Import aom library

This is the reference implementation for the Alliance for Open Media's av1 video code.

The commit used was 4d668d7feb1f8abd809d1bca0418570a7f142a36.

1 files changed, 378 insertions, 0 deletions

diff --git a/third_party/aom/av1/decoder/pvq_decoder.c b/third_party/aom/av1/decoder/pvq_decoder.c
new file mode 100644
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+/*
+ * Copyright (c) 2001-2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+/* clang-format off */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "./aom_config.h"
+#include "aom_dsp/bitreader.h"
+#include "aom_dsp/entcode.h"
+#include "aom_dsp/entdec.h"
+#include "av1/common/odintrin.h"
+#include "av1/common/partition.h"
+#include "av1/common/pvq_state.h"
+#include "av1/decoder/decint.h"
+#include "av1/decoder/pvq_decoder.h"
+#include "aom_ports/system_state.h"
+
+int aom_read_symbol_pvq_(aom_reader *r, aom_cdf_prob *cdf, int nsymbs
+ ACCT_STR_PARAM) {
+  if (cdf[0] == 0)
+    aom_cdf_init_q15_1D(cdf, nsymbs, CDF_SIZE(nsymbs));
+  return aom_read_symbol(r, cdf, nsymbs, ACCT_STR_NAME);
+}
+
+static void aom_decode_pvq_codeword(aom_reader *r, od_pvq_codeword_ctx *ctx,
+ od_coeff *y, int n, int k) {
+  int i;
+  aom_decode_band_pvq_splits(r, ctx, y, n, k, 0);
+  for (i = 0; i < n; i++) {
+    if (y[i] && aom_read_bit(r, "pvq:sign")) y[i] = -y[i];
+  }
+}
+
+/** Inverse of neg_interleave; decodes the interleaved gain.
+ *
+ * @param [in]      x      quantized/interleaved gain to decode
+ * @param [in]      ref    quantized gain of the reference
+ * @return                 original quantized gain value
+ */
+static int neg_deinterleave(int x, int ref) {
+  if (x < 2*ref-1) {
+    if (x & 1) return ref - 1 - (x >> 1);
+    else return ref + (x >> 1);
+  }
+  else return x+1;
+}
+
+/** Synthesizes one parition of coefficient values from a PVQ-encoded
+ * vector.
+ *
+ * @param [out]     xcoeff  output coefficient partition (x in math doc)
+ * @param [in]      ypulse  PVQ-encoded values (y in math doc); in the noref
+ *                          case, this vector has n entries, in the
+ *                          reference case it contains n-1 entries
+ *                          (the m-th entry is not included)
+ * @param [in]      ref     reference vector (prediction)
+ * @param [in]      n       number of elements in this partition
+ * @param [in]      gr      gain of the reference vector (prediction)
+ * @param [in]      noref   indicates presence or lack of prediction
+ * @param [in]      g       decoded quantized vector gain
+ * @param [in]      theta   decoded theta (prediction error)
+ * @param [in]      qm      QM with magnitude compensation
+ * @param [in]      qm_inv  Inverse of QM with magnitude compensation
+ */
+static void pvq_synthesis(od_coeff *xcoeff, od_coeff *ypulse, od_val16 *r16,
+ int n, od_val32 gr, int noref, od_val32 g, od_val32 theta, const int16_t *qm_inv,
+ int shift) {
+  int s;
+  int m;
+  /* Sign of the Householder reflection vector */
+  s = 0;
+  /* Direction of the Householder reflection vector */
+  m = noref ? 0 : od_compute_householder(r16, n, gr, &s, shift);
+  od_pvq_synthesis_partial(xcoeff, ypulse, r16, n, noref, g, theta, m, s,
+   qm_inv);
+}
+
+typedef struct {
+  od_coeff *ref;
