lavc/pixblockdsp: RISC-V I get_pixels

Benchmarks on SiFive U74-MC (courtesy of Shanghai StarFive Tech):
get_pixels_c: 180.0
get_pixels_rvi: 136.7

libavcodec/pixblockdsp.c

@@ -109,6 +109,8 @@ av_cold void ff_pixblockdsp_init(PixblockDSPContext *c, AVCodecContext *avctx)
     ff_pixblockdsp_init_arm(c, avctx, high_bit_depth);
 #elif ARCH_PPC
     ff_pixblockdsp_init_ppc(c, avctx, high_bit_depth);
+#elif ARCH_RISCV
+    ff_pixblockdsp_init_riscv(c, avctx, high_bit_depth);
 #elif ARCH_X86
     ff_pixblockdsp_init_x86(c, avctx, high_bit_depth);
 #elif ARCH_MIPS

libavcodec/pixblockdsp.h

@@ -52,6 +52,8 @@ void ff_pixblockdsp_init_arm(PixblockDSPContext *c, AVCodecContext *avctx,
                              unsigned high_bit_depth);
 void ff_pixblockdsp_init_ppc(PixblockDSPContext *c, AVCodecContext *avctx,
                              unsigned high_bit_depth);
+void ff_pixblockdsp_init_riscv(PixblockDSPContext *c, AVCodecContext *avctx,
+                               unsigned high_bit_depth);
 void ff_pixblockdsp_init_x86(PixblockDSPContext *c, AVCodecContext *avctx,
                              unsigned high_bit_depth);
 void ff_pixblockdsp_init_mips(PixblockDSPContext *c, AVCodecContext *avctx,

libavcodec/riscv/Makefile

@@ -1,2 +1,4 @@
 OBJS-$(CONFIG_AUDIODSP) += riscv/audiodsp_init.o \
                            riscv/audiodsp_rvf.o
+OBJS-$(CONFIG_PIXBLOCKDSP) += riscv/pixblockdsp_init.o \
+                              riscv/pixblockdsp_rvi.o

libavcodec/riscv/pixblockdsp_init.c

@@ -0,0 +1,45 @@
+/*
+ * Copyright © 2022 Rémi Denis-Courmont.
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+
+#include "libavutil/attributes.h"
+#include "libavutil/cpu.h"
+#include "libavcodec/avcodec.h"
+#include "libavcodec/pixblockdsp.h"
+
+void ff_get_pixels_8_rvi(int16_t *block, const uint8_t *pixels,
+                         ptrdiff_t stride);
+void ff_get_pixels_16_rvi(int16_t *block, const uint8_t *pixels,
+                          ptrdiff_t stride);
+
+av_cold void ff_pixblockdsp_init_riscv(PixblockDSPContext *c,
+                                       AVCodecContext *avctx,
+                                       unsigned high_bit_depth)
+{
+    int cpu_flags = av_get_cpu_flags();
+
+    if (cpu_flags & AV_CPU_FLAG_RVI) {
+        if (high_bit_depth)
+            c->get_pixels = ff_get_pixels_16_rvi;
+        else
+            c->get_pixels = ff_get_pixels_8_rvi;
+    }
+}

libavcodec/riscv/pixblockdsp_rvi.S

@@ -0,0 +1,59 @@
+/*
+ * Copyright © 2022 Rémi Denis-Courmont.
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "config.h"
+#include "../libavutil/riscv/asm.S"
+
+func ff_get_pixels_8_rvi
+.irp row, 0, 1, 2, 3, 4, 5, 6, 7
+        ld      t0,    (a1)
+        add     a1, a1, a2
+        sd      zero, ((\row * 16) + 0)(a0)
+        addi    t6, t6, -1
+        sd      zero, ((\row * 16) + 8)(a0)
+        srli    t1, t0, 8
+        sb      t0, ((\row * 16) + 0)(a0)
+        srli    t2, t0, 16
+        sb      t1, ((\row * 16) + 2)(a0)
+        srli    t3, t0, 24
+        sb      t2, ((\row * 16) + 4)(a0)
+        srli    t4, t0, 32
+        sb      t3, ((\row * 16) + 6)(a0)
+        srli    t1, t0, 40
+        sb      t4, ((\row * 16) + 8)(a0)
+        srli    t2, t0, 48
+        sb      t1, ((\row * 16) + 10)(a0)
+        srli    t3, t0, 56
+        sb      t2, ((\row * 16) + 12)(a0)
+        sb      t3, ((\row * 16) + 14)(a0)
+.endr
+        ret
+endfunc
+
+func ff_get_pixels_16_rvi
+.irp row, 0, 1, 2, 3, 4, 5, 6, 7
+        ld      t0, 0(a1)
+        ld      t1, 8(a1)
+        add     a1, a1, a2
+        sd      t0, ((\row * 16) + 0)(a0)
+        sd      t1, ((\row * 16) + 8)(a0)
+.endr
+        ret
+endfunc