Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 935 insertions, 0 deletions

diff --git a/media/ffvpx/libavutil/tx.c b/media/ffvpx/libavutil/tx.c
new file mode 100644
index 0000000000..a1f767039b
--- /dev/null
+++ b/media/ffvpx/libavutil/tx.c
@@ -0,0 +1,935 @@
+/*
+ * 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 "intmath.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;
+}
+
+int ff_tx_gen_pfa_input_map(AVTXContext *s, FFTXCodeletOptions *opts,
+                            int d1, int d2)
+{
+    const int sl = d1*d2;
+
+    s->map = av_malloc(s->len*sizeof(*s->map));
+    if (!s->map)
+        return AVERROR(ENOMEM);
+
+    for (int k = 0; k < s->len; k += sl) {
+        if (s->inv || (opts && opts->map_dir == FF_TX_MAP_SCATTER)) {
+            for (int m = 0; m < d2; m++)
+                for (int n = 0; n < d1; n++)
+                    s->map[k + ((m*d1 + n*d2) % (sl))] = m*d1 + n;
+        } else {
+            for (int m = 0; m < d2; m++)
+                for (int n = 0; n < d1; n++)
+                    s->map[k + m*d1 + n] = (m*d1 + n*d2) % (sl);
+        }
+
+        if (s->inv)
+            for (int w = 1; w <= ((sl) >> 1); w++)
+                FFSWAP(int, s->map[k + w], s->map[k + sl - w]);
+    }
+
+    s->map_dir = opts ? opts->map_dir : FF_TX_MAP_GATHER;
+
+    return 0;
+}
+
+/* Guaranteed to work for any n, m where gcd(n, m) == 1 */
+int ff_tx_gen_compound_mapping(AVTXContext *s, FFTXCodeletOptions *opts,
+                               int inv, int n, int m)
+{
+    int *in_map, *out_map;
+    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 */
+    if (opts && opts->map_dir == FF_TX_MAP_SCATTER) {
+        for (int j = 0; j < m; j++) {
+            for (int i = 0; i < n; i++) {
+                in_map[(i*m + j*n) % len] = j*n + i;
+                out_map[(i*m*m_inv + j*n*n_inv) % len] = i*m + j;
+            }
+        }
+    } else {
+        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;
+            }
+        }
+    }
+
+    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]);
+        }
+    }
+
+    s->map_dir = opts ? opts->map_dir : FF_TX_MAP_GATHER;
+
+    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, FFTXCodeletOptions *opts)
+{
+    int len = s->len;
+
+    if (!(s->map = av_malloc(len*sizeof(*s->map))))
+        return AVERROR(ENOMEM);
+
+    if (opts && opts->map_dir == FF_TX_MAP_SCATTER) {
+        for (int i = 0; i < s->len; i++)
+            s->map[-split_radix_permutation(i, len, s->inv) & (len - 1)] = i;
+    } else {
+        for (int i = 0; i < s->len; i++)
+            s->map[i] = -split_radix_permutation(i, len, s->inv) & (len - 1);
+    }
+
+    s->map_dir = opts ? opts->map_dir : FF_TX_MAP_GATHER;
+
+    return 0;
+}
+
+int ff_tx_gen_inplace_map(AVTXContext *s, int len)
+{
+    int *src_map, out_map_idx = 0;
+
+    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,
+                                        FFTXCodeletOptions *opts,
+                                        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,
+                            opts ? opts->map_dir == FF_TX_MAP_GATHER : FF_TX_MAP_GATHER);
+
+    s->map_dir = opts ? opts->map_dir : FF_TX_MAP_GATHER;
+
+    return 0;
+}
+
+static void reset_ctx(AVTXContext *s, int free_sub)
+{
+    if (!s)
+        return;
+
+    if (s->sub)
+        for (int i = 0; i < TX_MAX_SUB; i++)
+            reset_ctx(&s->sub[i], free_sub + 1);
+
+    if (s->cd_self && s->cd_self->uninit)
+        s->cd_self->uninit(s);
+
+    if (free_sub)
+        av_freep(&s->sub);
+
+    av_freep(&s->map);
+    av_freep(&s->exp);
+    av_freep(&s->tmp);
+
+    /* Nothing else needs to be reset, it gets overwritten if another
