[FFmpeg-devel] [PATCH] avcodec: add C xvid IDCT support
Clément Bœsch
u at pkh.me
Mon Aug 11 07:44:25 CEST 2014
On Mon, Aug 11, 2014 at 05:18:32AM +0200, Michael Niedermayer wrote:
> From: Pascal Massimino <pascal.massimino at gmail.com>
>
> Thanks to Pascal Massimino and Michael Militzer for permission to use under LGPL
> Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> ---
> libavcodec/Makefile | 2 +-
> libavcodec/xvid_c_idct.c | 335 ++++++++++++++++++++++++++++++++++++++++++++++
> libavcodec/xvididct.c | 60 +++++++++
> libavcodec/xvididct.h | 2 +
> 4 files changed, 398 insertions(+), 1 deletion(-)
> create mode 100644 libavcodec/xvid_c_idct.c
>
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 6873439..55b7b02 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -325,7 +325,7 @@ OBJS-$(CONFIG_MPEG1VIDEO_DECODER) += mpeg12dec.o mpeg12.o mpeg12data.o
> OBJS-$(CONFIG_MPEG1VIDEO_ENCODER) += mpeg12enc.o mpeg12.o
> OBJS-$(CONFIG_MPEG2VIDEO_DECODER) += mpeg12dec.o mpeg12.o mpeg12data.o
> OBJS-$(CONFIG_MPEG2VIDEO_ENCODER) += mpeg12enc.o mpeg12.o
> -OBJS-$(CONFIG_MPEG4_DECODER) += xvididct.o
> +OBJS-$(CONFIG_MPEG4_DECODER) += xvididct.o xvid_c_idct.o
> OBJS-$(CONFIG_MPL2_DECODER) += mpl2dec.o ass.o
> OBJS-$(CONFIG_MSMPEG4V1_DECODER) += msmpeg4dec.o msmpeg4.o msmpeg4data.o
> OBJS-$(CONFIG_MSMPEG4V2_DECODER) += msmpeg4dec.o msmpeg4.o msmpeg4data.o
> diff --git a/libavcodec/xvid_c_idct.c b/libavcodec/xvid_c_idct.c
> new file mode 100644
> index 0000000..b15fb8e
> --- /dev/null
> +++ b/libavcodec/xvid_c_idct.c
> @@ -0,0 +1,335 @@
> +/*****************************************************************************
> + *
> + * XVID MPEG-4 VIDEO CODEC
> + * - Inverse DCT -
> + *
> + * Copyright (C) 2006-2011 Xvid Solutions GmbH
> + *
> + * 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
> + *
> + * $Id$
> + *
No meaning in FFmpeg/git
> + ****************************************************************************/
> +
> +/*
> + * Authors: Skal
> + *
> + * Walken IDCT
> + * Alternative idct implementations for decoding compatibility
> + *
> + * NOTE: this "C" version is not the original one,
> + * but is modified to yield the same error profile
> + * than the MMX version.
> + *
> + ************************************************************************/
> +
/**
* @file
* Walken IDCT
* Alternative idct implementations for decoding compatibility
*
* @author Skal
* @note this "C" version is not the original one, but is modified to
* yield the same error profile than the MMX version.
*/
> +#include "xvididct.h"
> +
> +
> +#define XVID_DSP_CLIP_255(x) ( ((x)&~255) ? ((-(x)) >> (8*sizeof((x))-1))&0xff : (x) )
Looks unused
> +
> +#define ROW_SHIFT 11
> +#define COL_SHIFT 6
> +
> +// #define FIX(x) (int)((x) * (1<<ROW_SHIFT))
> +#define Rnd0 65536 // 1<<(COL_SHIFT+ROW_SHIFT-1);
> +#define Rnd1 3597 // FIX (1.75683487303);
> +#define Rnd2 2260 // FIX (1.10355339059);
> +#define Rnd3 1203 // FIX (0.587788325588);
> +#define Rnd4 0
> +#define Rnd5 120 // FIX (0.058658283817);
> +#define Rnd6 512 // FIX (0.25);
> +#define Rnd7 512 // FIX (0.25);
> +#undef FIX
Mot defined
> +
> +static const int Tab04[] = { 22725, 21407, 19266, 16384, 12873, 8867, 4520 };
> +static const int Tab17[] = { 31521, 29692, 26722, 22725, 17855, 12299, 6270 };
> +static const int Tab26[] = { 29692, 27969, 25172, 21407, 16819, 11585, 5906 };
> +static const int Tab35[] = { 26722, 25172, 22654, 19266, 15137, 10426, 5315 };
> +
> +static int Idct_Row(short * In, const int * const Tab, int Rnd)
> +{
> + const int C1 = Tab[0];
> + const int C2 = Tab[1];
> + const int C3 = Tab[2];
> + const int C4 = Tab[3];
> + const int C5 = Tab[4];
> + const int C6 = Tab[5];
> + const int C7 = Tab[6];
> +
> + const int Right = In[5]|In[6]|In[7];
> + const int Left = In[1]|In[2]|In[3];
> + if (!(Right | In[4]))
> + {
> + const int K = C4*In[0] + Rnd;
> + if (Left)
> + {
If you could fix the style and indent to match FFmpeg one a little that
would be great.
[...]
> +static void idct_xvid_put(uint8_t *dest, int line_size, int16_t *block)
> +{
> + ff_idct_xvid(block);
> + put_pixels_clamped_c(block, dest, line_size);
> +}
> +
> +static void idct_xvid_add(uint8_t *dest, int line_size, int16_t *block)
> +{
> + ff_idct_xvid(block);
> + add_pixels_clamped_c(block, dest, line_size);
> +}
> +
So the function takes a destination buffer but still destroys the input block?
> av_cold void ff_xvididct_init(IDCTDSPContext *c, AVCodecContext *avctx)
> {
> const unsigned high_bit_depth = avctx->bits_per_raw_sample > 8;
> @@ -31,6 +84,13 @@ av_cold void ff_xvididct_init(IDCTDSPContext *c, AVCodecContext *avctx)
> avctx->idct_algo == FF_IDCT_XVID))
> return;
>
> + if (avctx->idct_algo == FF_IDCT_XVID) {
> + c->idct_put = idct_xvid_put;
> + c->idct_add = idct_xvid_add;
> + c->idct = ff_idct_xvid;
> + c->perm_type = FF_IDCT_PERM_NONE;
> + }
> +
> if (ARCH_X86)
> ff_xvididct_init_x86(c);
>
> diff --git a/libavcodec/xvididct.h b/libavcodec/xvididct.h
> index 6678329..1b95cb7 100644
> --- a/libavcodec/xvididct.h
> +++ b/libavcodec/xvididct.h
> @@ -26,4 +26,6 @@ void ff_xvididct_init(IDCTDSPContext *c, AVCodecContext *avctx);
>
> void ff_xvididct_init_x86(IDCTDSPContext *c);
>
> +void ff_idct_xvid(int16_t *const In);
... looks like misleading const
[...]
--
Clément B.
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