[FFmpeg-devel] [PATCH] vf_psnr: sse2 optimizations for sum-squared-error.

[Paul B Mahol]

On 7/12/15, Ronald S. Bultje <rsbultje at gmail.com> wrote:
> The internal line accumulator for 16bit can overflow, so I changed that
> from int to uint64_t in the C code. The matching assembly looks a little
> weird but output looks correct.
>
> (avx2 should be trivial to add later.)
> ---
>  libavfilter/psnr.h             |  33 ++++++++++
>  libavfilter/vf_psnr.c          |  76 ++++++++++------------
>  libavfilter/x86/Makefile       |   2 +
>  libavfilter/x86/vf_psnr.asm    | 139
> +++++++++++++++++++++++++++++++++++++++++
>  libavfilter/x86/vf_psnr_init.c |  39 ++++++++++++
>  5 files changed, 247 insertions(+), 42 deletions(-)
>  create mode 100644 libavfilter/psnr.h
>  create mode 100644 libavfilter/x86/vf_psnr.asm
>  create mode 100644 libavfilter/x86/vf_psnr_init.c
>
> diff --git a/libavfilter/psnr.h b/libavfilter/psnr.h
> new file mode 100644
> index 0000000..efe94da
> --- /dev/null
> +++ b/libavfilter/psnr.h
> @@ -0,0 +1,33 @@
> +/*
> + * Copyright (c) 2015 Ronald S. Bultje <rsbultje at gmail.com>
> + *
> + * 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
> + */
> +
> +#ifndef LIBAVFILTER_PSNR_H
> +#define LIBAVFILTER_PSNR_H
> +
> +#include <stddef.h>
> +#include <stdint.h>
> +
> +typedef struct PSNRDSPContext {
> +    uint64_t (*sse_line)(const uint8_t *buf, const uint8_t *ref, int w);

Besides naming of function sse_line rest LGTM.