ARM: libswresample: NEON optimised flat float to s16 conversion

Adapted to swr by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libswresample/arm/Makefile

+OBJS      += arm/audio_convert_init.o
+NEON-OBJS += arm/audio_convert_neon.o

libswresample/arm/audio_convert_init.c

+/*
+ * This file is part of libswresample.
+ *
+ * libswresample 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.
+ *
+ * libswresample 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 libswresample; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+
+#include "config.h"
+#include "libavutil/attributes.h"
+#include "libavutil/cpu.h"
+#include "libavutil/arm/cpu.h"
+#include "libavutil/samplefmt.h"
+#include "libswresample/swresample_internal.h"
+#include "libswresample/audioconvert.h"
+
+void swri_oldapi_conv_flt_to_s16_neon(int16_t *dst, const float *src, int len);
+
+static void conv_flt_to_s16_neon(uint8_t **dst, const uint8_t **src, int len){
+    swri_oldapi_conv_flt_to_s16_neon((int16_t*)*dst, (const float*)*src, len);
+}
+
+av_cold void swri_audio_convert_init_arm(struct AudioConvert *ac,
+                                       enum AVSampleFormat out_fmt,
+                                       enum AVSampleFormat in_fmt,
+                                       int channels)
+{
+    int cpu_flags = av_get_cpu_flags();
+
+    ac->simd_f= NULL;
+
+    if (have_neon(cpu_flags)) {
+        if(out_fmt == AV_SAMPLE_FMT_S16 && in_fmt == AV_SAMPLE_FMT_FLT || out_fmt == AV_SAMPLE_FMT_S16P && in_fmt == AV_SAMPLE_FMT_FLTP)
+            ac->simd_f = conv_flt_to_s16_neon;
+    }
+}

libswresample/arm/audio_convert_neon.S

+/*
+ * Copyright (c) 2008 Mans Rullgard <mans@mansr.com>
+ *
+ * This file is part of libswresample.
+ *
+ * libswresample 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.
+ *
+ * libswresample 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 libswresample; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "libavutil/arm/asm.S"
+
+function swri_oldapi_conv_flt_to_s16_neon, export=1
+        subs            r2,  r2,  #8
+        vld1.32         {q0},     [r1,:128]!
+        vcvt.s32.f32    q8,  q0,  #31
+        vld1.32         {q1},     [r1,:128]!
+        vcvt.s32.f32    q9,  q1,  #31
+        beq             3f
+        bics            r12, r2,  #15
+        beq             2f
+1:      subs            r12, r12, #16
+        vqrshrn.s32     d4,  q8,  #16
+        vld1.32         {q0},     [r1,:128]!
+        vcvt.s32.f32    q0,  q0,  #31
+        vqrshrn.s32     d5,  q9,  #16
+        vld1.32         {q1},     [r1,:128]!
+        vcvt.s32.f32    q1,  q1,  #31
+        vqrshrn.s32     d6,  q0,  #16
+        vst1.16         {q2},     [r0,:128]!
+        vqrshrn.s32     d7,  q1,  #16
+        vld1.32         {q8},     [r1,:128]!
+        vcvt.s32.f32    q8,  q8,  #31
+        vld1.32         {q9},     [r1,:128]!
+        vcvt.s32.f32    q9,  q9,  #31
+        vst1.16         {q3},     [r0,:128]!
+        bne             1b
+        ands            r2,  r2,  #15
+        beq             3f
+2:      vld1.32         {q0},     [r1,:128]!
+        vqrshrn.s32     d4,  q8,  #16
+        vcvt.s32.f32    q0,  q0,  #31
+        vld1.32         {q1},     [r1,:128]!
+        vqrshrn.s32     d5,  q9,  #16
+        vcvt.s32.f32    q1,  q1,  #31
+        vqrshrn.s32     d6,  q0,  #16
+        vst1.16         {q2},     [r0,:128]!
+        vqrshrn.s32     d7,  q1,  #16
+        vst1.16         {q3},     [r0,:128]!
+        bx              lr
+3:      vqrshrn.s32     d4,  q8,  #16
+        vqrshrn.s32     d5,  q9,  #16
+        vst1.16         {q2},     [r0,:128]!
+        bx              lr
+endfunc

libswresample/audioconvert.c

@@ -155,6 +155,7 @@ AudioConvert *swri_audio_convert_alloc(enum AVSampleFormat out_fmt,
     }
 
     if(HAVE_YASM && HAVE_MMX) swri_audio_convert_init_x86(ctx, out_fmt, in_fmt, channels);
+    if(ARCH_ARM)              swri_audio_convert_init_arm(ctx, out_fmt, in_fmt, channels);
 
     return ctx;
 }

libswresample/swresample_internal.h

@@ -131,6 +131,10 @@ void swri_rematrix_init_x86(struct SwrContext *s);
 
 void swri_get_dither(SwrContext *s, void *dst, int len, unsigned seed, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt);
 
+void swri_audio_convert_init_arm(struct AudioConvert *ac,
+                                 enum AVSampleFormat out_fmt,
+                                 enum AVSampleFormat in_fmt,
+                                 int channels);
 void swri_audio_convert_init_x86(struct AudioConvert *ac,
                                  enum AVSampleFormat out_fmt,
                                  enum AVSampleFormat in_fmt,