modules/arm_neon/volume.c

   1 /*****************************************************************************
   2  * volume.c : ARM NEON audio volume
   3  *****************************************************************************
   4  * Copyright (C) 2012 Rémi Denis-Courmont
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  19  *****************************************************************************/
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include "config.h"
  23 #endif
  24
  25 #include <assert.h>
  26
  27 #include <vlc_common.h>
  28 #include <vlc_plugin.h>
  29 #include <vlc_cpu.h>
  30 #include <vlc_aout.h>
  31 #include <vlc_aout_volume.h>
  32
  33 static int Probe(vlc_object_t *);
  34
  35 vlc_module_begin()
  36     set_category(CAT_AUDIO)
  37     set_subcategory(SUBCAT_AUDIO_MISC)
  38     set_description(N_("ARM NEON audio volume"))
  39     set_capability("audio volume", 10)
  40     set_callbacks(Probe, NULL)
  41 vlc_module_end()
  42
  43 static void AmplifyFloat(audio_volume_t *, block_t *, float);
  44
  45 static int Probe(vlc_object_t *obj)
  46 {
  47     audio_volume_t *volume = (audio_volume_t *)obj;
  48
  49     if (!vlc_CPU_ARM_NEON())
  50         return VLC_EGENERIC;
  51     if (volume->format == VLC_CODEC_FL32)
  52         volume->amplify = AmplifyFloat;
  53     else
  54         return VLC_EGENERIC;
  55     return VLC_SUCCESS;
  56 }
  57
  58 void amplify_float_arm_neon(float *, const float *, size_t, float) asm("amplify_float_arm_neon");
  59
  60 static void AmplifyFloat(audio_volume_t *volume, block_t *block, float amp)
  61 {
  62     float *buf = (float *)block->p_buffer;
  63     size_t length = block->i_buffer;
  64
  65     if (amp == 1.0)
  66         return;
  67
  68     /* Unaligned header */
  69     assert(((uintptr_t)buf & 3) == 0);
  70     while (unlikely((uintptr_t)buf & 12))
  71     {
  72         *(buf++) *= amp;
  73         length -= 4;
  74     }
  75     /* Unaligned footer */
  76     assert((length & 3) == 0);
  77     while (unlikely(length & 12))
  78     {
  79         length -= 4;
  80         buf[length / 4] *= amp;
  81     }
  82
  83     amplify_float_arm_neon(buf, buf, length, amp);
  84     (void) volume;
  85 }