-/// Time/frequency Grid (14496-3 sp04 p200)
-static int sbr_time_freq_grid(AACContext *ac, SpectralBandReplication *sbr,
- SBRData *ch_data, int ch)
-{
- int abs_bord_lead = ch_data->bs_frame_class >= 2 ? ch_data->bs_var_bord[0] : 0;
- // frameLengthFlag ? 15 : 16; 960 sample length frames unsupported; this value is numTimeSlots
- int abs_bord_trail = (ch_data->bs_frame_class & 1 ? ch_data->bs_var_bord[1] : 0) + 16;
- int n_rel_lead;
- int i;
-
- if (ch_data->bs_frame_class == FIXFIX) {
- n_rel_lead = ch_data->bs_num_env[1] - 1;
- } else if (ch_data->bs_frame_class == FIXVAR) {
- n_rel_lead = 0;
- } else if (ch_data->bs_frame_class < 4) { // VARFIX or VARVAR
- n_rel_lead = ch_data->bs_num_rel[0];
- } else {
- av_log(ac->avccontext, AV_LOG_ERROR,
- "Invalid bs_frame_class for SBR: %d\n", ch_data->bs_frame_class);
- return -1;
- }
-
- ch_data->t_env_num_env_old = ch_data->t_env[ch_data->bs_num_env[0]];
- ch_data->t_env[0] = abs_bord_lead;
- ch_data->t_env[ch_data->bs_num_env[1]] = abs_bord_trail;
-
- if (ch_data->bs_frame_class == FIXFIX) {
- int temp = (abs_bord_trail + (ch_data->bs_num_env[1] >> 1)) /
- ch_data->bs_num_env[1];
- for (i = 0; i < n_rel_lead; i++)
- ch_data->t_env[i + 1] = ch_data->t_env[i] + temp;
- } else if (ch_data->bs_frame_class > 1) { // VARFIX or VARVAR
- for (i = 0; i < n_rel_lead; i++)
- ch_data->t_env[i + 1] = ch_data->t_env[i] + ch_data->bs_rel_bord[0][i];
- } else { // FIXVAR
- for (i = 0; i < n_rel_lead; i++)
- ch_data->t_env[i + 1] = abs_bord_lead;
- }
-
- if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR
- for (i = ch_data->bs_num_env[1] - 1; i > n_rel_lead; i--)
- ch_data->t_env[i] = ch_data->t_env[i + 1] -
- ch_data->bs_rel_bord[1][ch_data->bs_num_env[1] - 1 - i];
- } else { // FIXFIX or VARFIX
- for (i = n_rel_lead; i < ch_data->bs_num_env[1]; i++)
- ch_data->t_env[i + 1] = abs_bord_trail;
- }
-
- ch_data->t_q[0] = ch_data->t_env[0];
- if (ch_data->bs_num_noise > 1) { // typo in spec bases this on bs_num_env...
- unsigned int idx;
- if (ch_data->bs_frame_class == FIXFIX) {
- idx = ch_data->bs_num_env[1] >> 1;
- } else if (ch_data->bs_frame_class & 1) { // FIXVAR or VARVAR
- idx = ch_data->bs_num_env[1] - FFMAX(ch_data->bs_pointer - 1, 1);
- } else { // VARFIX
- if (!ch_data->bs_pointer)
- idx = 1;
- else if (ch_data->bs_pointer == 1)
- idx = ch_data->bs_num_env[1] - 1;
- else // bs_pointer > 1
- idx = ch_data->bs_pointer - 1;
- }
- ch_data->t_q[1] = ch_data->t_env[idx];
- ch_data->t_q[2] = ch_data->t_env[ch_data->bs_num_env[1]];
- } else
- ch_data->t_q[1] = ch_data->t_env[ch_data->bs_num_env[1]];
-
- return 0;
-}
-