+     * ff_tx_init_subtx() call is made. */
+    s->nb_sub = 0;
+    s->opaque = NULL;
+    memset(s->fn, 0, sizeof(*s->fn));
+}
+
+void ff_tx_clear_ctx(AVTXContext *s)
+{
+    reset_ctx(s, 0);
+}
+
+av_cold void av_tx_uninit(AVTXContext **ctx)
+{
+    if (!(*ctx))
+        return;
+
+    reset_ctx(*ctx, 1);
+    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,
+};
+
+/* Array of all compiled codelet lists. Order is irrelevant. */
+static 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
+};
+static const int codelet_list_num = FF_ARRAY_ELEMS(codelet_list);
+
+static const int cpu_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 cpu_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  },
+};
+
+static int get_codelet_prio(const FFTXCodelet *cd, int cpu_flags, int len)
+{
+    int prio = cd->prio;
+    int max_factor = 0;
+
+    /* 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(cpu_slow_penalties); i++) {
+        if ((cpu_flags & cd->cpu_flags) & cpu_slow_penalties[i][0])
+            prio -= cpu_slow_penalties[i][1];
+    }
+
+    /* Prioritize aligned-only codelets */
+    if ((cd->flags & FF_TX_ALIGNED) && !(cd->flags & AV_TX_UNALIGNED))
+        prio += 64;
+
+    /* Codelets for specific lengths are generally faster */
+    if ((len == cd->min_len) && (len == cd->max_len))
+        prio += 64;
+
+    /* Forward-only or inverse-only transforms are generally better */
+    if ((cd->flags & (FF_TX_FORWARD_ONLY | FF_TX_INVERSE_ONLY)))
+        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)
+        prio += 16*max_factor;
+
+    return prio;
+}
+
+typedef struct FFTXLenDecomp {
+    int len;
+    int len2;
+    int prio;
+    const FFTXCodelet *cd;
+} FFTXLenDecomp;
+
+static int cmp_decomp(FFTXLenDecomp *a, FFTXLenDecomp *b)
+{
+    return FFDIFFSIGN(b->prio, a->prio);
+}
+
+int ff_tx_decompose_length(int dst[TX_MAX_DECOMPOSITIONS], enum AVTXType type,
+                           int len, int inv)
+{
+    int nb_decomp = 0;
+    FFTXLenDecomp ld[TX_MAX_DECOMPOSITIONS];
+    int codelet_list_idx = codelet_list_num;
+
+    const int cpu_flags = av_get_cpu_flags();
+
+    /* Loop through all codelets in all codelet lists to find matches
+     * to the requirements */
+    while (codelet_list_idx--) {
+        const FFTXCodelet * const * list = codelet_list[codelet_list_idx];
+        const FFTXCodelet *cd = NULL;
+
+        while ((cd = *list++)) {
+            int fl = len;
+            int skip = 0, prio;
+            int factors_product = 1, factors_mod = 0;
+
+            if (nb_decomp >= TX_MAX_DECOMPOSITIONS)
+                goto sort;
+
+            /* 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) ||
+                ((cd->flags & (FF_TX_FORWARD_ONLY | AV_TX_REAL_TO_REAL)) && inv) ||
+                ((cd->flags & (FF_TX_FORWARD_ONLY | AV_TX_REAL_TO_IMAGINARY)) && inv))
+                continue;
+
+            /* Check if the CPU supports the required ISA */
+            if (cd->cpu_flags != FF_TX_CPU_FLAGS_ALL &&
+                !(cpu_flags & (cd->cpu_flags & ~cpu_slow_mask)))
+                continue;
+
+            for (int i = 0; i < TX_MAX_FACTORS; i++) {
+                if (!cd->factors[i] || (fl == 1))
+                    break;
+
+                if (cd->factors[i] == TX_FACTOR_ANY) {
+                    factors_mod++;
+                    factors_product *= fl;
+                } else if (!(fl % cd->factors[i])) {
+                    factors_mod++;
+                    if (cd->factors[i] == 2) {
+                        int b = ff_ctz(fl);
+                        fl >>= b;
+                        factors_product <<= b;
+                    } else {
+                        do {
