From 1704a88ea3c38a8c496340bf58a71ca5a3be94a4 Mon Sep 17 00:00:00 2001
From: Nishant Mehta <nishantmehta.n@gmail.com>
Date: Wed, 24 Jun 2026 11:16:50 -0400
Subject: [PATCH] Add steady-state decode benchmark

BenchmarkDecode is skipped unless -oggfile is given and rebuilds the decoder
and re-parses the stream every iteration, so it cannot track per-frame decode
cost by default. Add BenchmarkDecodeSteady, which runs on the embedded
tiny.ogg: it parses the packets once, reuses a single decoder and output
buffer, warms up scratch, then loops the same packets. This isolates the
recurring per-frame work (currently 0 allocs/op) from one-time setup.
---
 decode_steady_bench_test.go | 56 +++++++++++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 decode_steady_bench_test.go

diff --git a/decode_steady_bench_test.go b/decode_steady_bench_test.go
new file mode 100644
index 0000000..0733128
--- /dev/null
+++ b/decode_steady_bench_test.go
@@ -0,0 +1,56 @@
+// SPDX-FileCopyrightText: 2026 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+package opus
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"testing"
+
+	"github.com/pion/opus/pkg/oggreader"
+)
+
+// BenchmarkDecodeSteady measures the steady-state, per-frame decode cost. Unlike
+// BenchmarkDecode -- which is skipped unless -oggfile is given, and which rebuilds the
+// decoder and re-parses the stream on every iteration -- this benchmark runs by default
+// on the embedded tiny.ogg: it parses the packets once, reuses a single decoder and
+// output buffer, warms up the decoder's scratch buffers, and then loops over the same
+// packets. That isolates the recurring per-frame work from one-time setup.
+func BenchmarkDecodeSteady(b *testing.B) {
+	var pkts [][]byte
+	ogg, _, err := oggreader.NewWith(bytes.NewReader(tinyogg))
+	if err != nil {
+		b.Fatal(err)
+	}
+	for {
+		segments, _, err := ogg.ParseNextPage()
+		if errors.Is(err, io.EOF) {
+			break
+		}
+		if err != nil {
+			b.Fatal(err)
+		}
+		if len(segments) > 0 && bytes.HasPrefix(segments[0], []byte("OpusTags")) {
+			continue
+		}
+		pkts = append(pkts, segments...)
+	}
+
+	decoder := NewDecoder()
+	var out [1920]byte
+	// Warm up the decoder's scratch buffers so the timed loop measures steady state.
+	for i := range pkts {
+		_, _, _ = decoder.Decode(pkts[i], out[:]) //nolint:errcheck // warm-up only
+	}
+
+	b.ResetTimer()
+	for range b.N {
+		for i := range pkts {
+			if _, _, err := decoder.Decode(pkts[i], out[:]); err != nil {
+				b.Fatal(err)
+			}
+		}
+	}
+}