ffmpeg/libavutil/tx.c

686 lines
20 KiB
C

/*
* 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 "avassert.h"
#include "cpu.h"
#include "qsort.h"
#include "bprint.h"
#include "tx_priv.h"
#define TYPE_IS(type, x) \
(((x) == AV_TX_FLOAT_ ## type) || \
((x) == AV_TX_DOUBLE_ ## type) || \
((x) == AV_TX_INT32_ ## type))
/* Calculates the modular multiplicative inverse */
static av_always_inline int mulinv(int n, int m)
{
n = n % m;
for (int x = 1; x < m; x++)
if (((n * x) % m) == 1)
return x;
av_assert0(0); /* Never reached */
return 0;
}
/* Guaranteed to work for any n, m where gcd(n, m) == 1 */
int ff_tx_gen_compound_mapping(AVTXContext *s, int n, int m)
{
int *in_map, *out_map;
const int inv = s->inv;
const int len = n*m; /* Will not be equal to s->len for MDCTs */
int m_inv, n_inv;
/* Make sure the numbers are coprime */
if (av_gcd(n, m) != 1)
return AVERROR(EINVAL);
m_inv = mulinv(m, n);
n_inv = mulinv(n, m);
if (!(s->map = av_malloc(2*len*sizeof(*s->map))))
return AVERROR(ENOMEM);
in_map = s->map;
out_map = s->map + len;
/* Ruritanian map for input, CRT map for output, can be swapped */
for (int j = 0; j < m; j++) {
for (int i = 0; i < n; i++) {
in_map[j*n + i] = (i*m + j*n) % len;
out_map[(i*m*m_inv + j*n*n_inv) % len] = i*m + j;
}
}
/* Change transform direction by reversing all ACs */
if (inv) {
for (int i = 0; i < m; i++) {
int *in = &in_map[i*n + 1]; /* Skip the DC */
for (int j = 0; j < ((n - 1) >> 1); j++)
FFSWAP(int, in[j], in[n - j - 2]);
}
}
/* Our 15-point transform is also a compound one, so embed its input map */
if (n == 15) {
for (int k = 0; k < m; k++) {
int tmp[15];
memcpy(tmp, &in_map[k*15], 15*sizeof(*tmp));
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 3; j++)
in_map[k*15 + i*3 + j] = tmp[(i*3 + j*5) % 15];
}
}
}
return 0;
}
static inline int split_radix_permutation(int i, int len, int inv)
{
len >>= 1;
if (len <= 1)
return i & 1;
if (!(i & len))
return split_radix_permutation(i, len, inv) * 2;
len >>= 1;
return split_radix_permutation(i, len, inv) * 4 + 1 - 2*(!(i & len) ^ inv);
}
int ff_tx_gen_ptwo_revtab(AVTXContext *s, int invert_lookup)
{
int len = s->len;
if (!(s->map = av_malloc(len*sizeof(*s->map))))
return AVERROR(ENOMEM);
if (invert_lookup) {
for (int i = 0; i < s->len; i++)
s->map[i] = -split_radix_permutation(i, len, s->inv) & (len - 1);
} else {
for (int i = 0; i < s->len; i++)
s->map[-split_radix_permutation(i, len, s->inv) & (len - 1)] = i;
}
return 0;
}
int ff_tx_gen_ptwo_inplace_revtab_idx(AVTXContext *s)
{
int *src_map, out_map_idx = 0, len = s->len;
if (!s->sub || !s->sub->map)
return AVERROR(EINVAL);
if (!(s->map = av_mallocz(len*sizeof(*s->map))))
return AVERROR(ENOMEM);
src_map = s->sub->map;
/* The first coefficient is always already in-place */
for (int src = 1; src < s->len; src++) {
int dst = src_map[src];
int found = 0;
if (dst <= src)
continue;
/* This just checks if a closed loop has been encountered before,
* and if so, skips it, since to fully permute a loop we must only
* enter it once. */
do {
for (int j = 0; j < out_map_idx; j++) {
if (dst == s->map[j]) {
found = 1;
break;
}
}
dst = src_map[dst];
} while (dst != src && !found);
if (!found)
s->map[out_map_idx++] = src;
}
s->map[out_map_idx++] = 0;
