Le torstaina 20. maaliskuuta 2025, 11.30.01 UTC+2 daichengr...@iscas.ac.cn a
écrit :
> From: daichengrong <daichengr...@iscas.ac.cn>
>
> This patch introduces RVV optimized for conv_flt_to_s16.
> On Banana PI F3, it gets an average improvement of 5% for 20000 SAMPLES.
> ---
> libswresample/audioconvert.c | 2 +
> libswresample/riscv/Makefile | 3 ++
> libswresample/riscv/audio_convert_init.c | 50 ++++++++++++++++++++++++
> libswresample/riscv/audio_convert_rvv.S | 46 ++++++++++++++++++++++
> libswresample/swresample_internal.h | 4 ++
> 5 files changed, 105 insertions(+)
> create mode 100644 libswresample/riscv/Makefile
> create mode 100644 libswresample/riscv/audio_convert_init.c
> create mode 100644 libswresample/riscv/audio_convert_rvv.S
>
> diff --git a/libswresample/audioconvert.c b/libswresample/audioconvert.c
> index 04108fb966..49b56b6b5e 100644
> --- a/libswresample/audioconvert.c
> +++ b/libswresample/audioconvert.c
> @@ -182,6 +182,8 @@ AudioConvert *swri_audio_convert_alloc(enum
> AVSampleFormat out_fmt, swri_audio_convert_init_arm(ctx, out_fmt, in_fmt,
> channels);
> #elif ARCH_AARCH64
> swri_audio_convert_init_aarch64(ctx, out_fmt, in_fmt, channels);
> +#elif ARCH_RISCV
> + swri_audio_convert_init_riscv(ctx, out_fmt, in_fmt, channels);
> #endif
>
> return ctx;
> diff --git a/libswresample/riscv/Makefile b/libswresample/riscv/Makefile
> new file mode 100644
> index 0000000000..01943cec64
> --- /dev/null
> +++ b/libswresample/riscv/Makefile
> @@ -0,0 +1,3 @@
> +OBJS += riscv/audio_convert_init.o
> +
> +RVV-OBJS += riscv/audio_convert_rvv.o
> diff --git a/libswresample/riscv/audio_convert_init.c
> b/libswresample/riscv/audio_convert_init.c new file mode 100644
> index 0000000000..7bea7e6eb4
> --- /dev/null
> +++ b/libswresample/riscv/audio_convert_init.c
> @@ -0,0 +1,50 @@
> +/*
> + * 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/riscv/cpu.h"
> +#include "libavutil/samplefmt.h"
> +#include "libswresample/swresample_internal.h"
> +#include "libswresample/audioconvert.h"
> +
> +void swri_oldapi_conv_flt_to_s16_rvv(int16_t *dst, const float *src, int
> len); +
> +static void conv_flt_to_s16_rvv(uint8_t **dst, const uint8_t **src, int
> len){ + swri_oldapi_conv_flt_to_s16_rvv((int16_t*)*dst, (const
> float*)*src, len); +}
> +
> +av_cold void swri_audio_convert_init_riscv(struct AudioConvert *ac,
> + enum AVSampleFormat out_fmt,
> + enum AVSampleFormat in_fmt,
> + int channels)
> +{
> + int flags = av_get_cpu_flags();
This will cause warnings if !HAVE_RVV. Better to guard the whole function
body.
> +
> + ac->simd_f= NULL;
I don't suppose that this is necessary, otherwise how would it work in the
current code base?
> +
> +#if HAVE_RVV
> + if (flags & AV_CPU_FLAG_RVV_F32) {
> + 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_rvv;
> + }
> +#endif
> +}
> diff --git a/libswresample/riscv/audio_convert_rvv.S
> b/libswresample/riscv/audio_convert_rvv.S new file mode 100644
> index 0000000000..d9d58d6d5e
> --- /dev/null
> +++ b/libswresample/riscv/audio_convert_rvv.S
> @@ -0,0 +1,46 @@
> +/*
> + * Copyright (c) 2025 daichengrong <daichengr...@iscas.ac.cn>
> + *
> + * 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 swri_oldapi_conv_flt_to_s16_rvv, zve32f
> + mv t1, a0
> + mv t2, a1
These moves and the one at the end are unnecessary. Just use the argument
registers directly.
> + #mv t3, a2
> +1: vsetvli a4,a2,e32,m8,ta,ma
Not: we use at least one space between operands.
> + vle32.v v8,(t2)
> + sub a2, a2, a4
> + li t0, (1<<15)
You are computing the same value at each loop iteration.
> + sext.w t0,t0
Isn't this a no-op?
> + fcvt.s.w fa2, t0
Again, same input, same output at every iteration.
> + vfmul.vf v16, v8, fa2
> + vfcvt.x.f.v v8, v16
You need to initialise the round mode before you can do that.
> + vsetvli zero,zero,e16,m4,ta,ma
> + vnclip.wi v16, v8, 0
Isn't VFNCVT more straightforward here?
> + vse16.v v16,(t1)
> + sll a4,a4,0x1
> + add t1, t1, a4
> + sll a4, a4, 0x1
> + add t2, t2, a4
You can advantageously use Zba instructions here.
> + bnez a2, 1b
> + mv a0, t1
> + ret
> +endfunc
> \ No newline at end of file
> diff --git a/libswresample/swresample_internal.h
> b/libswresample/swresample_internal.h index 7e46b16fb2..257f69f6dd 100644
> --- a/libswresample/swresample_internal.h
> +++ b/libswresample/swresample_internal.h
> @@ -216,5 +216,9 @@ void swri_audio_convert_init_x86(struct AudioConvert
> *ac, enum AVSampleFormat out_fmt,
> enum AVSampleFormat in_fmt,
> int channels);
> +void swri_audio_convert_init_riscv(struct AudioConvert *ac,
> + enum AVSampleFormat out_fmt,
> + enum AVSampleFormat in_fmt,
> + int channels);
>
> #endif
--
Rémi Denis-Courmont
Tapiolan uusi kaupunki, Uudenmaan entinen Suomen tasavalta
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