+  int nb_coeffs;
+  int allow_flip;
+} cfl_ctx;
+
+/** Decodes a single vector of integers (eg, a partition within a
+ *  coefficient block) encoded using PVQ
+ *
+ * @param [in,out] ec          range encoder
+ * @param [in]     q0          scale/quantizer
+ * @param [in]     n           number of coefficients in partition
+ * @param [in,out] model       entropy decoder state
+ * @param [in,out] adapt       adaptation context
+ * @param [in,out] exg         ExQ16 expectation of decoded gain value
+ * @param [in,out] ext         ExQ16 expectation of decoded theta value
+ * @param [in]     ref         'reference' (prediction) vector
+ * @param [out]    out         decoded partition
+ * @param [out]    noref       boolean indicating absence of reference
+ * @param [in]     beta        per-band activity masking beta param
+ * @param [in]     is_keyframe whether we're encoding a keyframe
+ * @param [in]     pli         plane index
+ * @param [in]     cdf_ctx     selects which cdf context to use
+ * @param [in,out] skip_rest   whether to skip further bands in each direction
+ * @param [in]     band        index of the band being decoded
+ * @param [in]     band        index of the band being decoded
+ * @param [out]    skip        skip flag with range [0,1]
+ * @param [in]     qm          QM with magnitude compensation
+ * @param [in]     qm_inv      Inverse of QM with magnitude compensation
+ */
+static void pvq_decode_partition(aom_reader *r,
+                                 int q0,
+                                 int n,
+                                 generic_encoder model[3],
+                                 od_adapt_ctx *adapt,
+                                 int *exg,
+                                 int *ext,
+                                 od_coeff *ref,
+                                 od_coeff *out,
+                                 int *noref,
+                                 od_val16 beta,
+                                 int is_keyframe,
+                                 int pli,
+                                 int cdf_ctx,
+                                 cfl_ctx *cfl,
+                                 int has_skip,
+                                 int *skip_rest,
+                                 int band,
+                                 int *skip,
+                                 const int16_t *qm,
+                                 const int16_t *qm_inv) {
+  int k;
+  od_val32 qcg;
+  int itheta;
+  od_val32 theta;
+  od_val32 gr;
+  od_val32 gain_offset;
+  od_coeff y[MAXN];
+  int qg;
+  int id;
+  int i;
+  od_val16 ref16[MAXN];
+  int rshift;
+  theta = 0;
+  gr = 0;
+  gain_offset = 0;
+  /* Skip is per-direction. For band=0, we can use any of the flags. */
+  if (skip_rest[(band + 2) % 3]) {
+    qg = 0;
+    if (is_keyframe) {
+      itheta = -1;
+      *noref = 1;
+    }
+    else {
+      itheta = 0;
+      *noref = 0;
+    }
+  }
+  else {
+    /* Jointly decode gain, itheta and noref for small values. Then we handle
+       larger gain. */
+    id = aom_read_symbol_pvq(r, &adapt->pvq.pvq_gaintheta_cdf[cdf_ctx][0],
+     8 + 7*has_skip, "pvq:gaintheta");
+    if (!is_keyframe && id >= 10) id++;
+    if (is_keyframe && id >= 8) id++;
+    if (id >= 8) {
+      id -= 8;