return 0;
}
static void parity_revtab_generator(int *revtab, int n, int inv, int offset,
int is_dual, int dual_high, int len,
int basis, int dual_stride, int inv_lookup)
{
len >>= 1;
if (len <= basis) {
int k1, k2, stride, even_idx, odd_idx;
is_dual = is_dual && dual_stride;
dual_high = is_dual & dual_high;
stride = is_dual ? FFMIN(dual_stride, len) : 0;
even_idx = offset + dual_high*(stride - 2*len);
odd_idx = even_idx + len + (is_dual && !dual_high)*len + dual_high*len;
for (int i = 0; i < len; i++) {
k1 = -split_radix_permutation(offset + i*2 + 0, n, inv) & (n - 1);
k2 = -split_radix_permutation(offset + i*2 + 1, n, inv) & (n - 1);
if (inv_lookup) {
revtab[even_idx++] = k1;
revtab[odd_idx++] = k2;
} else {
revtab[k1] = even_idx++;
revtab[k2] = odd_idx++;
}
if (stride && !((i + 1) % stride)) {
even_idx += stride;
odd_idx += stride;
}
}
return;
}
parity_revtab_generator(revtab, n, inv, offset,
0, 0, len >> 0, basis, dual_stride, inv_lookup);
parity_revtab_generator(revtab, n, inv, offset + (len >> 0),
1, 0, len >> 1, basis, dual_stride, inv_lookup);
parity_revtab_generator(revtab, n, inv, offset + (len >> 0) + (len >> 1),
1, 1, len >> 1, basis, dual_stride, inv_lookup);
}
int ff_tx_gen_split_radix_parity_revtab(AVTXContext *s, int len, int inv,
int inv_lookup, int basis, int dual_stride)
{
basis >>= 1;
if (len < basis)
return AVERROR(EINVAL);
if (!(s->map = av_mallocz(len*sizeof(*s->map))))
return AVERROR(ENOMEM);
av_assert0(!dual_stride || !(dual_stride & (dual_stride - 1)));
av_assert0(dual_stride <= basis);
parity_revtab_generator(s->map, len, inv, 0, 0, 0, len,
basis, dual_stride, inv_lookup != 0);
return 0;
}
static void reset_ctx(AVTXContext *s)
{
if (!s)
return;
if (s->sub)
for (int i = 0; i < s->nb_sub; i++)
reset_ctx(&s->sub[i]);
if (s->cd_self->uninit)
s->cd_self->uninit(s);
av_freep(&s->sub);
av_freep(&s->map);
av_freep(&s->exp);
av_freep(&s->tmp);
memset(s, 0, sizeof(*s));
}
av_cold void av_tx_uninit(AVTXContext **ctx)
{
if (!(*ctx))
return;
reset_ctx(*ctx);
av_freep(ctx);
}
static av_cold int ff_tx_null_init(AVTXContext *s, const FFTXCodelet *cd,
uint64_t flags, FFTXCodeletOptions *opts,
int len, int inv, const void *scale)
{
/* Can only handle one sample+type to one sample+type transforms */
if (TYPE_IS(MDCT, s->type) || TYPE_IS(RDFT, s->type))
return AVERROR(EINVAL);
return 0;
}
/* Null transform when the length is 1 */
static void ff_tx_null(AVTXContext *s, void *_out, void *_in, ptrdiff_t stride)
{
memcpy(_out, _in, stride);
}
static const FFTXCodelet ff_tx_null_def = {
.name = NULL_IF_CONFIG_SMALL("null"),
.function = ff_tx_null,
.type = TX_TYPE_ANY,
.flags = AV_TX_UNALIGNED | FF_TX_ALIGNED |
FF_TX_OUT_OF_PLACE | AV_TX_INPLACE,
.factors[0] = TX_FACTOR_ANY,
.min_len = 1,
.max_len = 1,
.init = ff_tx_null_init,
.cpu_flags = FF_TX_CPU_FLAGS_ALL,
.prio = FF_TX_PRIO_MAX,
};
static const FFTXCodelet * const ff_tx_null_list[] = {
&ff_tx_null_def,
NULL,
};
#if !CONFIG_SMALL
static void print_flags(AVBPrint *bp, uint64_t f)
{
int prev = 0;
const char *sep = ", ";
av_bprintf(bp, "flags: [");
if ((f & FF_TX_ALIGNED) && ++prev)
av_bprintf(bp, "aligned");
if ((f & AV_TX_UNALIGNED) && ++prev)
av_bprintf(bp, "%sunaligned", prev > 1 ? sep : "");
