[lfnst] Add commandline option for lfnst. Implement cabac lfnst flag init and sps flag.

src/cabac.h

@@ -73,6 +73,7 @@ typedef struct
     cabac_ctx_t alf_cc_filter_control_flag[6];
     cabac_ctx_t sao_merge_flag_model;
     cabac_ctx_t sao_type_idx_model;
+    cabac_ctx_t lfnst_idx[3];
     cabac_ctx_t mts_idx_model[4];
     cabac_ctx_t split_flag_model[9]; //!< \brief split flag context models
     cabac_ctx_t qt_split_flag_model[6]; //!< \brief qt split flag context models

src/cfg.c

@@ -204,6 +204,8 @@ int uvg_config_init(uvg_config *cfg)
   
   cfg->mip = false;
 
+  cfg->lfnst = false;
+
   parse_qp_map(cfg, 0);
 
   cfg->jccr = 0;
@@ -1439,6 +1441,9 @@ int uvg_config_parse(uvg_config *cfg, const char *name, const char *value)
   else if OPT("mip") {
     cfg->mip = atobool(value);
   }
+  else if OPT("lfnst") {
+    cfg->lfnst = atobool(value);
+  }
   else if OPT("jccr") {
     cfg->jccr = (bool)atobool(value);
   }

src/cli.c

@@ -174,6 +174,8 @@ static const struct option long_options[] = {
   { "no-mrl",                   no_argument, NULL, 0 },
   { "mip",                      no_argument, NULL, 0 },
   { "no-mip",                   no_argument, NULL, 0 },
+  { "lfnst",                    no_argument, NULL, 0 },
+  { "no-lfnst",                 no_argument, NULL, 0 },
   { "jccr",                     no_argument, NULL, 0 },
   { "no-jccr",                  no_argument, NULL, 0 },
   { "amvr",                     no_argument, NULL, 0 },
@@ -647,6 +649,7 @@ void print_help(void)
     "      --(no-)mrl             : Enable use of multiple reference lines in intra\n"
     "                               predictions.\n"
     "      --(no-)mip             : Enable matrix weighted intra prediction.\n"
+    "      --(no-)lfnst           : Enable low frequency non-separable transform. [disabled]"
     "      --mts <string>         : Multiple Transform Selection [off].\n"
     "                               (Currently only implemented for intra\n"
     "                               and has effect only when rd >= 2)\n"

src/context.c

@@ -284,6 +284,13 @@ static const uint8_t INIT_SAO_MERGE_FLAG[4] = { 2, 60, 60, 0 };
 
 static const uint8_t INIT_SAO_TYPE_IDX[4] = { 2, 5, 13, 4 };
 
+static const uint8_t INIT_LFNST_IDX[4][3] = {
+  {  52,  37,  27, },
+  {  37,  45,  27, },
+  {  28,  52,  42, },
+  {   9,   9,  10, },
+};
+
 static const uint8_t INIT_MTS_IDX[4][4] = {
   {  45,  25,  27,   0, },
   {  45,  40,  27,   0, },
@@ -502,7 +509,8 @@ void uvg_init_contexts(encoder_state_t *state, int8_t QP, int8_t slice)
 
   for (i = 0; i < 3; i++) {
     uvg_ctx_init(&cabac->ctx.cu_skip_flag_model[i], QP, INIT_SKIP_FLAG[slice][i], INIT_SKIP_FLAG[3][i]);
-    uvg_ctx_init(&cabac->ctx.joint_cb_cr[i], QP, INIT_JOINT_CB_CR_FLAG[slice][i], INIT_JOINT_CB_CR_FLAG[3][i]);   
+    uvg_ctx_init(&cabac->ctx.joint_cb_cr[i], QP, INIT_JOINT_CB_CR_FLAG[slice][i], INIT_JOINT_CB_CR_FLAG[3][i]);  
+    uvg_ctx_init(&cabac->ctx.lfnst_idx[i], QP, INIT_LFNST_IDX[slice][i], INIT_LFNST_IDX[3][i]);
     uvg_ctx_init(&cabac->ctx.transform_skip_sig_coeff_group[i], QP, INIT_TRANSFORM_SKIP_SIG_COEFF_GROUP[slice][i], INIT_TRANSFORM_SKIP_SIG_COEFF_GROUP[3][i]);
     uvg_ctx_init(&cabac->ctx.transform_skip_sig[i], QP, INIT_TRANSFORM_SKIP_SIG[slice][i], INIT_TRANSFORM_SKIP_SIG[3][i]);
   }

src/encoder_state-bitstream.c

@@ -667,6 +667,12 @@ static void encoder_state_write_bitstream_seq_parameter_set(bitstream_t* stream,
   } else {
     WRITE_U(stream, 0, 1, "sps_mrl_enabled_flag");
   }
+
+  if (state->encoder_control->cfg.lfnst) {
+    WRITE_U(stream, 1, 1, "sps_lfnst_enabled_flag");
+  } else {
+    WRITE_U(stream, 0, 1, "sps_lfnst_enabled_flag");
+  }
   
   if (state->encoder_control->cfg.mip) {
     WRITE_U(stream, 1, 1, "sps_mip_enabled_flag");

src/uvg266.h

@@ -518,10 +518,12 @@ typedef struct uvg_config
   int8_t chroma_scale_out[3][17];
 
   /** \brief enable use of multiple reference lines in intra prediction */
-  int8_t mrl; 
+  int8_t mrl;
 
   /** \brief enable matrix weighted intra prediction */
   int8_t mip;
+  /** \brief enable low frequency non-separable transform */
+  int8_t lfnst;
 
 
   int8_t jccr;