Files
FFmpeg/libswscale/ops_internal.h
Niklas Haas 291e849ee3 swscale/ops_optimizer: add ff_sws_op_list_split_planes()
Can be used to extract a reduced subset of operations affecting only certain
output planes, e.g. splitting an op list into a "memcpy" and a "non-memcpy"
part, or splitting apart op lists for independent or subsampled planes.

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Niklas Haas <git@haasn.dev>
2026-06-23 11:48:13 +00:00

114 lines
4.3 KiB
C

/**
* Copyright (C) 2025 Niklas Haas
*
* 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 SWSCALE_OPS_INTERNAL_H
#define SWSCALE_OPS_INTERNAL_H
#include "libavutil/mem_internal.h"
#include "ops.h"
#include "ops_dispatch.h"
#define Q(N) ((AVRational) { N, 1 })
static inline AVRational ff_sws_pixel_expand(SwsPixelType from, SwsPixelType to)
{
const int src = ff_sws_pixel_type_size(from);
const int dst = ff_sws_pixel_type_size(to);
if (src > dst)
return Q(0);
int scale = 1;
for (int i = 1; i < dst / src; i++)
scale = (scale << (src * 8)) | 1;
return Q(scale);
}
static inline void ff_sws_pack_op_decode(const SwsOp *op, uint64_t mask[4], int shift[4])
{
int size = 0;
for (int i = 0; i < 4; i++)
size += op->pack.pattern[i];
for (int i = 0; i < 4; i++) {
const int bits = op->pack.pattern[i];
mask[i] = (UINT64_C(1) << bits) - 1;
shift[i] = (i ? shift[i - 1] : size) - bits;
}
}
/**
* "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.
*
* @param ops The operation list to decompose.
* @param shuffle The output shuffle mask.
* @param size The size (in bytes) of the output shuffle mask.
* @param clear_val If nonzero, this index will be used to clear the output.
* @param read_bytes Returns the number of bytes read per shuffle iteration.
* @param write_bytes Returns the number of bytes written per shuffle iteration.
*
* @return The number of pixels processed per iteration, or a negative error
code; in particular AVERROR(ENOTSUP) for unsupported operations.
*/
int ff_sws_solve_shuffle(const SwsOpList *ops, uint8_t shuffle[], int size,
uint8_t clear_val, int *read_bytes, int *write_bytes);
/**
* Split an op list into two at the given index. The split will be mediated
* by a set of planar read/write operations, plus a swizzle (if necessary)
* to re-order only used components. If a split is performed, both output
* lists will be optimized before returning.
*
* @param ops1 The first part of the split op list. Will be modified in-place.
* @param ops2 The second part of the split op list will be returned here, or
* NULL if no split was necessary.
* @param index The index of the operation to split before. The operation
* itself will be absent from `ops1` and instead moved to the
* start of `ops2`.
*
* Returnse 0 or a negative error code.
*/
int ff_sws_op_list_split_at(SwsOpList *ops1, SwsOpList **ops2, int index);
/**
* Reduce an op list into a reduced subset that operates only on a given
* subset of planes. No effect if the output is not planar, or if the plane
* mask is empty or equal to all planes.
*
* @param ops1 Updated in-place to contain only the selected planes.
* @param ops2 The removed remainder is returned here, or NULL if no-op.
* @param planes A mask of the plane indices to keep.
*
* Returns 0 or a negative error code.
*/
int ff_sws_op_list_split_planes(SwsOpList *ops1, SwsOpList **ops2, SwsCompMask planes);
#endif /* SWSCALE_OPS_INTERNAL_H */