+static void lame_apply_block_type(AacPsyChannel *ctx, FFPsyWindowInfo *wi, int uselongblock)
+{
+ int blocktype = ONLY_LONG_SEQUENCE;
+ if (uselongblock) {
+ if (ctx->next_window_seq == EIGHT_SHORT_SEQUENCE)
+ blocktype = LONG_STOP_SEQUENCE;
+ } else {
+ blocktype = EIGHT_SHORT_SEQUENCE;
+ if (ctx->next_window_seq == ONLY_LONG_SEQUENCE)
+ ctx->next_window_seq = LONG_START_SEQUENCE;
+ if (ctx->next_window_seq == LONG_STOP_SEQUENCE)
+ ctx->next_window_seq = EIGHT_SHORT_SEQUENCE;
+ }
+
+ wi->window_type[0] = ctx->next_window_seq;
+ ctx->next_window_seq = blocktype;
+}
+
+static FFPsyWindowInfo psy_lame_window(FFPsyContext *ctx, const float *audio,
+ const float *la, int channel, int prev_type)
+{
+ AacPsyContext *pctx = (AacPsyContext*) ctx->model_priv_data;
+ AacPsyChannel *pch = &pctx->ch[channel];
+ int grouping = 0;
+ int uselongblock = 1;
+ int attacks[AAC_NUM_BLOCKS_SHORT + 1] = { 0 };
+ int i;
+ FFPsyWindowInfo wi = { { 0 } };
+
+ if (la) {
+ float hpfsmpl[AAC_BLOCK_SIZE_LONG];
+ float const *pf = hpfsmpl;
+ float attack_intensity[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS];
+ float energy_subshort[(AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS];
+ float energy_short[AAC_NUM_BLOCKS_SHORT + 1] = { 0 };
+ const float *firbuf = la + (AAC_BLOCK_SIZE_SHORT/4 - PSY_LAME_FIR_LEN);
+ int j, att_sum = 0;
+
+ /* LAME comment: apply high pass filter of fs/4 */
+ for (i = 0; i < AAC_BLOCK_SIZE_LONG; i++) {
+ float sum1, sum2;
+ sum1 = firbuf[i + (PSY_LAME_FIR_LEN - 1) / 2];
+ sum2 = 0.0;
+ for (j = 0; j < ((PSY_LAME_FIR_LEN - 1) / 2) - 1; j += 2) {
+ sum1 += psy_fir_coeffs[j] * (firbuf[i + j] + firbuf[i + PSY_LAME_FIR_LEN - j]);
+ sum2 += psy_fir_coeffs[j + 1] * (firbuf[i + j + 1] + firbuf[i + PSY_LAME_FIR_LEN - j - 1]);
+ }
+ /* NOTE: The LAME psymodel expects it's input in the range -32768 to 32768. Tuning this for normalized floats would be difficult. */
+ hpfsmpl[i] = (sum1 + sum2) * 32768.0f;
+ }
+
+ /* Calculate the energies of each sub-shortblock */
+ for (i = 0; i < PSY_LAME_NUM_SUBBLOCKS; i++) {
+ energy_subshort[i] = pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 1) * PSY_LAME_NUM_SUBBLOCKS)];
+ assert(pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)] > 0);
+ attack_intensity[i] = energy_subshort[i] / pch->prev_energy_subshort[i + ((AAC_NUM_BLOCKS_SHORT - 2) * PSY_LAME_NUM_SUBBLOCKS + 1)];
+ energy_short[0] += energy_subshort[i];
+ }
+
+ for (i = 0; i < AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS; i++) {
+ float const *const pfe = pf + AAC_BLOCK_SIZE_LONG / (AAC_NUM_BLOCKS_SHORT * PSY_LAME_NUM_SUBBLOCKS);
+ float p = 1.0f;
+ for (; pf < pfe; pf++)
+ p = FFMAX(p, fabsf(*pf));
+ pch->prev_energy_subshort[i] = energy_subshort[i + PSY_LAME_NUM_SUBBLOCKS] = p;
+ energy_short[1 + i / PSY_LAME_NUM_SUBBLOCKS] += p;
+ /* NOTE: The indexes below are [i + 3 - 2] in the LAME source.
