#include "libavutil/avassert.h"
#include "libavutil/bswap.h"
#include "libavutil/rational.h"
#include "ops.h"
#include "ops_internal.h"

Macros
#define	RET(x)
	Copyright (C) 2025 Niklas Haas. More...

Functions
static bool	op_commute_clear (SwsOp op, SwsOp next)
	Try to commute a clear op with the next operation. More...

static bool	op_commute_swizzle (SwsOp op, SwsOp next)
	Try to commute a swizzle op with the next operation. More...

static unsigned	merge_comp_flags (unsigned a, unsigned b)

void	ff_sws_op_list_update_comps (SwsOpList *ops)
	Infer + propagate known information about components. More...

static int	exact_log2 (const int x)

static int	exact_log2_q (const AVRational x)

static bool	extract_scalar (const SwsLinearOp c, SwsComps prev, SwsComps next, SwsConst out_scale)
	If a linear operation can be reduced to a scalar multiplication, returns the corresponding scaling factor, or 0 otherwise. More...

static bool	extract_constant_rows (SwsLinearOp c, SwsComps prev, SwsConst out_clear)

static bool	extract_swizzle (SwsLinearOp op, SwsComps prev, SwsSwizzleOp out_swiz)

int	ff_sws_op_list_optimize (SwsOpList *ops)
	Fuse compatible and eliminate redundant operations, as well as replacing some operations with more efficient alternatives. More...

int	ff_sws_solve_shuffle (const SwsOpList const ops, uint8_t shuffle[], int size, uint8_t clear_val, int read_bytes, int *write_bytes)
	"Solve" an op list into a fixed shuffle mask, with an optional ability to also directly clear the output value (for e.g. More...

Variables
static const unsigned	flags_identity = SWS_COMP_ZERO \| SWS_COMP_EXACT

Macro Definition Documentation

◆ RET

#define RET ( x )

Value:

    do {                                                                       \
        if ((ret = (x)) < 0)                                                   \
            return ret;                                                        \
    } while (0)

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

Definition at line 28 of file ops_optimizer.c.

Function Documentation

◆ op_commute_clear()

static bool op_commute_clear	(	SwsOp *	op,
		SwsOp *	next
	)

static

Try to commute a clear op with the next operation.

Makes any adjustments to the operations as needed, but does not perform the actual commutation.

Returns whether successful.

Definition at line 40 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

◆ op_commute_swizzle()

static bool op_commute_swizzle	(	SwsOp *	op,
		SwsOp *	next
	)

static

Try to commute a swizzle op with the next operation.

Makes any adjustments to the operations as needed, but does not perform the actual commutation.

Returns whether successful.

We can commute per-channel ops only if the per-channel constants are the same for all duplicated channels; e.g.: SWIZZLE {0, 0, 0, 3} NEXT {x, x, x, w} -> NEXT {x, _, _, w} SWIZZLE {0, 0, 0, 3}

Definition at line 79 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

◆ merge_comp_flags()

static unsigned merge_comp_flags	(	unsigned	a,
		unsigned	b
	)

static

Definition at line 151 of file ops_optimizer.c.

Referenced by ff_sws_op_list_update_comps().

◆ ff_sws_op_list_update_comps()

void ff_sws_op_list_update_comps ( SwsOpList * ops )

Infer + propagate known information about components.

Called automatically when needed by the optimizer and compiler.

Definition at line 159 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

◆ exact_log2()

static int exact_log2 ( const int x )

static

Definition at line 389 of file ops_optimizer.c.

Referenced by exact_log2_q().

◆ exact_log2_q()

static int exact_log2_q ( const AVRational x )

static

Definition at line 398 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

◆ extract_scalar()

static bool extract_scalar	(	const SwsLinearOp *	c,
		SwsComps	prev,
		SwsComps	next,
		SwsConst *	out_scale
	)

static

If a linear operation can be reduced to a scalar multiplication, returns the corresponding scaling factor, or 0 otherwise.

Definition at line 412 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

◆ extract_constant_rows()

static bool extract_constant_rows	(	SwsLinearOp *	c,
		SwsComps	prev,
		SwsConst *	out_clear
	)

static

Definition at line 436 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

◆ extract_swizzle()

static bool extract_swizzle	(	SwsLinearOp *	op,
		SwsComps	prev,
		SwsSwizzleOp *	out_swiz
	)

static

Definition at line 464 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

◆ ff_sws_op_list_optimize()

int ff_sws_op_list_optimize ( SwsOpList * ops )

Fuse compatible and eliminate redundant operations, as well as replacing some operations with more efficient alternatives.

Definition at line 496 of file ops_optimizer.c.

Referenced by run_test().

◆ ff_sws_solve_shuffle()

int ff_sws_solve_shuffle	(	const SwsOpList *	ops,
		uint8_t	shuffle[],
		int	size,
		uint8_t	clear_val,
		int *	read_bytes,
		int *	write_bytes
	)

"Solve" an op list into a fixed shuffle mask, with an optional ability to also directly clear the output value (for e.g.

rgb24 -> rgb0). This can accept any operation chain that only consists of the following operations:

SWS_OP_READ (non-planar, non-fractional)
SWS_OP_SWIZZLE
SWS_OP_SWAP_BYTES
SWS_OP_CLEAR to zero (when clear_val is specified)
SWS_OP_CONVERT (integer expand)
SWS_OP_WRITE (non-planar, non-fractional)

Basically, any operation that purely consists of moving around and reordering bytes within a single plane, can be turned into a shuffle mask.

Parameters

ops	The operation list to decompose.
shuffle	The output shuffle mask.
size	The size (in bytes) of the output shuffle mask.
clear_val	If nonzero, this index will be used to clear the output.
read_bytes	Returns the number of bytes read per shuffle iteration.
write_bytes	Returns the number of bytes written per shuffle iteration.

Returns: The number of pixels processed per iteration, or a negative error code; in particular AVERROR(ENOTSUP) for unsupported operations.

Definition at line 843 of file ops_optimizer.c.

Referenced by solve_shuffle().

Variable Documentation

◆ flags_identity

const unsigned flags_identity = SWS_COMP_ZERO | SWS_COMP_EXACT

static

Definition at line 150 of file ops_optimizer.c.

Referenced by ff_sws_op_list_update_comps().

Macros

Functions

Variables

Macro Definition Documentation

◆ RET

Function Documentation

◆ op_commute_clear()

◆ op_commute_swizzle()

◆ merge_comp_flags()

◆ ff_sws_op_list_update_comps()

◆ exact_log2()

◆ exact_log2_q()

◆ extract_scalar()

◆ extract_constant_rows()

◆ extract_swizzle()

◆ ff_sws_op_list_optimize()

◆ ff_sws_solve_shuffle()

Variable Documentation

◆ flags_identity