+                            fl /= cd->factors[i];
+                            factors_product *= cd->factors[i];
+                        } while (!(fl % cd->factors[i]));
+                    }
+                }
+            }
+
+            /* Disqualify if factor requirements are not satisfied or if trivial */
+            if ((factors_mod < cd->nb_factors) || (len == factors_product))
+                continue;
+
+            if (av_gcd(factors_product, fl) != 1)
+                continue;
+
+            /* Check if length is supported and factorization was successful */
+            if ((factors_product < cd->min_len) ||
+                (cd->max_len != TX_LEN_UNLIMITED && (factors_product > cd->max_len)))
+                continue;
+
+            prio = get_codelet_prio(cd, cpu_flags, factors_product) * factors_product;
+
+            /* Check for duplicates */
+            for (int i = 0; i < nb_decomp; i++) {
+                if (factors_product == ld[i].len) {
+                    /* Update priority if new one is higher */
+                    if (prio > ld[i].prio)
+                        ld[i].prio = prio;
+                    skip = 1;
+                    break;
+                }
+            }
+
+            /* Add decomposition if unique */
+            if (!skip) {
+                ld[nb_decomp].cd = cd;
+                ld[nb_decomp].len = factors_product;
+                ld[nb_decomp].len2 = fl;
+                ld[nb_decomp].prio = prio;
+                nb_decomp++;
+            }
+        }
+    }
+
+    if (!nb_decomp)
+        return AVERROR(EINVAL);
+
+sort:
+    AV_QSORT(ld, nb_decomp, FFTXLenDecomp, cmp_decomp);
+
+    for (int i = 0; i < nb_decomp; i++) {
+        if (ld[i].cd->nb_factors > 1)
+            dst[i] = ld[i].len2;
+        else
+            dst[i] = ld[i].len;
+    }
+
+    return nb_decomp;
+}
+
+int ff_tx_gen_default_map(AVTXContext *s, FFTXCodeletOptions *opts)
+{
+    s->map = av_malloc(s->len*sizeof(*s->map));
+    if (!s->map)
+        return AVERROR(ENOMEM);
+
+    s->map[0] = 0; /* DC is always at the start */
+    if (s->inv) /* Reversing the ACs flips the transform direction */
+        for (int i = 1; i < s->len; i++)
+            s->map[i] = s->len - i;
+    else
+        for (int i = 1; i < s->len; i++)
+            s->map[i] = i;
+
+    s->map_dir = FF_TX_MAP_GATHER;
+
+    return 0;
+}
+
+#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 & AV_TX_REAL_TO_REAL) && ++prev)
+        av_bprintf(bp, "%sreal_to_real", prev > 1 ? sep : "");
+    if ((f & AV_TX_REAL_TO_IMAGINARY) && ++prev)
+        av_bprintf(bp, "%sreal_to_imaginary", 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_FLOAT_DCT_I ? "dctI_float"  :
+               type == AV_TX_FLOAT_DST_I ? "dstI_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_DOUBLE_DCT_I ? "dctI_double" :
+               type == AV_TX_DOUBLE_DST_I ? "dstI_double" :
+               type == AV_TX_INT32_FFT   ? "fft_int32"   :
+               type == AV_TX_INT32_MDCT  ? "mdct_int32"  :
+               type == AV_TX_INT32_RDFT  ? "rdft_int32"  :
+               type == AV_TX_INT32_DCT_I ? "dctI_int32" :
+               type == AV_TX_INT32_DST_I ? "dstI_int32" :
+               "unknown");
+}
+
+static void print_cd_info(const FFTXCodelet *cd, int prio, int len, int print_prio)
+{
+    AVBPrint bp;
+    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 (!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, "unlimited");
+        else
+            av_bprintf(&bp, "%i", cd->max_len);
+    } else {
+        av_bprintf(&bp, "%i", len);
+    }
+
+    if (cd->factors[1]) {
+        av_bprintf(&bp, "%s, factors", !len && cd->min_len != cd->max_len ? "]" : "");
+        if (!cd->nb_factors)
