x86: af_volume: add SSE2-optimized s16 volume scaling

libavfilter/af_volume.c

@@ -213,6 +213,9 @@ static void volume_init(VolumeContext *vol)
         vol->samples_align = 8;
         break;
     }
+
+    if (ARCH_X86)
+        ff_volume_init_x86(vol);
 }
 
 static int config_output(AVFilterLink *outlink)

libavfilter/af_volume.h

@@ -50,4 +50,6 @@ typedef struct VolumeContext {
     int samples_align;
 } VolumeContext;
 
+void ff_volume_init_x86(VolumeContext *vol);
+
 #endif /* AVFILTER_AF_VOLUME_H */

libavfilter/x86/Makefile

@@ -1,4 +1,6 @@
 OBJS-$(CONFIG_GRADFUN_FILTER)                += x86/gradfun.o
+OBJS-$(CONFIG_VOLUME_FILTER)                 += x86/af_volume_init.o
 OBJS-$(CONFIG_YADIF_FILTER)                  += x86/yadif.o
 
 YASM-OBJS-$(CONFIG_HQDN3D_FILTER)            += x86/hqdn3d.o
+YASM-OBJS-$(CONFIG_VOLUME_FILTER)            += x86/af_volume.o

libavfilter/x86/af_volume.asm

@@ -0,0 +1,56 @@
+;*****************************************************************************
+;* x86-optimized functions for volume filter
+;* Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
+;*
+;* This file is part of Libav.
+;*
+;* Libav is free software; you can redistribute it and/or
+;* modify it under the terms of the GNU Lesser General Public
+;* License as published by the Free Software Foundation; either
+;* version 2.1 of the License, or (at your option) any later version.
+;*
+;* Libav is distributed in the hope that it will be useful,
+;* but WITHOUT ANY WARRANTY; without even the implied warranty of
+;* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;* Lesser General Public License for more details.
+;*
+;* You should have received a copy of the GNU Lesser General Public
+;* License along with Libav; if not, write to the Free Software
+;* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;******************************************************************************
+
+%include "libavutil/x86/x86inc.asm"
+
+SECTION_RODATA 32
+
+pw_1:   times 8 dw 1
+pw_128: times 8 dw 128
+
+SECTION_TEXT
+
+;------------------------------------------------------------------------------
+; void ff_scale_samples_s16(uint8_t *dst, const uint8_t *src, int len,
+;                           int volume)
+;------------------------------------------------------------------------------
+
+INIT_XMM sse2
+cglobal scale_samples_s16, 4,4,4, dst, src, len, volume
+    movd        m0, volumem
+    pshuflw     m0, m0, 0
+    punpcklwd   m0, [pw_1]
+    mova        m1, [pw_128]
+    lea       lenq, [lend*2-mmsize]
+.loop:
+    ; dst[i] = av_clip_int16((src[i] * volume + 128) >> 8);
+    mova        m2, [srcq+lenq]
+    punpcklwd   m3, m2, m1
+    punpckhwd   m2, m1
+    pmaddwd     m3, m0
+    pmaddwd     m2, m0
+    psrad       m3, 8
+    psrad       m2, 8
+    packssdw    m3, m2
+    mova  [dstq+lenq], m3
+    sub       lenq, mmsize
+    jge .loop
+    REP_RET

libavfilter/x86/af_volume_init.c

@@ -0,0 +1,39 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "libavutil/cpu.h"
+#include "libavutil/samplefmt.h"
+#include "libavutil/x86/cpu.h"
+#include "libavfilter/af_volume.h"
+
+void ff_scale_samples_s16_sse2(uint8_t *dst, const uint8_t *src, int len,
+                               int volume);
+
+void ff_volume_init_x86(VolumeContext *vol)
+{
+    int mm_flags = av_get_cpu_flags();
+    enum AVSampleFormat sample_fmt = av_get_packed_sample_fmt(vol->sample_fmt);
+
+    if (sample_fmt == AV_SAMPLE_FMT_S16) {
+        if (EXTERNAL_SSE2(mm_flags) && vol->volume_i < 32768) {
+            vol->scale_samples = ff_scale_samples_s16_sse2;
+            vol->samples_align = 8;
+        }
+    }
+}