Re: [FFmpeg-devel] [PATCH v3] avcodec/riscv: add h264 dc idct rvv

["Rémi Denis-Courmont" <remi@remlab.net>]

Le 15 juillet 2024 08:50:38 GMT+03:00, "J. Dekker" <jdek@itanimul.li> a écrit :
>checkasm: bench runs 131072 (1 << 17)
>h264_idct4_add_dc_8bpp_c: 1.5
>h264_idct4_add_dc_8bpp_rvv_i64: 0.7
>h264_idct4_add_dc_9bpp_c: 1.5
>h264_idct4_add_dc_9bpp_rvv_i64: 0.7
>h264_idct4_add_dc_10bpp_c: 1.5
>h264_idct4_add_dc_10bpp_rvv_i64: 0.7
>h264_idct4_add_dc_12bpp_c: 1.2
>h264_idct4_add_dc_12bpp_rvv_i64: 0.7
>h264_idct4_add_dc_14bpp_c: 1.2
>h264_idct4_add_dc_14bpp_rvv_i64: 0.7
>h264_idct8_add_dc_8bpp_c: 5.2
>h264_idct8_add_dc_8bpp_rvv_i64: 1.5
>h264_idct8_add_dc_9bpp_c: 5.5
>h264_idct8_add_dc_9bpp_rvv_i64: 1.2
>h264_idct8_add_dc_10bpp_c: 5.5
>h264_idct8_add_dc_10bpp_rvv_i64: 1.2
>h264_idct8_add_dc_12bpp_c: 4.2
>h264_idct8_add_dc_12bpp_rvv_i64: 1.2
>h264_idct8_add_dc_14bpp_c: 4.2
>h264_idct8_add_dc_14bpp_rvv_i64: 1.2
>
>Signed-off-by: J. Dekker <jdek@itanimul.li>
>---
> libavcodec/riscv/Makefile       |   1 +
> libavcodec/riscv/h264dsp_init.c |  44 ++++++++++-
> libavcodec/riscv/h264dsp_rvv.S  | 130 ++++++++++++++++++++++++++++++++
> 3 files changed, 172 insertions(+), 3 deletions(-)
> create mode 100644 libavcodec/riscv/h264dsp_rvv.S
>
> As Remi mentioned, high bit-depth 4x4 could be done in the same way as low
> bit-depth. I've left it with the high bit-depth intentionally since this eases
> templating. Use of segments removed and repeated instructions changed to use
> m8.
>
>diff --git a/libavcodec/riscv/Makefile b/libavcodec/riscv/Makefile
>index c180223141..a1510e8c6e 100644
>--- a/libavcodec/riscv/Makefile
>+++ b/libavcodec/riscv/Makefile
>@@ -31,6 +31,7 @@ RVV-OBJS-$(CONFIG_H263DSP) += riscv/h263dsp_rvv.o
> OBJS-$(CONFIG_H264CHROMA) += riscv/h264_chroma_init_riscv.o
> RVV-OBJS-$(CONFIG_H264CHROMA) += riscv/h264_mc_chroma.o
> OBJS-$(CONFIG_H264DSP) += riscv/h264dsp_init.o
>+RVV-OBJS-$(CONFIG_H264DSP) += riscv/h264dsp_rvv.o
> OBJS-$(CONFIG_HUFFYUV_DECODER) += riscv/huffyuvdsp_init.o
> RVV-OBJS-$(CONFIG_HUFFYUV_DECODER) += riscv/huffyuvdsp_rvv.o
> OBJS-$(CONFIG_IDCTDSP) += riscv/idctdsp_init.o
>diff --git a/libavcodec/riscv/h264dsp_init.c b/libavcodec/riscv/h264dsp_init.c
>index dbbf3db400..3256199303 100644
>--- a/libavcodec/riscv/h264dsp_init.c
>+++ b/libavcodec/riscv/h264dsp_init.c
>@@ -1,4 +1,5 @@
> /*
>+ * Copyright (c) 2024 J. Dekker <jdek@itanimul.li>
>  * Copyright © 2024 Rémi Denis-Courmont.
>  *
>  * This file is part of FFmpeg.
>@@ -24,22 +25,59 @@
> 
> #include "libavutil/attributes.h"
> #include "libavutil/cpu.h"
>+#include "libavutil/riscv/cpu.h"
> #include "libavcodec/h264dsp.h"
> 
> extern int ff_startcode_find_candidate_rvb(const uint8_t *, int);
> extern int ff_startcode_find_candidate_rvv(const uint8_t *, int);
>+void ff_h264_idct4_dc_add_8_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct8_dc_add_8_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct4_dc_add_9_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct8_dc_add_9_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct4_dc_add_10_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct8_dc_add_10_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct4_dc_add_12_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct8_dc_add_12_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct4_dc_add_14_rvv(uint8_t *, int16_t *, int);
>+void ff_h264_idct8_dc_add_14_rvv(uint8_t *, int16_t *, int);
> 
>-av_cold void ff_h264dsp_init_riscv(H264DSPContext *dsp, const int bit_depth,
>+av_cold void ff_h264dsp_init_riscv(H264DSPContext *c, const int bit_depth,
>                                    const int chroma_format_idc)
> {
> #if HAVE_RV
>     int flags = av_get_cpu_flags();
> 
>     if (flags & AV_CPU_FLAG_RVB_BASIC)