if ((f & AV_TX_INPLACE) && ++prev)
av_bprintf(bp, "%sinplace", prev > 1 ? sep : "");
if ((f & FF_TX_OUT_OF_PLACE) && ++prev)
av_bprintf(bp, "%sout_of_place", prev > 1 ? sep : "");
if ((f & FF_TX_FORWARD_ONLY) && ++prev)
av_bprintf(bp, "%sfwd_only", prev > 1 ? sep : "");
if ((f & FF_TX_INVERSE_ONLY) && ++prev)
av_bprintf(bp, "%sinv_only", prev > 1 ? sep : "");
if ((f & FF_TX_PRESHUFFLE) && ++prev)
av_bprintf(bp, "%spreshuf", prev > 1 ? sep : "");
if ((f & AV_TX_FULL_IMDCT) && ++prev)
av_bprintf(bp, "%simdct_full", prev > 1 ? sep : "");
if ((f & FF_TX_ASM_CALL) && ++prev)
av_bprintf(bp, "%sasm_call", prev > 1 ? sep : "");
av_bprintf(bp, "]");
}
static void print_type(AVBPrint *bp, enum AVTXType type)
{
av_bprintf(bp, "%s",
type == TX_TYPE_ANY ? "any" :
type == AV_TX_FLOAT_FFT ? "fft_float" :
type == AV_TX_FLOAT_MDCT ? "mdct_float" :
type == AV_TX_FLOAT_RDFT ? "rdft_float" :
type == AV_TX_DOUBLE_FFT ? "fft_double" :
type == AV_TX_DOUBLE_MDCT ? "mdct_double" :
type == AV_TX_DOUBLE_RDFT ? "rdft_double" :
type == AV_TX_INT32_FFT ? "fft_int32" :
type == AV_TX_INT32_MDCT ? "mdct_int32" :
type == AV_TX_INT32_RDFT ? "rdft_int32" :
"unknown");
}
static void print_cd_info(const FFTXCodelet *cd, int prio, int print_prio)
{
AVBPrint bp = { 0 };
av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
av_bprintf(&bp, "%s - type: ", cd->name);
print_type(&bp, cd->type);
av_bprintf(&bp, ", len: ");
if (cd->min_len != cd->max_len)
av_bprintf(&bp, "[%i, ", cd->min_len);
if (cd->max_len == TX_LEN_UNLIMITED)
av_bprintf(&bp, "");
else
av_bprintf(&bp, "%i", cd->max_len);
av_bprintf(&bp, "%s, factors: [", cd->min_len != cd->max_len ? "]" : "");
for (int i = 0; i < TX_MAX_SUB; i++) {
if (i && cd->factors[i])
av_bprintf(&bp, ", ");
if (cd->factors[i] == TX_FACTOR_ANY)
av_bprintf(&bp, "any");
else if (cd->factors[i])
av_bprintf(&bp, "%i", cd->factors[i]);
else
break;
}
av_bprintf(&bp, "], ");
print_flags(&bp, cd->flags);
if (print_prio)
av_bprintf(&bp, ", prio: %i", prio);
av_log(NULL, AV_LOG_DEBUG, "%s\n", bp.str);
}
static void print_tx_structure(AVTXContext *s, int depth)
{
const FFTXCodelet *cd = s->cd_self;
for (int i = 0; i <= depth; i++)
av_log(NULL, AV_LOG_DEBUG, " ");
print_cd_info(cd, cd->prio, 0);
for (int i = 0; i < s->nb_sub; i++)
print_tx_structure(&s->sub[i], depth + 1);
}
#endif /* CONFIG_SMALL */
typedef struct TXCodeletMatch {
const FFTXCodelet *cd;
int prio;
} TXCodeletMatch;
static int cmp_matches(TXCodeletMatch *a, TXCodeletMatch *b)
{
return FFDIFFSIGN(b->prio, a->prio);
}
/* We want all factors to completely cover the length */
static inline int check_cd_factors(const FFTXCodelet *cd, int len)
{
int all_flag = 0;
for (int i = 0; i < TX_MAX_SUB; i++) {
int factor = cd->factors[i];
/* Conditions satisfied */
if (len == 1)
return 1;
/* No more factors */
if (!factor) {
break;
} else if (factor == TX_FACTOR_ANY) {
all_flag = 1;
continue;
}
if (factor == 2) { /* Fast path */
int bits_2 = ff_ctz(len);
if (!bits_2)
return 0; /* Factor not supported */
len >>= bits_2;
} else {
int res = len % factor;
if (res)
return 0; /* Factor not supported */
while (!res) {
len /= factor;
res = len % factor;
}
}
}
return all_flag || (len == 1);
}
av_cold int ff_tx_init_subtx(AVTXContext *s, enum AVTXType type,
