From fe06d5533f8085d685456c99cb1872c64c19f02e Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Fri, 12 Sep 2025 18:23:14 +0200
Subject: [PATCH] swresample/x86/rematrix_init: Avoid allocation for
 native_simd_one

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libswresample/rematrix.c            |  1 -
 libswresample/swresample.c          |  2 +-
 libswresample/swresample_internal.h |  5 ++++-
 libswresample/x86/rematrix_init.c   | 12 +++++-------
 4 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/libswresample/rematrix.c b/libswresample/rematrix.c
index 906f6e0f34..76681e9229 100644
--- a/libswresample/rematrix.c
+++ b/libswresample/rematrix.c
@@ -562,7 +562,6 @@ av_cold int swri_rematrix_init(SwrContext *s){
 av_cold void swri_rematrix_free(SwrContext *s){
     av_freep(&s->native_matrix);
     av_freep(&s->native_simd_matrix);
-    av_freep(&s->native_simd_one);
 }
 
 int swri_rematrix(SwrContext *s, AudioData *out, AudioData *in, int len, int mustcopy){
diff --git a/libswresample/swresample.c b/libswresample/swresample.c
index 67fb7964b2..998ee7b73a 100644
--- a/libswresample/swresample.c
+++ b/libswresample/swresample.c
@@ -688,7 +688,7 @@ static int swr_convert_internal(struct SwrContext *s, AudioData *out, int out_co
 
                     if(len1)
                         for(ch=0; ch<preout->ch_count; ch++)
-                            s->mix_2_1_simd(conv_src->ch[ch], preout->ch[ch], s->dither.noise.ch[ch] + s->dither.noise.bps * s->dither.noise_pos, s->native_simd_one, 0, 0, len1);
+                            s->mix_2_1_simd(conv_src->ch[ch], preout->ch[ch], s->dither.noise.ch[ch] + s->dither.noise.bps * s->dither.noise_pos, &s->native_simd_one, 0, 0, len1);
                     if(out_count != len1)
                         for(ch=0; ch<preout->ch_count; ch++)
                             s->mix_2_1_f(conv_src->ch[ch] + off, preout->ch[ch] + off, s->dither.noise.ch[ch] + s->dither.noise.bps * s->dither.noise_pos + off, &s->native_one, 0, 0, out_count - len1);
diff --git a/libswresample/swresample_internal.h b/libswresample/swresample_internal.h
index 1c889272c8..b016ba3315 100644
--- a/libswresample/swresample_internal.h
+++ b/libswresample/swresample_internal.h
@@ -179,7 +179,10 @@ struct SwrContext {
         double d;
     } native_one;
     uint8_t *native_matrix;
-    uint8_t *native_simd_one;
+    union {
+        int16_t i16[2];
+        float   f;
+    } native_simd_one;
     uint8_t *native_simd_matrix;
     uint8_t matrix_ch[SWR_CH_MAX][SWR_CH_MAX+1];    ///< Lists of input channels per output channel that have non zero rematrixing coefficients
     mix_1_1_func_type *mix_1_1_f;
diff --git a/libswresample/x86/rematrix_init.c b/libswresample/x86/rematrix_init.c
index 5d2c7d9a37..89ec362d62 100644
--- a/libswresample/x86/rematrix_init.c
+++ b/libswresample/x86/rematrix_init.c
@@ -48,8 +48,7 @@ av_cold int swri_rematrix_init_x86(struct SwrContext *s){
             s->mix_2_1_simd = ff_mix_2_1_a_int16_sse2;
         }
         s->native_simd_matrix = av_calloc(num,  2 * sizeof(int16_t));
-        s->native_simd_one    = av_mallocz(2 * sizeof(int16_t));
-        if (!s->native_simd_matrix || !s->native_simd_one)
+        if (!s->native_simd_matrix)
             return AVERROR(ENOMEM);
 
         for(i=0; i<nb_out; i++){
@@ -63,8 +62,8 @@ av_cold int swri_rematrix_init_x86(struct SwrContext *s){
                     ((((int*)s->native_matrix)[i * nb_in + j]) + (1<<sh>>1)) >> sh;
             }
         }
-        ((int16_t*)s->native_simd_one)[1] = 14;
-        ((int16_t*)s->native_simd_one)[0] = 16384;
+        s->native_simd_one.i16[1] = 14;
+        s->native_simd_one.i16[0] = 16384;
     } else if(s->midbuf.fmt == AV_SAMPLE_FMT_FLTP){
         if(EXTERNAL_SSE(mm_flags)) {
             s->mix_1_1_simd = ff_mix_1_1_a_float_sse;
@@ -75,11 +74,10 @@ av_cold int swri_rematrix_init_x86(struct SwrContext *s){
             s->mix_2_1_simd = ff_mix_2_1_a_float_avx;
         }
         s->native_simd_matrix = av_calloc(num, sizeof(float));
-        s->native_simd_one = av_mallocz(sizeof(float));
-        if (!s->native_simd_matrix || !s->native_simd_one)
+        if (!s->native_simd_matrix)
             return AVERROR(ENOMEM);
         memcpy(s->native_simd_matrix, s->native_matrix, num * sizeof(float));
-        memcpy(s->native_simd_one, &s->native_one.f, sizeof(float));
+        s->native_simd_one.f = s->native_one.f;
     }
 #endif