>-        dsp->startcode_find_candidate = ff_startcode_find_candidate_rvb;
>+        c->startcode_find_candidate = ff_startcode_find_candidate_rvb;
> # if HAVE_RVV
>     if (flags & AV_CPU_FLAG_RVV_I32)
>-        dsp->startcode_find_candidate = ff_startcode_find_candidate_rvv;
>+        c->startcode_find_candidate = ff_startcode_find_candidate_rvv;
> # endif
>+    if (ff_rv_vlen_least(128)) {
>+        switch(bit_depth) {
>+        case 8:
>+            if (flags & AV_CPU_FLAG_RVV_I64) {
>+                c->h264_idct_dc_add  = ff_h264_idct4_dc_add_8_rvv;
>+                c->h264_idct8_dc_add = ff_h264_idct8_dc_add_8_rvv;
>+            }
>+            break;
>+        case 9:
>+            c->h264_idct_dc_add  = ff_h264_idct4_dc_add_9_rvv;
>+            c->h264_idct8_dc_add = ff_h264_idct8_dc_add_9_rvv;
>+            break;
>+        case 10:
>+            c->h264_idct_dc_add  = ff_h264_idct4_dc_add_10_rvv;
>+            c->h264_idct8_dc_add = ff_h264_idct8_dc_add_10_rvv;
>+            break;
>+        case 12:
>+            c->h264_idct_dc_add  = ff_h264_idct4_dc_add_12_rvv;
>+            c->h264_idct8_dc_add = ff_h264_idct8_dc_add_12_rvv;
>+            break;
>+        case 14:
>+            c->h264_idct_dc_add  = ff_h264_idct4_dc_add_14_rvv;
>+            c->h264_idct8_dc_add = ff_h264_idct8_dc_add_14_rvv;
>+            break;
>+       }
>+    }
> #endif
> }
>diff --git a/libavcodec/riscv/h264dsp_rvv.S b/libavcodec/riscv/h264dsp_rvv.S
>new file mode 100644
>index 0000000000..0e6c2e49e9
>--- /dev/null
>+++ b/libavcodec/riscv/h264dsp_rvv.S
>@@ -0,0 +1,130 @@
>+/*
>+ * SPDX-License-Identifier: BSD-2-Clause
>+ *
>+ * Copyright (c) 2024 J. Dekker <jdek@itanimul.li>
>+ *
>+ * Redistribution and use in source and binary forms, with or without
>+ * modification, are permitted provided that the following conditions
>+ * are met:
>+ * 1. Redistributions of source code must retain the above copyright
>+ *    notice, this list of conditions and the following disclaimer.
>+ * 2. Redistributions in binary form must reproduce the above copyright
>+ *    notice, this list of conditions and the following disclaimer in the
>+ *    documentation and/or other materials provided with the distribution.
>+ *
>+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
>+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
>+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
>+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
>+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
>+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
>+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
>+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
>+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
>+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
>+ * POSSIBILITY OF SUCH DAMAGE.
>+ */
>+
>+#include "libavutil/riscv/asm.S"
>+
>+.macro idct_dc_add8 width
>+func ff_h264_idct\width\()_dc_add_8_rvv, zve64x, zba
>+.if \width == 8
>+        vsetivli        zero, \width, e16, m1, ta, ma
>+.else
>+        vsetivli        zero, \width, e16, mf2, ta, ma
>+.endif
>+        lh              a3, 0(a1)
>+        addi            a3, a3, 32
>+        srai            a3, a3, 6
>+        sh              zero, 0(a1)
>+.if \width == 8
>+        vlse64.v        v24, (a0), a2
>+        vsetvli         t0, zero, e16, m8, ta, ma
>+.else
>+        vlse32.v        v24, (a0), a2
>+        vsetvli         t0, zero, e16, m4, ta, ma
>+.endif
>+        vzext.vf2       v0, v24
>+        vadd.vx         v0, v0, a3
>+        vmax.vx         v0, v0, zero
>+.if \width == 8
>+        vsetvli         zero, zero, e8, m4, ta, ma
>+.else
>+        vsetvli         zero, zero, e8, m2, ta, ma
>+.endif
>+        vnclipu.wi      v24, v0, 0
>+        vsetivli        zero, \width, e8, m1, ta, ma

