if (sample >= VLC_F_ONE)
123 sample = VLC_F_ONE - 1;
124 else if (sample < -VLC_F_ONE)
128 return (sample >> (VLC_F_FRACBITS + 1 - 16));
131 static block_t *Do_F32ToS16( filter_t * p_filter, block_t * p_in_buf )
134 vlc_fixed_t * p_in = (vlc_fixed_t *)p_in_buf->p_buffer;
135 int16_t * p_out = (int16_t *)p_in_buf->p_buffer;
137 for ( i = p_in_buf->i_nb_samples
138 * aout_FormatNbChannels( &p_filter->fmt_in.audio ) ; i-- ; )
141 *p_out++ = s24_to_s16_pcm(*p_in++);
143 p_in_buf->i_buffer /= 2;
148 /*****************************************************************************
150 *****************************************************************************/
151 static int Create_S16ToF32( vlc_object_t *p_this )
153 filter_t * p_filter = (filter_t *)p_this;
155 if ( p_filter->fmt_out.audio.i_format != VLC_CODEC_FI32
156 || p_filter->fmt_in.audio.i_format != VLC_CODEC_S16N )
161 if ( !AOUT_FMTS_SIMILAR( &p_filter->fmt_in.audio, &p_filter->fmt_out.audio ) )
166 p_filter->pf_audio_filter = Do_S16ToF32;
171 static block_t *Do_S16ToF32( filter_t * p_filter, block_t * p_in_buf )
174 p_out_buf = filter_NewAudioBuffer( p_filter, p_in_buf->i_buffer * 2 );
178 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->fmt_in.audio );
179 const int16_t * p_in = (int16_t *)p_in_buf->p_buffer;
180 vlc_fixed_t * p_out = (vlc_fixed_t *)p_out_buf->p_buffer;
184 *p_out = (vlc_fixed_t)( (int32_t)(*p_in) * (FIXED32_ONE >> 16) );
188 p_out_buf->i_pts = p_in_buf->i_pts;
189 p_out_buf->i_length = p_in_buf->i_length;
190 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
192 block_Release( p_in_buf );
197 /*****************************************************************************
199 *****************************************************************************/
200 static int Create_U8ToF32( vlc_object_t *p_this )
202 filter_t * p_filter = (filter_t *)p_this;
204 if ( p_filter->fmt_in.audio.i_format != VLC_CODEC_U8
205 || p_filter->fmt_out.audio.i_format != VLC_CODEC_FI32 )
210 if ( !AOUT_FMTS_SIMILAR( &p_filter->fmt_in.audio, &p_filter->fmt_out.audio ) )
215 p_filter->pf_audio_filter = Do_U8ToF32;
220 static block_t *Do_U8ToF32( filter_t * p_filter, block_t * p_in_buf )
223 p_out_buf = filter_NewAudioBuffer( p_filter, 4 * p_in_buf->i_buffer );
227 int i = p_in_buf->i_nb_samples * aout_FormatNbChannels( &p_filter->fmt_in.audio );
229 uint8_t * p_in = (uint8_t *)p_in_buf->p_buffer;
230 vlc_fixed_t * p_out = (vlc_fixed_t *)p_out_buf->p_buffer;
234 *p_out = (vlc_fixed_t)( (int32_t)(*p_in - 128) * (FIXED32_ONE / 128) );
237 p_out_buf->i_pts = p_in_buf->i_pts;
238 p_out_buf->i_length = p_in_buf->i_length;
239 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
241 block_Release( p_in_buf );