uint64_t flags, FFTXCodeletOptions *opts,
int len, int inv, const void *scale)
{
int ret = 0;
AVTXContext *sub = NULL;
TXCodeletMatch *cd_tmp, *cd_matches = NULL;
unsigned int cd_matches_size = 0;
int nb_cd_matches = 0;
#if !CONFIG_SMALL
AVBPrint bp = { 0 };
#endif
/* Array of all compiled codelet lists. Order is irrelevant. */
const FFTXCodelet * const * const codelet_list[] = {
ff_tx_codelet_list_float_c,
ff_tx_codelet_list_double_c,
ff_tx_codelet_list_int32_c,
ff_tx_null_list,
#if HAVE_X86ASM
ff_tx_codelet_list_float_x86,
#endif
#if ARCH_AARCH64
ff_tx_codelet_list_float_aarch64,
#endif
};
int codelet_list_num = FF_ARRAY_ELEMS(codelet_list);
/* We still accept functions marked with SLOW, even if the CPU is
* marked with the same flag, but we give them lower priority. */
const int cpu_flags = av_get_cpu_flags();
const int slow_mask = AV_CPU_FLAG_SSE2SLOW | AV_CPU_FLAG_SSE3SLOW |
AV_CPU_FLAG_ATOM | AV_CPU_FLAG_SSSE3SLOW |
AV_CPU_FLAG_AVXSLOW | AV_CPU_FLAG_SLOW_GATHER;
static const int slow_penalties[][2] = {
{ AV_CPU_FLAG_SSE2SLOW, 1 + 64 },
{ AV_CPU_FLAG_SSE3SLOW, 1 + 64 },
{ AV_CPU_FLAG_SSSE3SLOW, 1 + 64 },
{ AV_CPU_FLAG_ATOM, 1 + 128 },
{ AV_CPU_FLAG_AVXSLOW, 1 + 128 },
{ AV_CPU_FLAG_SLOW_GATHER, 1 + 32 },
};
/* Flags the transform wants */
uint64_t req_flags = flags;
/* Flags the codelet may require to be present */
uint64_t inv_req_mask = AV_TX_FULL_IMDCT | FF_TX_PRESHUFFLE | FF_TX_ASM_CALL;
/* Unaligned codelets are compatible with the aligned flag */
if (req_flags & FF_TX_ALIGNED)
req_flags |= AV_TX_UNALIGNED;
/* If either flag is set, both are okay, so don't check for an exact match */
if ((req_flags & AV_TX_INPLACE) && (req_flags & FF_TX_OUT_OF_PLACE))
req_flags &= ~(AV_TX_INPLACE | FF_TX_OUT_OF_PLACE);
if ((req_flags & FF_TX_ALIGNED) && (req_flags & AV_TX_UNALIGNED))
req_flags &= ~(FF_TX_ALIGNED | AV_TX_UNALIGNED);
/* Loop through all codelets in all codelet lists to find matches
* to the requirements */
while (codelet_list_num--) {
const FFTXCodelet * const * list = codelet_list[codelet_list_num];
const FFTXCodelet *cd = NULL;
while ((cd = *list++)) {
int max_factor = 0;
/* Check if the type matches */
if (cd->type != TX_TYPE_ANY && type != cd->type)
continue;
/* Check direction for non-orthogonal codelets */
if (((cd->flags & FF_TX_FORWARD_ONLY) && inv) ||
((cd->flags & (FF_TX_INVERSE_ONLY | AV_TX_FULL_IMDCT)) && !inv))
continue;
/* Check if the requested flags match from both sides */
if (((req_flags & cd->flags) != (req_flags)) ||
((inv_req_mask & cd->flags) != (req_flags & inv_req_mask)))
continue;
/* Check if length is supported */
if ((len < cd->min_len) || (cd->max_len != -1 && (len > cd->max_len)))
continue;
/* Check if the CPU supports the required ISA */
if (cd->cpu_flags != FF_TX_CPU_FLAGS_ALL &&
!(cpu_flags & (cd->cpu_flags & ~slow_mask)))
continue;
/* Check for factors */
if (!check_cd_factors(cd, len))
continue;
/* Realloc array and append */
cd_tmp = av_fast_realloc(cd_matches, &cd_matches_size,
sizeof(*cd_tmp) * (nb_cd_matches + 1));
if (!cd_tmp) {
av_free(cd_matches);
return AVERROR(ENOMEM);
}
cd_matches = cd_tmp;
cd_matches[nb_cd_matches].cd = cd;
cd_matches[nb_cd_matches].prio = cd->prio;