+      skip_rest[0] = skip_rest[1] = skip_rest[2] = 1;
+    }
+    qg = id & 1;
+    itheta = (id >> 1) - 1;
+    *noref = (itheta == -1);
+  }
+  /* The CfL flip bit is only decoded on the first band that has noref=0. */
+  if (cfl->allow_flip && !*noref) {
+    int flip;
+    flip = aom_read_bit(r, "cfl:flip");
+    if (flip) {
+      for (i = 0; i < cfl->nb_coeffs; i++) cfl->ref[i] = -cfl->ref[i];
+    }
+    cfl->allow_flip = 0;
+  }
+  if (qg > 0) {
+    int tmp;
+    tmp = *exg;
+    qg = 1 + generic_decode(r, &model[!*noref], &tmp, 2, "pvq:gain");
+    OD_IIR_DIADIC(*exg, qg << 16, 2);
+  }
+  *skip = 0;
+#if defined(OD_FLOAT_PVQ)
+  rshift = 0;
+#else
+  /* Shift needed to make the reference fit in 15 bits, so that the Householder
+     vector can fit in 16 bits. */
+  rshift = OD_MAXI(0, od_vector_log_mag(ref, n) - 14);
+#endif
+  for (i = 0; i < n; i++) {
+#if defined(OD_FLOAT_PVQ)
+    ref16[i] = ref[i]*(double)qm[i]*OD_QM_SCALE_1;
+#else
+    ref16[i] = OD_SHR_ROUND(ref[i]*qm[i], OD_QM_SHIFT + rshift);
+#endif
+  }
+  if(!*noref){
+    /* we have a reference; compute its gain */
+    od_val32 cgr;
+    int icgr;
+    int cfl_enabled;
+    cfl_enabled = pli != 0 && is_keyframe && !OD_DISABLE_CFL;
+    cgr = od_pvq_compute_gain(ref16, n, q0, &gr, beta, rshift);
+    if (cfl_enabled) cgr = OD_CGAIN_SCALE;
+#if defined(OD_FLOAT_PVQ)
+    icgr = (int)floor(.5 + cgr);
+#else
+    icgr = OD_SHR_ROUND(cgr, OD_CGAIN_SHIFT);
+#endif
+    /* quantized gain is interleave encoded when there's a reference;
+       deinterleave it now */
+    if (is_keyframe) qg = neg_deinterleave(qg, icgr);
+    else {
+      qg = neg_deinterleave(qg, icgr + 1) - 1;
+      if (qg == 0) *skip = (icgr ? OD_PVQ_SKIP_ZERO : OD_PVQ_SKIP_COPY);
+    }
+    if (qg == icgr && itheta == 0 && !cfl_enabled) *skip = OD_PVQ_SKIP_COPY;
+    gain_offset = cgr - OD_SHL(icgr, OD_CGAIN_SHIFT);
+    qcg = OD_SHL(qg, OD_CGAIN_SHIFT) + gain_offset;
+    /* read and decode first-stage PVQ error theta */
+    if (itheta > 1) {
+      int tmp;
+      tmp = *ext;
+      itheta = 2 + generic_decode(r, &model[2], &tmp, 2, "pvq:theta");
+      OD_IIR_DIADIC(*ext, itheta << 16, 2);
+    }
+    theta = od_pvq_compute_theta(itheta, od_pvq_compute_max_theta(qcg, beta));
+  }
+  else{
+    itheta = 0;
+    if (!is_keyframe) qg++;
+    qcg = OD_SHL(qg, OD_CGAIN_SHIFT);
+    if (qg == 0) *skip = OD_PVQ_SKIP_ZERO;
+  }
+
+  k = od_pvq_compute_k(qcg, itheta, *noref, n, beta);
+  if (k != 0) {
+    /* when noref==0, y is actually size n-1 */
+    aom_decode_pvq_codeword(r, &adapt->pvq.pvq_codeword_ctx, y,
+     n - !*noref, k);
+  }
+  else {
+    OD_CLEAR(y, n);
+  }
+  if (*skip) {
+    if (*skip == OD_PVQ_SKIP_COPY) OD_COPY(out, ref, n);
+    else OD_CLEAR(out, n);
+  }
+  else {
+    od_val32 g;
+    g = od_gain_expand(qcg, q0, beta);
+    pvq_synthesis(out, y, ref16, n, gr, *noref, g, theta, qm_inv, rshift);
+  }
+  /* If OD_PVQ_SKIP_ZERO or OD_PVQ_SKIP_COPY, set skip to 1 for visualization */
+  if (*skip) *skip = 1;
+}
+
+/** Decodes a coefficient block (except for DC) encoded using PVQ
+ *
+ * @param [in,out] dec         daala decoder context
+ * @param [in]     ref         'reference' (prediction) vector
+ * @param [out]    out         decoded partition
