+ PARA_NOTICE_LOG("amplification: %u (scaling factor: %1.2f)\n",
+ pad->amp, pad->amp / 64.0 + 1.0);
+}
+
+static void amp_post_select(__a_unused struct sched *s, struct task *t)
+{
+ struct filter_node *fn = container_of(t, struct filter_node, task);
+ struct private_amp_data *pad = fn->private_data;
+ struct btr_node *btrn = fn->btrn;
+ int ret, factor = 64 + pad->amp;
+ size_t i, in_bytes, len;
+ int16_t *in, *out;
+ bool inplace = btr_inplace_ok(btrn);
+
+ if (pad->amp == 0) { /* no amplification */
+ t->error = -E_AMP_ZERO_AMP;
+ btr_splice_out_node(btrn);
+ return;
+ }
+next_buffer:
+ ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
+ if (ret < 0)
+ goto err;
+ if (ret == 0)
+ return;
+ btr_merge(btrn, fn->min_iqs);
+ in_bytes = btr_next_buffer(btrn, (char **)&in);
+ len = in_bytes / 2;
+ if (len == 0) { /* eof and in_bytes == 1 */
+ ret = -E_AMP_EOF;
+ goto err;
+ }
+
+ if (inplace)
+ out = in;
+ else
+ out = para_malloc(len * 2);
+
+ for (i = 0; i < len; i++) {
+ int x = (in[i] * factor) >> 6;
+
+ out[i] = x;
+ if (out[i] != x) /* overflow, clip */
+ out[i] = (x >= 0)? 32767 : -32768;
+ }
+
+ if (inplace)
+ btr_pushdown_one(btrn);
+ else {
+ btr_consume(btrn, len * 2);
+ btr_add_output((char *)out, len * 2, btrn);
+ }
+ t->error = 0;
+ goto next_buffer;
+err:
+ assert(ret < 0);
+ t->error = ret;
+ btr_remove_node(btrn);
+}
+
+static void amp_free_config(void *conf)
+{
+ amp_cmdline_parser_free(conf);