/* If the CPU has a SLOW flag, and the instruction is also flagged
* as being slow for such, reduce its priority */
for (int i = 0; i < FF_ARRAY_ELEMS(slow_penalties); i++) {
if ((cpu_flags & cd->cpu_flags) & slow_penalties[i][0])
cd_matches[nb_cd_matches].prio -= slow_penalties[i][1];
}
/* Prioritize aligned-only codelets */
if ((cd->flags & FF_TX_ALIGNED) && !(cd->flags & AV_TX_UNALIGNED))
cd_matches[nb_cd_matches].prio += 64;
/* Codelets for specific lengths are generally faster */
if ((len == cd->min_len) && (len == cd->max_len))
cd_matches[nb_cd_matches].prio += 64;
/* Forward-only or inverse-only transforms are generally better */
if ((cd->flags & (FF_TX_FORWARD_ONLY | FF_TX_INVERSE_ONLY)))
cd_matches[nb_cd_matches].prio += 64;
/* Larger factors are generally better */
for (int i = 0; i < TX_MAX_SUB; i++)
max_factor = FFMAX(cd->factors[i], max_factor);
if (max_factor)
cd_matches[nb_cd_matches].prio += 16*max_factor;
nb_cd_matches++;
}
}
#if !CONFIG_SMALL
/* Print debugging info */
av_bprint_init(&bp, 0, AV_BPRINT_SIZE_AUTOMATIC);
av_bprintf(&bp, "For transform of length %i, %s, ", len,
inv ? "inverse" : "forward");
print_type(&bp, type);
av_bprintf(&bp, ", ");
print_flags(&bp, flags);
av_bprintf(&bp, ", found %i matches%s", nb_cd_matches,
nb_cd_matches ? ":" : ".");
#endif
/* No matches found */
if (!nb_cd_matches)
return AVERROR(ENOSYS);
/* Sort the list */
AV_QSORT(cd_matches, nb_cd_matches, TXCodeletMatch, cmp_matches);
#if !CONFIG_SMALL
av_log(NULL, AV_LOG_DEBUG, "%s\n", bp.str);
for (int i = 0; i < nb_cd_matches; i++) {
av_log(NULL, AV_LOG_DEBUG, " %i: ", i + 1);
print_cd_info(cd_matches[i].cd, cd_matches[i].prio, 1);
}
#endif
if (!s->sub) {
s->sub = sub = av_mallocz(TX_MAX_SUB*sizeof(*sub));
if (!sub) {
ret = AVERROR(ENOMEM);
goto end;
}
}
/* Attempt to initialize each */
for (int i = 0; i < nb_cd_matches; i++) {
const FFTXCodelet *cd = cd_matches[i].cd;
AVTXContext *sctx = &s->sub[s->nb_sub];
sctx->len = len;
sctx->inv = inv;
sctx->type = type;
sctx->flags = cd->flags | flags;
sctx->cd_self = cd;
s->fn[s->nb_sub] = cd->function;
s->cd[s->nb_sub] = cd;
ret = 0;
if (cd->init)
ret = cd->init(sctx, cd, flags, opts, len, inv, scale);
if (ret >= 0) {
s->nb_sub++;
goto end;
}
s->fn[s->nb_sub] = NULL;
s->cd[s->nb_sub] = NULL;
reset_ctx(sctx);
if (ret == AVERROR(ENOMEM))
break;
}
if (!s->nb_sub)
av_freep(&s->sub);
end:
av_free(cd_matches);
return ret;
}
av_cold int av_tx_init(AVTXContext **ctx, av_tx_fn *tx, enum AVTXType type,
int inv, int len, const void *scale, uint64_t flags)
{
int ret;
AVTXContext tmp = { 0 };
const double default_scale_d = 1.0;
const float default_scale_f = 1.0f;
if (!len || type >= AV_TX_NB || !ctx || !tx)
return AVERROR(EINVAL);
if (!(flags & AV_TX_UNALIGNED))
flags |= FF_TX_ALIGNED;
if (!(flags & AV_TX_INPLACE))
flags |= FF_TX_OUT_OF_PLACE;
if (!scale && ((type == AV_TX_FLOAT_MDCT) || (type == AV_TX_INT32_MDCT)))
scale = &default_scale_f;
else if (!scale && (type == AV_TX_DOUBLE_MDCT))
scale = &default_scale_d;
ret = ff_tx_init_subtx(&tmp, type, flags, NULL, len, inv, scale);
if (ret < 0)
return ret;
*ctx = &tmp.sub[0];
*tx = tmp.fn[0];
#if !CONFIG_SMALL
av_log(NULL, AV_LOG_DEBUG, "Transform tree:\n");
print_tx_structure(*ctx, 0);
#endif
return ret;
}