lavc/idctdsp: RISC-V V put_pixels_clamped function

libavcodec/idctdsp.c

@@ -312,6 +312,8 @@ av_cold void ff_idctdsp_init(IDCTDSPContext *c, AVCodecContext *avctx)
     ff_idctdsp_init_arm(c, avctx, high_bit_depth);
 #elif ARCH_PPC
     ff_idctdsp_init_ppc(c, avctx, high_bit_depth);
+#elif ARCH_RISCV
+    ff_idctdsp_init_riscv(c, avctx, high_bit_depth);
 #elif ARCH_X86
     ff_idctdsp_init_x86(c, avctx, high_bit_depth);
 #elif ARCH_MIPS

libavcodec/idctdsp.h

@@ -114,6 +114,8 @@ void ff_idctdsp_init_arm(IDCTDSPContext *c, AVCodecContext *avctx,
                          unsigned high_bit_depth);
 void ff_idctdsp_init_ppc(IDCTDSPContext *c, AVCodecContext *avctx,
                          unsigned high_bit_depth);
+void ff_idctdsp_init_riscv(IDCTDSPContext *c, AVCodecContext *avctx,
+                           unsigned high_bit_depth);
 void ff_idctdsp_init_x86(IDCTDSPContext *c, AVCodecContext *avctx,
                          unsigned high_bit_depth);
 void ff_idctdsp_init_mips(IDCTDSPContext *c, AVCodecContext *avctx,

libavcodec/riscv/Makefile

@@ -5,6 +5,8 @@ OBJS-$(CONFIG_AUDIODSP) += riscv/audiodsp_init.o \
 RVV-OBJS-$(CONFIG_AUDIODSP) += riscv/audiodsp_rvv.o
 OBJS-$(CONFIG_FMTCONVERT) += riscv/fmtconvert_init.o
 RVV-OBJS-$(CONFIG_FMTCONVERT) += riscv/fmtconvert_rvv.o
+OBJS-$(CONFIG_IDCTDSP) += riscv/idctdsp_init.o
+RVV-OBJS-$(CONFIG_IDCTDSP) += riscv/idctdsp_rvv.o
 OBJS-$(CONFIG_PIXBLOCKDSP) += riscv/pixblockdsp_init.o \
                               riscv/pixblockdsp_rvi.o
 OBJS-$(CONFIG_VORBIS_DECODER) += riscv/vorbisdsp_init.o

libavcodec/riscv/idctdsp_init.c

@@ -0,0 +1,41 @@
+/*
+ * 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 "libavutil/riscv/cpu.h"
+#include "libavcodec/avcodec.h"
+#include "libavcodec/idctdsp.h"
+
+void ff_put_pixels_clamped_rvv(const int16_t *block, uint8_t *pixels,
+                               ptrdiff_t stride);
+
+av_cold void ff_idctdsp_init_riscv(IDCTDSPContext *c, AVCodecContext *avctx,
+                                   unsigned high_bit_depth)
+{
+#if HAVE_RVV
+    int flags = av_get_cpu_flags();
+
+    if ((flags & AV_CPU_FLAG_RVV_I32) && ff_get_rv_vlenb() >= 16)
+        c->put_pixels_clamped = ff_put_pixels_clamped_rvv;
+#endif
+}

libavcodec/riscv/idctdsp_rvv.S

@@ -0,0 +1,43 @@
+/*
+ * 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_put_pixels_clamped_rvv, zve32x
+        vsetivli    zero, 8, e16, m1, ta, ma
+        vlseg8e16.v v24, (a0)
+        /* RVV only has signed-signed and unsigned-unsigned clipping.
+         * We need two steps for signed-to-unsigned clipping. */
+        vsetvli     t0, zero, e16, m8, ta, ma
+        vmax.vx     v24, v24, zero
+
+        vsetivli    zero, 8, e8, mf2, ta, ma
+        vnclipu.wi  v16, v24, 0
+        vnclipu.wi  v17, v25, 0
+        vnclipu.wi  v18, v26, 0
+        vnclipu.wi  v19, v27, 0
+        vnclipu.wi  v20, v28, 0
+        vnclipu.wi  v21, v29, 0
+        vnclipu.wi  v22, v30, 0
+        vnclipu.wi  v23, v31, 0
+        vssseg8e8.v v16, (a1), a2
+        ret
+endfunc