+ * Obviously the 3 and 2 have some significance, or this would be just [i + 1]
+ * (which is what we use here). What the 3 stands for is ambiguous, as it is both
+ * number of short blocks, and the number of sub-short blocks.
+ * It seems that LAME is comparing each sub-block to sub-block + 1 in the
+ * previous block.
+ */
+ if (p > energy_subshort[i + 1])
+ p = p / energy_subshort[i + 1];
+ else if (energy_subshort[i + 1] > p * 10.0f)
+ p = energy_subshort[i + 1] / (p * 10.0f);
+ else
+ p = 0.0;
+ attack_intensity[i + PSY_LAME_NUM_SUBBLOCKS] = p;
+ }
+
+ /* compare energy between sub-short blocks */
+ for (i = 0; i < (AAC_NUM_BLOCKS_SHORT + 1) * PSY_LAME_NUM_SUBBLOCKS; i++)
+ if (!attacks[i / PSY_LAME_NUM_SUBBLOCKS])
+ if (attack_intensity[i] > pch->attack_threshold)
+ attacks[i / PSY_LAME_NUM_SUBBLOCKS] = (i % PSY_LAME_NUM_SUBBLOCKS) + 1;
+
+ /* should have energy change between short blocks, in order to avoid periodic signals */
+ /* Good samples to show the effect are Trumpet test songs */
+ /* GB: tuned (1) to avoid too many short blocks for test sample TRUMPET */
+ /* RH: tuned (2) to let enough short blocks through for test sample FSOL and SNAPS */
+ for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++) {
+ float const u = energy_short[i - 1];
+ float const v = energy_short[i];
+ float const m = FFMAX(u, v);
+ if (m < 40000) { /* (2) */
+ if (u < 1.7f * v && v < 1.7f * u) { /* (1) */
+ if (i == 1 && attacks[0] < attacks[i])
+ attacks[0] = 0;
+ attacks[i] = 0;
+ }
+ }
+ att_sum += attacks[i];
+ }
+
+ if (attacks[0] <= pch->prev_attack)
+ attacks[0] = 0;
+
+ att_sum += attacks[0];
+ /* 3 below indicates the previous attack happened in the last sub-block of the previous sequence */
+ if (pch->prev_attack == 3 || att_sum) {
+ uselongblock = 0;
+
+ for (i = 1; i < AAC_NUM_BLOCKS_SHORT + 1; i++)
+ if (attacks[i] && attacks[i-1])
+ attacks[i] = 0;
+ }
+ } else {
+ /* We have no lookahead info, so just use same type as the previous sequence. */
+ uselongblock = !(prev_type == EIGHT_SHORT_SEQUENCE);
+ }
+
+ lame_apply_block_type(pch, &wi, uselongblock);
+
+ wi.window_type[1] = prev_type;
+ if (wi.window_type[0] != EIGHT_SHORT_SEQUENCE) {
+ wi.num_windows = 1;
+ wi.grouping[0] = 1;
+ if (wi.window_type[0] == LONG_START_SEQUENCE)
+ wi.window_shape = 0;
+ else
+ wi.window_shape = 1;
+ } else {
+ int lastgrp = 0;
+
+ wi.num_windows = 8;
+ wi.window_shape = 0;
+ for (i = 0; i < 8; i++) {
+ if (!((pch->next_grouping >> i) & 1))
+ lastgrp = i;
+ wi.grouping[lastgrp]++;
+ }
+ }
+
+ /* Determine grouping, based on the location of the first attack, and save for
+ * the next frame.
+ * FIXME: Move this to analysis.
+ * TODO: Tune groupings depending on attack location
+ * TODO: Handle more than one attack in a group
+ */
+ for (i = 0; i < 9; i++) {
+ if (attacks[i]) {
+ grouping = i;
+ break;
+ }
+ }
+ pch->next_grouping = window_grouping[grouping];
+
+ pch->prev_attack = attacks[8];
+
+ return wi;
+}