Should work with mf2/mf4, though I'm not sure if it makes any significant performance difference. Or alternatively, `e64, m4/m2` would match the LMUL above, but that is purely cosmetic since SEW is not used here.

No objections but it looks like this needs rebasing.

>+.if \width == 8
>+        vsse64.v        v24, (a0), a2
>+.else
>+        vsse32.v        v24, (a0), a2
>+.endif
>+        ret
>+endfunc
>+.endm
>+
>+idct_dc_add8 4
>+idct_dc_add8 8
>+
>+.macro idct_dc_add width
>+func ff_h264_idct\width\()_dc_add_16_rvv, zve64x, zba
>+        vsetivli        zero, \width, e16, m1, ta, ma
>+        lw              a3, 0(a1)
>+        addi            a3, a3, 32
>+        srai            a3, a3, 6
>+        sw              zero, 0(a1)
>+        add             t4, a0, a2
>+        sh1add          t5, a2, a0
>+        sh1add          t6, a2, t4
>+.if \width == 8
>+        sh2add          t0, a2, a0
>+        sh2add          t1, a2, t4
>+        sh2add          t2, a2, t5
>+        sh2add          t3, a2, t6
>+.endif
>+        vle16.v         v0, (a0)
>+        vle16.v         v1, (t4)
>+        vle16.v         v2, (t5)
>+        vle16.v         v3, (t6)
>+.if \width == 8
>+        vle16.v         v4, (t0)
>+        vle16.v         v5, (t1)
>+        vle16.v         v6, (t2)
>+        vle16.v         v7, (t3)
>+        vsetvli         a6, zero, e16, m8, ta, ma
>+.else
>+        vsetvli         a6, zero, e16, m4, ta, ma
>+.endif
>+        vadd.vx         v0, v0, a3
>+        vmax.vx         v0, v0, zero
>+        vmin.vx         v0, v0, a5
>+        vsetivli        zero, \width, e16, m1, ta, ma
>+        vse16.v         v0, (a0)
>+        vse16.v         v1, (t4)
>+        vse16.v         v2, (t5)
>+        vse16.v         v3, (t6)
>+.if \width == 8
>+        vse16.v         v4, (t0)
>+        vse16.v         v5, (t1)
>+        vse16.v         v6, (t2)
>+        vse16.v         v7, (t3)
>+.endif
>+        ret
>+endfunc
>+.endm
>+
>+idct_dc_add 4
>+idct_dc_add 8
>+
>+.irp depth,9,10,12,14
>+func ff_h264_idct4_dc_add_\depth\()_rvv, zve64x
>+        li              a5, (1 << \depth) - 1
>+        j               ff_h264_idct4_dc_add_16_rvv
>+endfunc
>+
>+func ff_h264_idct8_dc_add_\depth\()_rvv, zve64x
>+        li              a5, (1 << \depth) - 1
>+        j               ff_h264_idct8_dc_add_16_rvv
>+endfunc
>+.endr
>-- 
>2.44.1
>
>_______________________________________________
>ffmpeg-devel mailing list
>ffmpeg-devel@ffmpeg.org
>https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
>To unsubscribe, visit link above, or email
>ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".