feat(capability): 转码能力包（vendor 纯 Go AMR-NB 解码器 + 黄金向量逐样本对照 + 8 哨兵 + 注册面）

internal/capability/transcode/amrnb/dsp_enc_cb10.go

@@ -0,0 +1,96 @@
+package amrnb
+
+// 10-pulse algebraic codebook search (35 bits, MR122), ported from
+// opencore-amrnb c1035pf.cpp. Reuses search10and8i40 (10 pulses, step 5), then
+// builds the codeword (±4096 pulses) and Gray-encodes the per-track position
+// indices (q_p). The exact encoder counterpart of dec10i40_35bits. Bit-exact
+// with the reference.
+
+// build10Code assembles the 10-pulse innovation cod, filtered code y, and the
+// raw per-track position+sign indices (with the same-track ordering/swap logic
+// that the decoder inverts). Mirrors build_code (c1035pf.cpp).
+func build10Code(codvec, sign, cod, h, y, indx []int16) {
+	const L = cL_CODE
+	for i := 0; i < L; i++ {
+		cod[i] = 0
+	}
+	for t := 0; t < 5; t++ {
+		indx[t] = -1
+	}
+
+	var sgn [10]int16
+	for k := 0; k < 10; k++ {
+		i := codvec[k]
+		index := int16((int32(i) * 6554) >> 15)
+		track := i - (index + (index << 2)) // i - index*5
+
+		if sign[i] > 0 {
+			cod[i] += 4096
+			sgn[k] = 8192
+		} else {
+			cod[i] -= 4096
+			sgn[k] = -8192
+			index += 8
+		}
+
+		temp := indx[track]
+		switch {
+		case temp < 0:
+			indx[track] = index
+		case (index^temp)&8 == 0:
+			if temp <= index {
+				indx[track+5] = index
+			} else {
+				indx[track+5] = temp
+				indx[track] = index
+			}
+		default:
+			if (temp & 7) <= (index & 7) {
+				indx[track+5] = temp
+				indx[track] = index
+			} else {
+				indx[track+5] = index
+			}
+		}
+	}
+
+	for i := 0; i < L; i++ {
+		var s int32
+		for k := 0; k < 10; k++ {
+			ci := int(codvec[k])
+			var hv int16
+			if i-ci >= 0 {
+				hv = h[i-ci]
+			}
+			s += (int32(hv) * int32(sgn[k])) >> 7
+		}
+		y[i] = int16((s + 0x80) >> 8)
+	}
+}
+
+// code10i40_35bits runs the full MR122 10-pulse search, writing the innovation
+// cod, filtered code y, and the 10-value Gray-coded index. Mirrors
+// code_10i40_35bits.
+func code10i40_35bits(x, cn, h, cod, y, indx []int16) {
+	var dn, sign [cL_CODE]int16
+	var rr [cL_CODE * cL_CODE]int16
+	var ipos, codvec [10]int16
+	var posMax [5]int16
+
+	corHX(h, x, dn[:], 2)
+	setSign12k2(dn[:], cn, sign[:], posMax[:], 5, ipos[:], 5)
+	corH(h, sign[:], rr[:])
+	search10and8i40(10, 5, 5, dn[:], rr[:], ipos[:], posMax[:], codvec[:])
+	build10Code(codvec[:], sign[:], cod, h, y, indx)
+
+	// q_p: Gray-encode each track's position index (keeping the sign bit for the
+	// first five).
+	for n := 0; n < 10; n++ {
+		tmp := indx[n]
+		if n < 5 {
+			indx[n] = (tmp & 0x8) | gray[tmp&0x7]
+		} else {
+			indx[n] = gray[tmp&0x7]
+		}
+	}
+}