+            av_bprintf(&bp, ": [");
+        else
+            av_bprintf(&bp, "[%i]: [", cd->nb_factors);
+
+        for (int i = 0; i < TX_MAX_FACTORS; 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, "], ");
+    } else {
+        av_bprintf(&bp, "%s, factor: %i, ",
+                   !len && cd->min_len != cd->max_len ? "]" : "", cd->factors[0]);
+    }
+    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, s->len, 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 matches = 0, any_flag = 0;
+
+    for (int i = 0; i < TX_MAX_FACTORS; i++) {
+        int factor = cd->factors[i];
+
+        if (factor == TX_FACTOR_ANY) {
+            any_flag = 1;
+            matches++;
+            continue;
+        } else if (len <= 1 || !factor) {
+            break;
+        } else if (factor == 2) { /* Fast path */
+            int bits_2 = ff_ctz(len);
+            if (!bits_2)
+                continue; /* Factor not supported */
+
+            len >>= bits_2;
+            matches++;
+        } else {
+            int res = len % factor;
+            if (res)
+                continue; /* Factor not supported */
+
+            while (!res) {
+                len /= factor;
+                res = len % factor;
+            }
+            matches++;
+        }
+    }
+
+    return (cd->nb_factors <= matches) && (any_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 codelet_list_idx = codelet_list_num;
+    int nb_cd_matches = 0;
+#if !CONFIG_SMALL
+    AVBPrint bp;
+#endif
+
+    /* 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();
+
+    /* 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 |
+                            AV_TX_REAL_TO_REAL |
+                            AV_TX_REAL_TO_IMAGINARY |
+                            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_idx--) {
+        const FFTXCodelet * const * list = codelet_list[codelet_list_idx];
+        const FFTXCodelet *cd = NULL;
+
+        while ((cd = *list++)) {
+            /* 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) ||
+                ((cd->flags & (FF_TX_FORWARD_ONLY | AV_TX_REAL_TO_REAL)) && inv) ||
+                ((cd->flags & (FF_TX_FORWARD_ONLY | AV_TX_REAL_TO_IMAGINARY)) && 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 & ~cpu_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 = get_codelet_prio(cd, cpu_flags, len);
+            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, 0, 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) {
+            if (opts && opts->map_dir != FF_TX_MAP_NONE &&
+                sctx->map_dir == FF_TX_MAP_NONE) {
+                /* If a specific map direction was requested, and it doesn't
+                 * exist, create one.*/
+                sctx->map = av_malloc(len*sizeof(*sctx->map));
+                if (!sctx->map) {
+                    ret = AVERROR(ENOMEM);
+                    goto end;
+                }
+
+                for (int i = 0; i < len; i++)
+                    sctx->map[i] = i;
+            } else if (opts && (opts->map_dir != sctx->map_dir)) {
+                int *tmp = av_malloc(len*sizeof(*sctx->map));
+                if (!tmp) {
+                    ret = AVERROR(ENOMEM);
+                    goto end;
+                }
+
+                memcpy(tmp, sctx->map, len*sizeof(*sctx->map));
+
+                for (int i = 0; i < len; i++)
+                    sctx->map[tmp[i]] = i;
+
+                av_free(tmp);
+            }
+
+            s->nb_sub++;
+            goto end;
+        }
+
+        s->fn[s->nb_sub] = NULL;
+        s->cd[s->nb_sub] = NULL;
+
+        reset_ctx(sctx, 0);
+        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;
+}