+ * @param [in]     q0          quantizer
+ * @param [in]     pli         plane index
+ * @param [in]     bs          log of the block size minus two
+ * @param [in]     beta        per-band activity masking beta param
+ * @param [in]     is_keyframe whether we're encoding a keyframe
+ * @param [out]    flags       bitmask of the per band skip and noref flags
+ * @param [in]     ac_dc_coded skip flag for the block (range 0-3)
+ * @param [in]     qm          QM with magnitude compensation
+ * @param [in]     qm_inv      Inverse of QM with magnitude compensation
+ */
+void od_pvq_decode(daala_dec_ctx *dec,
+                   od_coeff *ref,
+                   od_coeff *out,
+                   int q0,
+                   int pli,
+                   int bs,
+                   const od_val16 *beta,
+                   int is_keyframe,
+                   unsigned int *flags,
+                   PVQ_SKIP_TYPE ac_dc_coded,
+                   const int16_t *qm,
+                   const int16_t *qm_inv){
+
+  int noref[PVQ_MAX_PARTITIONS];
+  int skip[PVQ_MAX_PARTITIONS];
+  int *exg;
+  int *ext;
+  int nb_bands;
+  int i;
+  const int *off;
+  int size[PVQ_MAX_PARTITIONS];
+  generic_encoder *model;
+  int skip_rest[3] = {0};
+  cfl_ctx cfl;
+  const unsigned char *pvq_qm;
+  int use_masking;
+
+  aom_clear_system_state();
+
+  /*Default to skip=1 and noref=0 for all bands.*/
+  for (i = 0; i < PVQ_MAX_PARTITIONS; i++) {
+    noref[i] = 0;
+    skip[i] = 1;
+  }
+
+  use_masking = dec->use_activity_masking;
+
+  if (use_masking)
+    pvq_qm = &dec->state.pvq_qm_q4[pli][0];
+  else
+    pvq_qm = 0;
+
+  exg = &dec->state.adapt->pvq.pvq_exg[pli][bs][0];
+  ext = dec->state.adapt->pvq.pvq_ext + bs*PVQ_MAX_PARTITIONS;
+  model = dec->state.adapt->pvq.pvq_param_model;
+  nb_bands = OD_BAND_OFFSETS[bs][0];
+  off = &OD_BAND_OFFSETS[bs][1];
+  out[0] = ac_dc_coded & DC_CODED;
+  if (ac_dc_coded < AC_CODED) {
+    if (is_keyframe) for (i = 1; i < 1 << (2*bs + 4); i++) out[i] = 0;
+    else for (i = 1; i < 1 << (2*bs + 4); i++) out[i] = ref[i];
+  }
+  else {
+    for (i = 0; i < nb_bands; i++) size[i] = off[i+1] - off[i];
+    cfl.ref = ref;
+    cfl.nb_coeffs = off[nb_bands];
+    cfl.allow_flip = pli != 0 && is_keyframe;
+    for (i = 0; i < nb_bands; i++) {
+      int q;
+
+      if (use_masking)
+        q = OD_MAXI(1, q0 * pvq_qm[od_qm_get_index(bs, i + 1)] >> 4);
+      else
+        q = OD_MAXI(1, q0);
+
+      pvq_decode_partition(dec->r, q, size[i],
+       model, dec->state.adapt, exg + i, ext + i, ref + off[i], out + off[i],
+       &noref[i], beta[i], is_keyframe, pli,
+       (pli != 0)*OD_TXSIZES*PVQ_MAX_PARTITIONS + bs*PVQ_MAX_PARTITIONS + i,
+       &cfl, i == 0 && (i < nb_bands - 1), skip_rest, i, &skip[i],
+       qm + off[i], qm_inv + off[i]);
+      if (i == 0 && !skip_rest[0] && bs > 0) {
+        int skip_dir;
+        int j;
+        skip_dir = aom_read_symbol(dec->r,
+         &dec->state.adapt->pvq.pvq_skip_dir_cdf[(pli != 0) + 2*(bs - 1)][0], 7,
+         "pvq:skiprest");
+        for (j = 0; j < 3; j++) skip_rest[j] = !!(skip_dir & (1 << j));
+      }
+    }
+  }
+  *flags = 0;
+  for (i = nb_bands - 1; i >= 0; i--) {
+    *flags <<= 1;
+    *flags |= noref[i]&1;
+    *flags <<= 1;
+    *flags |= skip[i]&1;
+  }
+}