feat(mcap): add paced replay tooling

scripts/replay_mcap.sh

@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
+BUILD_DIR="${BUILD_DIR:-$ROOT_DIR/build}"
+REPLAY_BIN="${REPLAY_BIN:-$BUILD_DIR/mcap_replay_tester}"
+FFPLAY_BIN="${FFPLAY_BIN:-ffplay}"
+FFPLAY_ARGS="${FFPLAY_ARGS:-}"
+
+usage() {
+	cat <<'EOF'
+Usage:
+  replay_mcap.sh <input.mcap> [h264|h265]
+
+This replays MCAP video using the recorded timestamps and pipes frames to ffplay.
+The optional codec argument defaults to h264. Extra ffplay flags may be supplied
+via FFPLAY_ARGS, for example: FFPLAY_ARGS='-window_title replay'.
+EOF
+}
+
+if [[ "${1:-}" == "--help" || "${1:-}" == "-h" ]]; then
+	usage
+	exit 0
+fi
+
+if [[ $# -lt 1 || $# -gt 2 ]]; then
+	usage >&2
+	exit 1
+fi
+
+INPUT_PATH="$1"
+FORMAT="${2:-h264}"
+if [[ "$FORMAT" != "h264" && "$FORMAT" != "h265" ]]; then
+	echo "unsupported format: $FORMAT (expected h264 or h265)" >&2
+	exit 1
+fi
+
+if [[ ! -f "$INPUT_PATH" ]]; then
+	echo "input MCAP not found: $INPUT_PATH" >&2
+	exit 1
+fi
+if [[ ! -x "$REPLAY_BIN" ]]; then
+	echo "replay binary not found: $REPLAY_BIN" >&2
+	exit 1
+fi
+if ! command -v "$FFPLAY_BIN" >/dev/null 2>&1; then
+	echo "ffplay not found: $FFPLAY_BIN" >&2
+	exit 1
+fi
+
+extra_args=()
+if [[ -n "$FFPLAY_ARGS" ]]; then
+	# shellcheck disable=SC2206
+	extra_args=($FFPLAY_ARGS)
+fi
+
+cmd=(
+	"$REPLAY_BIN"
+	"$INPUT_PATH"
+	--expect-format "$FORMAT"
+	--ffplay-path "$FFPLAY_BIN"
+)
+
+for arg in "${extra_args[@]}"; do
+	cmd+=(--ffplay-arg "$arg")
+done
+
+"${cmd[@]}"